Data from the

NATIONAL HEALTH SURVEY

FamilyBackground,

EarlyDevelopment,and

Intelligence

6-11Years

UnitedStates

of Children

The relationships of estimated intelligence of these children to

factors in their background, prenatal care, condition of the child

at birth, early developmental history, preschool educational experience, and present medical problems are analyzed.

DHEW Publication No. (HRA) 77-1624

U.S. DEPARTMENT OF HEALTH, EDUCATION, AND WELFARE

Public Health Service

Health Resources Administration

National Center for Health Statistics

Hyattsville, Md.

Series 11

Number 142
Vital and Health Statistics-Series 1l-No, 142

Reprinted as DHEW Publication No. (HRA) 77-1624

September 1977

First issued in the Public Health Service Publication Series No. 1000, August 1974
NATIONAL CENTER FOR HEALTH STATISTICS

DOROTHY P. RICE, Director

ROBERT A. ISRAEL, Deputy Director

JACOB J. FELDMAN, Ph.D., Associate Director for Analysis

GAIL F. FISHER, Associate Director for the Cooperative Health Statistics System

ELIJAH L. WHITE, Associate Director for Data Systems

JAMES T, BAIRD, JR., Ph.D., Associate Director for International Statistics

ROBERT C. HUBER, Associate Director for Management

MONROE G. SIRKEN, Ph. D., Associate Director for Mathematical Statistics

PETER L. HURLEY, Associate Director for Operations

JAMES M. ROBEY, Ph.D., Associate Director for Program Deve~opment

PAUL E. LEAVERTON, Ph. D., Associate Director for Research

ALICE HAYWOOD, Information Officer

Library of Congress Catalog Card Number 74-2102
CONTENTS

Page

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Sources and Limitations ofData . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Findings . . . .’. . . . ; . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . , . . . . . . . . . 3

Family Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Parent Education . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Relation to First Parent . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Birthplace of Mother . . . . . . . . ..0... . . . . . . . . . . . . . . . . . . . . . . . . . . 5

AgeofParents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Family Size . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ... . . . . . . . . 5

Age Order . . . . . . . . . . . . .’. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Prenatal Care, Co.mplications. . . . . . . . . . . . . . . . . . . . . . . . ..O . . . . . . . . . 9

Condition ofChildat”Birth . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Birthweight . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Length of Hospitalization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

CongenitalMalformations and Birth Injury . . . . . . . . . . . . . . . . . . . . . . . 10

Handedness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Twin Status . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ~~

Early Developmental History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Change from Breast Feeding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Walking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Speech . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

LearningSpeed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Healthatl Year . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Medical Problems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Medical History ofNeurological Problems . . . . . . . . . . . . . . . . . . . . . . . . 12

Medical Findings on Examination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Preschool Educational Experience . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Family Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ... 15

Condition ofChildatBirth . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Early Developmental History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Medical Problems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Preschool Experience . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 20

...

Ill
Page

Lkt of Detailed Tables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Appendix I. Statistical Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

The Survey Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

Reliability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

Sampling and Measurement Error . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

Small Categories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

Appendix II. Demographic and Socioeconomic Terms . . . . . . . . . . . . . . . . . . 38

Appendix HI. Household Questionnaire and Medical History Items . . . . . . . . 40

iv
SYMBOLS

Data not available ---------------------------------------- ---

Category not applicable ------------------------------- ., .

Quantity ~e~o ---------------------------------------------- -

Quantity more than O but less than 0.05 ----- 0.0

Figure does not meet standards of

reliability or precision ------------------------------

*

v
FAMILY BACKGROUND, EARLY DEVELOPMENT,

AND INTELLIGENCEOF CHILDREN 6-11 YEARS

Jean Roberts and Arnold Engel, M.D., Division of Health Examination Statistics

INTRODUCTION

This report contains national estimates of the

prevalence of selected congenital and early

developmental health problems and describes

the relationship of selected aspects of family

background, infant health status, and early

developmental history to the intellectual development and maturity of noninstitutionalized

children 6-11 years of age in the United States,

based on findings from the Health Examination

Survey of 1963-1965.

The Health Examination Survey is a major

program of the National Center for Health

Statistics which was established to carry out the

Health Survey Act of 1956, enacted by the 84th

Congress to provide for a continuing assessment

of the health status of the U.S. population.

Three different programs are utilized in the

National Health Survey. 1 The Health Interview

Survey collects health information from samples

of people by household interview. The Health

Resources programs obtain health data as well as

health resource and utilization information

through surveys of hospitals, nursing homes and

other resident institutions, and the entire range

of personnel in the health occupations. The

Health Examination Survey, from which the

national estimates in this report were obtained,

collects health data by direct physical examination, tests, and measurements performed on

samples of the population.

The Health Examination Survey has been

conducted as a series of separate programs, or

cycles, which were limited to some specific

segment of the noninstitutionalized population

and to specific aspects of health. In the first

cycle, data were obtained on the prevalence of

certain chronic diseases and the distribution of

various physical and physiological measures or

characteristics in a defined adult population.2 >3

,In the second cycle, on which this report is

based, a probability sample of the Nation’s

noninstitutionalized children 6-11 years of age

was selected and examined. The examination,

which focused primarily on health factors related to growth and development, included an

examination by a pediatrician, an examination

by a dentist, tests administered by a psychologist, and a variety of tests and measurements by

technicians. Prior to the examination, demographic and socioeconomic data on household

members as well as medical history, behavioral,

and related data on the child to be examined

were obtained from one of the parents, usually

the mother. Ancillary data for the child on grade

placement, teacher’s ratings of his behavior and

adjustment, and health problems known to the

teacher were requested from the school. Birth

certificates for verification of the age and

information related to the child at birth were

also obtained. The survey plan, sample design,

examination content, and operation of this

program have been described in detail previously.4

Field collection operations for this cycle

started in July 1963 and were completed in

December 1965. There were 7,119 children, or

96 percent, examined out of the total probability sample of 7,417 children selected. This

national sample is representative, and the group

of examinees is also closely representative of the

1
nearly 24 million noninstitutionalized children

6-11 years of age in the United States at the

time of the survey.

Statistical notes on the survey design, reliability of the data, and sampling and measurement error are shown in appendix I. Demographic and socioeconomic terms are defined in

appendix II.

SOURCES AND LIMITATIONS

OF DATA

Background information on the families of

these children that included family size, position

of mother in the household, and educational

level of the parents was obtained in a standardized interview by the U.S. Bureau of the Census

personnel during the selection of the sample to

be examined.

Medical history information–regarding prenatal care, complications during pregnancy,

place of birth of child, length of hospitalization

after birth, birthweight, twin status, handedness,

early developmental history, infant health

status, health history of neurological conditions,

and preschool educational experience—was obtained from a self-administered questionnaire

left in the home of the sample child by the

Census interviewer. The forms were completed

by the parent, usually the mother, and picked

up about 2 weeks later by the Health Examination Survey (HES) field representative. During

her visit to tlie home, the HES field representative reviewed the history and answered questions

that the parent may have had concerning that

form.

Information available from the birth certificate for more than 94 percent of the examined

children included birth order of the child,

birthplace of the mother, other children of this

mother now dead or stillborn, age of mother and

father at the time of this birth, pregnancy

complications, place of birth, birthweight, and

twin status, and that for about 60 percent of the

examined children included information on congenital malformation and birth injury.

Questions used from the household interview,

medical history, and birth certificate are shown

in appendix 111.

Data on congenital heart disease and neurological and musculoskeletal conditions present

and detected at the time of the survey were

obtained from the diagnostic impressions of the

survey pediatrician based on the findings of his

examination and on evaluation of the medical

history, as described previously.5

Estimates of the intellectual development

levels of these children were based on the

findings from the Vocabulary and Block Design

subtests of the Wechsler Intelligence Scale for

Children (WISC), which had been administered

during the psychological part of the examinaticu,

by the survey psychologists in a uniform manner, as previously described.6 The Vocabulary

and Block Design subtests of the WISC were

selected from the Verbal and Performance test

groups, respectively, since previous studies indicated that they were at least as good as any 2 of

the 12 subtests of the WISC in estimating Full

Scale intelligence from that test.6

A more thorough evaluation of the adequacy

of these two subtests of the WISC in the

estimation of Full Scale Intelligence Quotient

(IQ) of children 6-11 years of age was made by

Dr. Jane Mercer of the University of California

and the California State Department of Mental

Hygiene under contract with the National Center for Health Statistics. Findings from this

study among 1,310 children attending public

elementary schools in Riverside, California, in

1967-1968 showed that the dyad of subtests

used in the national survey produced predictions

of Full Scale IQ that were better or at least as

good as any other dyad of the WISC across all

three ethnic groups in the Riverside sample. The

correlation of Full Scale with the VocabularyBlock Design dyad determined either as a

multiple correlation from the two subtests or as

a simple correlation with the sum of the (scaled)

scores from the two subtests was +0.88.7

For convenience in this report, raw scores on

the Vocabulary and Block Design subtests for

children at each single year of age have been

converted to standard scores by setting the mean

obtained in this study at 100 and the standard

deviation at 15. The estimates for the Full Scale

deviation IQ from both subtests combined in

this report were derived by adding the standard

scores on the two subtests and again making a

scale transformation setting the mean at 100 and

standard deviation at 15. Except for the standardization within l-year rather than 4-month age

intervals and the use of standard scores rathef

2
than scaled scores, the methods used here are

identical to those described in the two previous

publications on WISC findings among children.G)8 This was done so that the standard

score values would be in units more nearly

comparable to those from the modified

Goodenough-Harris Drawing Test.

Intellectual maturity level estimates for these

children were based on findings from the modified Goodenough-Harris Drawing Test. As in the

previously published findings from thk test in

the national survey among children, raw scores

on the Man and Woman Scales have been

converted to standard scores with a scale transformation to a mean of 100 and standard

deviation of 15.9~10

These standard score or deviation IQ values

make possible the comparison of children of one

age with others of different ages, since these are

measures which theoretically remain invariant

with age on retest for a particular child unless

his actual test performance as compared with his

peers changes.

FINDINGS

Family Background

Previous reports from this national study have

considered the relationship of education of the

first parent (for 84 percent, this was the father

of the child) and of family income to the level

of intellectual development and intellectual maturity of U.S. children 6-11 years of ages ~10 A

strong positive association was found with each

socioeconomic factor. The degree of association

was substantially greater for intellectual development as measured by the short form of the

WISC than for intellectual maturity as measured

by the modified Goodenough-Harris Drawing

Test (HFD). On both tests the association was

slightly greater with parent education than with

family income. For the WISC the correlation or

degree of association (r) with education was

I-.48 and with income +.43. For the HFD test

the correlation with education was +.24 and

with income +.20. The associations were

stronger on the Vocabulary than on the Block

Design subtests of the WISC. When the effect of

income is held constant, the degree of association between parent education and intelligence

of these children is only slightly reduced because

of the strong relationship existing between

education and income (r = +.58).

In this report the relation of additional

aspects of family background to intelligence will

be considered, including educational level of

both parents, whether both parents are living in

the household, whether the mother was foreign

born, ages of both parents at the time these

children were born, other children in the family

not now living, family size, and age order of the

child in the family.

Parent education. –The strong positive relationship between education of the first parent in

the household and intelligence of the child is

clearly evident on each aspect of intelligence as

measured in this study. The mean standard score

or deviation IQ on the WISC increased consistently from 86 among those whose first parent

had less than 5 years of formal schooling to 108

among those whose parent had some college

education (table 1). The association was stronger

on the estimate of verbal intelligence as obtained

on the Vocabulary subtest of the WISC, where

mean standard scores increased from 84 among

children whose first parent had less than 5 years’

schooling to 110 among those whose parent had

some college education, than on the estimate of

intellectual performance from the Block Design

subtest of the WISC, where the mean standard

scores increased with parent’s educational level

from 90 to 107.

On the measure of intellectual maturity from

the modified Goodenough-Harris Drawing Test,

the consistent association of parent’s education

with intelligence of the child, although of a

lower order of magnitude, is clearly evident,

with the mean deviation IQ increasing from 90

among those whose first parent had the least

education to nearly 105 among those whose

parent had some college education. The pattern

is similar whether the child drew the figure of a

man or a woman on this test.

The pattern of association between education

of the second parent (for 86 percent of the

children, the mother) and intelligence of the

child is essentially identical to that found with

respect to the education of the child’s first

parent. The mean deviation IQ of these children

increased consistently on the WISC from 86 to

108 and on the HFD from 90 to 104, as the

education of the second parent increased from

less than 5 years to 13 years or more (table 1).

-..

3
.

The educational levels of the first and second

parent of the child tend to be similar (r= +.90).

Within the four broad educational groups considered here, for 60 percent both parents were

within the same group, for 18 percent the first

parent was one level advanced, for 17 percent

the second parent was one level advanced, while

for only 5 percent was there more than one level

difference between the two parents.

When the educational level of the first parent

is held constant and that of the second parent

allowed to vary, the positive pattern of association of the latter with the standard scores of the

child may be seen to persist consistently on the

Vocabulary subtests within each educational

group for the first parent, on the Block Design

for those whose first parent had 5 years or more

of schooling, and on the HFD when limited to

first parent with 5-12 years of formal schooling

(table 2 and figure 1).

The

father’s

pattern of association between the

and mother’s education and the intelligence of their children is essentially identical to

that indicated above for the first and second

parent of these children.

Relation to first parent. –For the majority of

these children (84 percent) the first-listed parent

in the household was the father, while for nearly

10 percent the mother was the only parent. Less

than 1 percent were living with unrelated foster

parents or guardians. Children whose father or

stepfather was in the household or whose

mother was the only parent generally obtained

higher mean scores than those living with grandparents, other relatives, or foster parents, as may

be seen in table A for findings from the HFD

test. The pattern is somewhat more consistent

for those drawing the Man than the Woman

figure, though the difference between the mean

sc;res” on th; two scales is negligible.

120

110

g

z

100

0

i=

a

s

u

n

z

<w

$

80

0

Under5

)

u-

..:”:4

A.

‘.

‘“

.

./

,,.~

./”*

EDUCATION OF FIRST PARENT (YEARS OF SCHOOLING COMPLETED)

I

.aas 5-S 9-12 13 or

than 5 iore

5.8 9-12

I

I

Less S-8 8-12 13 or

than5 m<re

t +

Lass 5.8 8-12 13—or

than5 more

13 andover

4’//“

./’

-.-. --.-.+

— WISCVocabulary

.-

--- WISCBlockDesign

---- HFD

EDUCATION OF SECOND PARENT (YEARS OF SCHOOLING COMPLETED)

I I

~esa 5-8 8.12 13 or

than5 more

‘igure 1. Mean daviation IQ on tha WISC Vocabulary and Block Dasign and the HFD tests for childran 6-11 years, by educational

attainment of first and aacond parent: United States, 1963-1965.
Table A. Number of children, percent of children, mean standard scores, and standard error of scores on the Goodenough-Harris

Drawing Test for children 6-11 yaars, by relation of first parent to child: United States, 1963-1965

Relation of first parent to child

Father . ., . .,, ,,, . . . . . . . . . . . . . . . . . . .

Mother . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Stepfather . . . . . . . . . . . . . . . . . . . . . . . . . .

Stepmother . . . . . . . . . . . . . . . . . . . . . . . . . .

Grandfather . . . . . . . . . . . . . . . . . . . . . . . . .

Grandmother . . . . . . . . . . . . . . . . . . . . . . . .

Otherrelativa . . . . . . . . . . . . . . . . . . . . . . . .

Unrelatedguardian . . . . . . . . . . . . . . . . . . . . .

Fosterparent . . . . . . . . . . . . . . . . . . . . . . . .

Numberof

children in

thousands

20,083

2,327

723

4

187

124

125

16

195

i Unreliable estimates, included only for completeness,

Birthplace ofmother. –Children6-ll years of

age whose mothers were born in a foreign

country obtained significantly lower mean

standard scores on the Vocabulary subtest of the

WISC than those whose mothers were born in

this country (87 compared with 100); whileon

the Block Design subtest and the HFD test, the

mean differences were small enough to bedueto

sampling variability alone (table 3andfigure 2).

These findings are similar among boys and girls

but are less consistent by age because of the

small number of children with foreign-born

mothers (3.4 percent). The poorer performance

for those with foreign-born mothers on the

Vocabulary subtest is most evident among the

youngest children at ages 6 and 7; while on the

Block Design subtest, this is apparent only

among those at age 6. Among older children, on

the WISC and the HFD tests, the mean differences were small enough to be due to sampling

variability alone.

Age of parents. –Mean deviation IQs of children 6-11 years of age in the United States

increased consistently with their mother’s age at

the time they were born, reaching their maximum values for those whose mothers had been

25-39 years. On the measure of intellectual

development (wISC), the increase was from a

mean standard score of 95 to 101; while on the

measure of intellectual maturity (HFD), mean

deviation IQ increased only 3 points from 98 to

slightly over 100 (table 4 and figure 3). Only on

Percent of

children

84.4

9.8

3.1

0.0

0.8

0.5

0.5

0.1

0.8

Goodenough-Harris Drawing Test

Mean standard scores

Man

Scale

101.0

97.8

100.2

‘ 99.4

94.8

92.1

90.5

‘ 93.0

96.6

Woman

Scale

101.0

98.6

96.6

97.5

92.4

92.3

‘113.1

95.2

Standard error

Man

Scale

0.64

1.06

1.61

] 70.27

2.46

5.66

3.45

‘ 65.77

2.11

Woman

Scale

0.48

0.88

1.77

4.42

3.70

3.50

‘ 56.98

3.93

the WISC were successive mean differences

between maternal age groups 10-19 years and

20-24 years large enough to be statistically

significant at the 5-percent probability level.

Only negligible variations in mean deviation

IQ of children over the maternal age span 25-39

years were evident; while among children whose

mothers had been 45 years or over, mean

deviation IQ’s on both measures declined to

their lowest point, 90 on the WISC and 91 on

the HFD. Because of the small number of

mothers in these older age groups, the mean

differences in deviation IQ of their children were

small enough to be due to sampling vanability

alone, i.e., not statistically significant at the

5-percent probability level. The decline was

slightly sharper on the Vocabulary than on the

Block Design subtest of the WISC and on the

Woman than on the Man Scale of the HFD.

The pattern of increase in mean deviation IQ

of children with paternal age at childbirth is

generally similar to that with maternal age on

both measures of intelligence. However, on the

WISC the mean values varied between 100 and

101 over the paternal age span of 25-44 years.

On both tests the decline in the older (paternal)

age groups was slightly less than that found with

maternal age and the differences between the

findings on the two subtests and two scales were

less marked.

Family size. –The intelligence of children 6-11

years of age in this country, both on the

5
WISCVocabulary WISC Block Design HFD

110-

P

11

It

#------ 4

.“

100- -

● #o*

/ ● ~

1

/

,P-”

g

p’

.’

~

4’

f

G If

; 90- -

I

0 ~ -.$’

z

$

,P”

z

,./’”

80- .~

+

o 1 1 I 1 I

6789101112 6789101112 6789101112

AGE IN YEARS

Figure 2. Mean deviation IQ on the WISC Vocabulary and Block Dasign and the HFD tests for children 6-11 years, by place of birth of

mother and age of child at time of survey: United Statas, 1963-1965.

‘o

— Native-born mother

--- Foreign-born mother

I

Mother

— Wlsc

100- -

--- HFD

,.0

d

95- -

90- -

10 20 30 40 50

I

Father

10 20 30 40 60

AGE OF PARENT AT TIME OF CHILO’S BIRTH

Figure 3. Mean deviation IQ on the short form of the Wechsler Intelligence Scale for Children (WISC) and on the modified

Goodenough-Harris Humeri Figure Drawing (HFD) tests for children 6-11 years of age, by aga of parants at time of child’s

birth: United States, 1963-1965.

6
measures of intellectual development (WISC)

and intellectual maturity (HFD), was found to

decrease consistently as the number of other

children in the household increased. Mean deviation IQs on the WISC decreased nearly 13

points, about 0.8 standard deviation, from 103

for children in families with one additional child

to 90 for those in families with seven or more

other children (table 5 and figure 4). On the

HFD test the decline was less rapid: mean

deviation IQ’s dropped less than 8 points, the

equivalent of 0.5 standard deviation, from the

maximum on that test of nearly 102 for children

in families with two other children to the

minimum of 94 for those in families with seven

or more other children. Mean differences in

performance cm the WISC were also large

enough to be statistically significant between

children in families with two-three and threefour other children and on the HFD between

those in families with two-three others.

On the subtests, the decrease was greatest on

the WISC Vocabulary subtest, a mean difference

of 17 standard score points, and least on the

other three, 8 points on the WISC Block Design

and Man Scale (HFD) and 7 points on the

Only children and those with one other child

in the family obtained larger mean standard

scores (4 points greater) on the Vocabulary than

on the Block Design subtest of the WISC, while

the reverse was found for those from larger

families of four or more other children. Only for

those in families with two or three other

children were the mean standard score differences so small they could easily be due to

sampling variability alone, i.e., not significant at

the 5-percent probability level. The findings on

the two scales of the HFD test with respect to

the family size were less consistent than those

on the WISC subtests, although children with

one other sibling rated significantly higher on

the Man than on the Woman Scale. Only

children and those with three or five siblings

obtained mean scores that weqe slightly greater

on the Man than on the Woman Scale, while in

other sized families, the reverse was found.

Children from families of no more than three

other children obtained higher mean standard

scores on the WISC than on the HFD tests, while

the reverse was found among those from larger

families. Mean differences were large enough to

be statistically significant onlv for families of

Woman Scale (HFD). ‘ “ one, five, and ~ix ;ther children.

105 - -

95- -

85 “-

.-’

,~

1 2 3 4 5 6

NUMESER OF CHILDREN UNDER 20 YEARS IN HOUSEHOLD

WISC Vocabulary

H

WISC Block Oesign

•1 HFO

7 8 or more

Figure 4. Mean deviation IQ on the WISC Vocabulary and Block Design and the modified HFD tests for children 6-11 years, by

numbar of children under 20 in the household: United States, 1963-1965.

7
The negative relationship of intelligence and

family size was stronger for boys than for girlsas

measured on the WISC, a mean decrease of 13

standard score points for boys (from a mean of

103 for those in families with two other children

to 90 for those in families with seven or more

other children) compared with 10 points for

girls (from a mean of 101 for those in families

with two other children to 91 for those in

families with seven or more other children). The

relationship and sex difference on the WISC

Vocabulary subtest findings were substantially

greater than those on the WISC Block Design.

The mean differences in deviation IQ with

respect to family size for both boys and girls

were lower and more nearly similar on the

measure of intellectual maturity (HFD) than on

that of intellectual development (WISC), 8

standard score points for boys and girls between

those with two other children and those with

seven or more other children in the family. The

pattern of relationship on the WISC Block

Design performance with family size was similar

to that on the HFD test, decreasing mean scores

with increasing family size of 10 points for both

boys and girls.

The positive relationship of education of the

first parent to the intelligence of the child is

found consistently across all family size groups

(table 6). Mean standard scores for children

whose first parent had some college education

exceeded those whose parent had less than 5

years’ schooling on both subtests of the WISC

and the HFD test, regardless of size of the

family. The mean differences between those in

the highest and lowest educational groups were

greatest on the Vocabulary subtest for children

from families with one or more other children

and ranged from 21 to 25 standard score points.

On the Vocabulary subtest for only children and

on the Block Design for those with or without

siblings, the magnitude of the mean differences

were about the equivalent of one standard

deviation, or 15-17 points. On the HFD test the

differences ranged from 10 to 15 points.

When controlled by educational level of the

first parent, a consistent pattern of inverse

relationship of family size to performance on

the Vocabulary subtest was found within each

parent educational level. The mean difference in

standard score points between those in the

smallest and largest sized families was less for

those in families where the first parent had some

college education (9 points) than for those

whose parent had 12 years of schooling or less

(13-15 points). Differences on the Block Design

subtest and the HFD test were substantially

smaller and less consistent with family size,

ranging from 2-6 standard score points across

the four parent education groups.

Children who had one or more older siblings

who had died or were stillborn, prior to the

birth of the child in this study, rated lower on

these measures of intelligence than did children

from families where this had not occurred (table

7). However, no significant or consistent trend

was found in relation to the number of such

nonliving older siblings.

Age order.–A significant relationship was

found between the age order (birth order) of the

children and their performance on the intelligence tests in this study. The mean deviation IQ

on both the measure of intellectual development

and that of intellectual maturity decreased

consistently with the decreasing age order of the

children, from 101 and 100 among those who

were oldest or only children in the family to 92

and 96, respectively, among those 6th or later in

age”order (table 8).

The relationship to age order was substantially stronger on the WISC than on the

HFD test. On the test parts, the association with

age order was also substantially stronger on the

Vocabulary than the Block Design of the WISC

and somewhat weaker on the Woman than on

the Man Scale of the HFD test. The mean

decreases on the Vocabulary, Block Design,

Man, and Woman test parts between those who

were first and those who were 6th or later were

12, 7, 5, and 2 standard score points, respectively. This pattern of relationship between

deviation IQ of these children and their age

order was generally similaramong both boys and

girls.

When controlled by family size (number of

children under 20 years in household), the

pattern of relationship of intelligence of chddren

to their age order in the family is essentially

eliminated. However, children from smaller

families (three or fewer children) rated higher on

these tests than did children from larger families,

irrespective of age order. The findings on the

8
two subtests of the WISC, where the pattern is

strongest, are shown in table 9.

As would be expected, irrespective of the age

order of the child, there was a consistent

increase in mean deviation IQ with increase in

educational level of the parent. The pattern,

which was simiksr with respect to the educational level of both first and second parent, was

shown on the WISC with the education of the

first parent and on the HFD test with the

education of the second parent (table 10).

Prenatal Care, Complications

The extent of prenatal care and complications

during pregnancy for the mothers of these

children age 6-11 years in the present national

study have been described in a previous re’

port.11 Some prenatal medical care had been

- obtained for more than 97 percent of the

mothers of these children. Medical problems or

complications during this pregnancy were reported for 13 percent, nearly all of whom had

consulted a doctor regarding the condition.

No relationship was found between the intelligence of these children and whether their

mothers had had complications during this

pregnancy. The mean deviation IQs on both

measures of intelligence were approximately 100

for the 13 percent whose mothers had such

problems indicated on the child’s birth certificate and for the 87 percent whose mothers did

not (table 11). Those whose mothers had obtained some prenataI care during this pregnancy

tested somewhat higher than those whose mothers did not, although the differences no longer

existed when the effect of parent education was

removed.

Condition of Child at Birth

Birthweight. –Available information from the

medical history given by the mother for the

children 6-11 years of age in this survey and

from the child’s own birth certificate showed

that nearly 3 percent had weighed less than 5

pounds at birth, 96 percent between 5 and 10

pounds, and the remaining 1 percent more than

10 pounds.l 1

Children who weighed between 5 and 10

pounds at birth rated higher on the two measures of intelligence than those who weighed less

than 5 pounds or more than 10 pounds (table 12

and figure 5). Mean differences on the WISC

were 5 and 4 standard score points, respectively,

for those who weighed less than 5 pounds or

more than 10 pounds. On the HFD test they

were nearly 4 and 2 standard score points,

respectively. Only on the measure of intellectual

maturity (HFD) was the mean difference between the scores for those essentially normal

weight at birth and the heavier babies small

enough to be due to sampling variability alone,

i.e., not statistically significant at the 5-percent

probability level.

When the more detailed birthweight data

from the birth certificate are used, the increase

in mean deviation IQ with weight (at birth) is

slow but consistent up to about 8 pounds, as

illustrated in table B for the WISC short-form

findings. For boys this increase was from 89

among those weighing less than 3 pounds 5

ounces at birth to over 102 for those weighing

between 7 pounds 12 ounces and 8 pounds 13

ounces. Girls showed a similar consistent but

100

95

90

0

r

1

■ “SC

m HFD

Under 5“” 5-1o Over 10

pounds pounds pounds

BIRTHWEIGHT

Figure 5. Mean deviation I Q on the short form of the Wfechs[er

Intelligence Scale for Children (WISC) and on the modified

Goodenough-Harris Human Figure Drawing (HFD) tests for

children 6-11 years of age, by weight at birth: United States,

1963-1965.

9
Table B. Mean deviation IQ and standard error of mean on the WISC short form, by birthweight and sex for children

6-11 years: United States, 1963-1965

Birthweight from birth certificate

Lessthan 3 pounds 5 ounces . . . . . . . .

3 pounds 5 ounces-4 pounds 6 ounces . .

4 pounds 7 ounces-5 pounds 8 ounces . .

5 pounds 9 ounces-6 pounds 10 ounces .

6 pounds 11 ounces-7 pounds 11 ounces

7 pounds 12 ounces-8 pounds 13 ounces

8 pounds 14 ounces-9 pounds 14 ofinces

9 pounds 15 ounces-11 pounds O ounce .

. . . . . . . . . . . . . . .

. . . . . . . . . . . . . . .

. . . . . . . . . . . . . . .

. . . . . . . . . . . . . . .

. . . . . . . . . . . . . . .

. . . . . . . . . . . . . . .

. . . . . . . . . . . . . . .

. . . . . . . . . . . . . . .

Deviation IQ

Zcizc

Mean

89.4

94.2

96.2

98.1

101.4

102.4

102.0

97.7

90.3

95.1

96.0

97.0

98.3

99.9

97.1

97.7

5-.PStandard error

L

*

1.50

2.70 1.80

1.40 1.00

0.90 0.70

0.70 0.60

0.90 0.70

1.30 1.50

1.70 4.10

slightly smaller gain in mean IQ, from 90 to 100 negligible proportion (O.1 percent) ambidexover the same birthweight span.

Length of hospitalization. –Those children

who were kept in the hospital 2 weeks or less

following their birth rated higher on both

measures of intelligence, on the average, than

those who were retained for over 2 weeks. Mean

differences were large enough to be statistically

significant on WISC (both Vocabulary and Block

Design) and on the Woman but not on the Man

Scale of the HFD test. The group who required

more than 2 weeks of hospital care at that time

(3 percent of the children) would have included

a large proportion of those born prematurely,

with birth injuries, congenitzd malformations,

and other medical problems. 11

Congenital malformations and birth injury.–

Chddren for whom a congenital malformation or

a birth injury was recorded and identified on the

birth certificate obtained somewhat lower mean

standard scores on the WISC (both Vocabulary

and Block Design), but not on the HFD test,

than those for whom no abnormality was noted

at birth. However, the proportion of children

who had such conditions was so small, i.e., less

than 2 percent, that the mean differences in

standard Score could easily be due to sampling

variability alone.

Handedness. –Among these children 6-11

years of age at the time of this study, approximately 11 percent were left handed and the

remaining 89 percent right handed, with a

trous.

Mean deviation IQs for right-handed children

were nearly identical to those for left-handed

children on both measures of intelligence and on

the four subtests or parts. The substantially

lower mean standard scores for the ambidextrous group are probably due to sampling

variability alone, i.e., not significant at the

5-percent level.

Twin status. –Twins were found to score

slightly but not significantly lower than the

single-born children on both the measure of

intellectual development and that of intellectual

maturity. Mean differences in deviation IQ

between nontwins and twins, as well as between

fraternal and identical twins, were small enough

to be due to sampling variability aIone since

only about 2 percent of these children were

twins.

Early Developmental History

Information on the early developmental history of these children 6-11 years of age at the

time of this study–including the age they first

started walking by themselves or speaking their

first real word and the relative speed with which

they learned to do th’mgs by themselves–have

been described and analyzed previously, ~2

Change f+otn breast ~eeding.-Children who

were reported by their mothers at the time of
the survey to have had no troubIe accepting the

change from breast feedingl 1 (91 percent of

those breast fed) generally rated slightly but not

significantly higher (mean difference of 2-3

standard score points) on the survey measures of

intellectual development and intellectual maturity than the remaining 9 percent of children who

were reported to have had some or a considerable problem switching to regular food (table

13).

Walking.-The intelligence of children who

first walked by themselves before the age of 1

year was, on the average, similar to that for

children who did not start walking until 12 to

18 months of age. Mean deviation IQ’s on the

measures of intellectual development and intellectual maturity were approximately 100 for

both those who started waking etily and those

who started at the more usual age (table 13 and

figure 6).

However, among children who did not walk

alone until after 18 months of age (nearIy 4

105

100

g

2

0

i= 95

~

>

:

3

z

90

85

0 I I

Wlsc

❑ HFD

fl

Under 12. 12-18 Over 1S

months months months

AGE CHILD FIRST WALKED ALONE

Figure 6. Mean deviation IQ on the short form of the Wechsler

- Intelligence Scale for Children (WISC) end on the modified

Goodenough-Harris Human Figure Drawing (HFD) tests for

children 6-11 years of age, by age child first walked

alone: United States, 1963-1965,

percent of the children), the mean deviation IQ

in both the WISC and the HFD test was

substantially lower—about 10 points less than

for those who walked alone by or before 18

months. Mean differences were statistically significant at the 1-percent probability level on

both tests and the four subtests or parts. The

mean difference or lag for this physically retarded group was slightly gz-eateron the Vocabulary subtest and Man Scale of the HFD test than

on the Block Design subtest and the Woman

Scale of the HFD test.(12 and 11 standard score

,points compared with 8 and 9).

Both boys and girls who started walking later

than usual were also significantly and similarly

retarded in mean deviation IQ on these intelligence tests.

Speech. –ChiIdren who did not speak their

first word until after 18 months of age (8

percent) were also significantly Iawer in intelligence as measured in this survey on either the

short form of the WISC or the modified HFD

test than those who started speaking earlier.

Their mean deviation IQ’s on both tests were 7

points behind those who started talking before

the age of 1 year and 5 points behind those who

began between 12 and 18 months of age (table

13 and figure 7). The differences in mean

standard scores among all three groups-those

who started talking early, at the more normal

age, or later–were too large to be due to

sampling variability alone, i.e., statistically significant at least at the 5-percent level. The

extent of retardation in deviation IQ among

those starting to speak later than usual was

slightly greater on the Vocabulary subtest than

on the other subtests. Among girls and boys

there was a similar pattern of lower intelligence

levels, on the average, among those starting to

talk later than usual.

Learning speed.–Mothers’ ratings of the speed

with which their children learned to do things

such - as eating or dressing by themselves is

generally consistent with their children’s later

performance at ages 6-11 years on these intelligence tests at the time of the survey. Those

children considered by their mothers as learning

faster than other children had significantly

higher mean deviation IQ’s on both intelligence

tests (scores of 103 on the WISC and 102 on the

HFD) than those whose learning speed was

11
g

z

g

105 =-

100 --

95 --

90 --

85 --

/

Wlsc

❑ HFD

I I

Under12 12-18

months months

+

months

AGE CHILD SPOKEFIRST REAL WORD

Fiaure 7. Mean deviation IQ on the short form of the Wechsler

- Intelligence Scale for Childran (WISC) and on the modified

Goodenough-Harris Human Figure Drawing (H FD) tasts for

children’ 6-11 years of aga, by age child spoka first real

word: Unitad States, 1963-1965.

considered average (scores of 99 on both tests).

The latter group, with average learning speed,

rated substantially higher on these tests than

those reported to have been slower in learning

than other children (mean scores of 89 on the

WISC and 91 on the HFD). These differentials

were found on

boys and girls.

all four &btests among both

Health at 1 Year

At the end of their first year of life, 91

percent of the children 6-11 years of age were

reported to have been in good health, nearly 8

percent in fair health, and nearly 2 percent in

poor health, according to the information given

by their mothers at the time of this survey, as

previously described. 11

Those children whose mothers reported them

to have been in good health at L year of age

rated significantly higher on both measures of

12

intelligence used in the study” than those considered in fair or poor health at that earlier

period. The pattern was similar on both tests:

the respective mean deviation IQ’s on the WISC

by infaht health status were 100, 97, and 93;

and on the HFD they were 100, 98, and 93

(table 13). The relationship of infant health

status to intelligence of children 6-11 years of

age was consistent among both boys and girls on

all four subtests.

Medical Problems

Medical hsktory of neurological problems. –The medical histories for the children

obtained from the mother just prior to their

examination indicated that 0.3 percent were

known to have epilepsy and 0.1 percent cerebral

palsy, as previously described.l 8

Those children reported to have cerebral palsy

tested more than 15 standard score points below

other children, on the average, on each of the

tests and subtests of intelligence used in the

survey (table 14), mean differences that on the

WISC and HFD were statistically significant at

the 5-percent probability level despite the low

prevalence of this condition. Those with a

history of epilepsy also had significantly lower

mean deviation IQ’s on these tests than other

children, but the mean differences were substantially smaller, 5 standard score points on the

WISC and 8 on the HFD.

Medical findings on examination. –From the

medical findings on physical examination at the

time of the survey, the prevalence of heart

conditions among U.S. children 6-11 Years was

estimated as 2.6 per 100 children and for

neuromuscular joint conditions as 3.6 per 100

(table 14 and figure 8). In addition 3.6 per 100

children were found to have some other type of

medical condition. These findings were based on

the medical history made available to the examining pediatrician and his own diagnostic

findings at the time of the survey exarnination.ls Information from the birth certificates

available for 60 percent of these children

showed that a congenital malformation with or

without a birth injury had been evident at birth

for 1.0 percent and that an additional 0.3

percent had a birth injury only. It should be

kept in mind that all three sources of information—the birth certificate, the medical his-
I I

Normal on examination

Congenital heart condition

Acquired heart condition

Cerebralpalsy and other cerebral problems

Mongolism ondlor mental retardation

Eye disorders

h4usculoskeletdjoint conditions only

I

o 20 40 60 80 100

PERCENTOF ALL CHILOREN

Figure 8, Percent of children 6-11 years of age, by specific finding on survey physical examination: United States, 1963-1965.

tory, and the examination–are subject to observer differences.

The examining pediatrician considered 80

percent of the heart conditions and 60 percent

of the neuromuscular joint conditions found or

identified on examination in the survey to have

been congenital.

Those children with congenital heart or

neuromuscular joint conditions found or identified on examination scored substantially lower

on both measures of intelligence used in the

survey than children without such physical

conditions and slightly below those whose heart

or neuromuscular joint condition was considered

to have been acquired. Mean deviation IQs for

those children with congenital heart conditions

were 5 standard score points below and those

with acquired heart condition about 3 points

below those without heart conditions on both

types of intelligence tests (WISC and HFD).

Those children with congenial neuromuscular

joint conditions had mean deviation IQs on the

HFD 8 standard score points below and on the

WISC nearly 6 standard score points below the

respective mean deviation IQs for children

without such conditions (table 14 and figure 9).

A further review of the specific type of

neurological joint conditions indicated that 0.5

percent of the children in this study had a

neurological condition identified as cerebral

palsy, other cerebral problem, or minimal cerebral dysfunction; 0.3 percent were identified on

examination as mongoloid and/or mentally retarded, 0.6 percent as having eye muscle disorders, and 2.2 percent as having only musculoskeletal joint conditions.

Findings from the measure of intellectual

development (WISC) used in the survey show

significantly lower mean deviation IQs for those

children with a condition identified by the

pediatrician as mongolism and/or mental retardation or as cerebral palsy, other cerebral

problem, or minimal cerebral dysfunction than

for those children with eye disorders or musculoskeletal joint conditions, as may be seen in

table 14.

Preschool Educational Experience

On the medical history obtained prior to the

survey examination of these children 6-11 years

of age the mother was asked whether the child

had attended kindergarten and/or nursery

school. Seventy percent of these children were

reported to have had such preschool educational

experience. The mean deviation IQs for children

with this experience was significantly greater

than for those without it, 7 standard score

13
‘orma’”nexam’na””n b~

Congemtal heart condwm

Acquwed heart condmon

Cerebral palsy and other cerebral problems

Mongollsm andlor mental retardatmn

Eye disorders

Musculoskeletal joint condwms only

o 75 80 85 90 95 100 105

MEAN DEVIATION IQ

Figure 9. Mean daviation IQ on the short form of the Wechsler Intelligence Scale for Children (WISC) for children 6-11 years of age,

by specific findings on survey physical examination: United States, 1963-1965.

points greater on the WISC and 4 points greater

on the HFD. The differential existed on both

the Vocabulary and Block Design subtests of the

WISC (mean differences of 8 and 6 standard

score points, respectively) but only on the

Woman Scale of the HFD, and on that to a lesser

extent (3 standard score points).

When considered in relation to the educational level of first parent for white and Negro

children, those with preschool educational experience consistently scored slightly higher, 2 to

6 standard score points on the average, on the

WISC Vocabulary and Block Design subtests and

on the HFD test than those without such

experience at each level of parent education

(table 15). The only exception was on the HFD

test for white children whose parents had

completed less than 5 years of formal schooling.

The relationship between educational level of

parent and deviation IQ of the child was

stronger on the WISC for white than for Negro

children but of approximately the same order of

magnitude on the HFD test for both racial

groups among children with and without some

preschool educational experience. Hence, for

children of both racial groups, preschool educational experience does seem to have a slight

positive influence on their standard scores on

these intelligence tests even when the effect of

the educational level of their first parent is held

constant.

DISCUSSION

Factors in the family background and early

developmental history of children considered in

this report in relation to their measured intelligence will themselves generally be influenced by

various aspects of both heredity and environment in varying degrees. The contributions of

both have been the subject of extensive study

for over half a century Since Binet’s early work

with intelligence testing.1A Studies of twins such

as that of Starr-Salapatekls have attempted to

estimate the proportion of variability in general

intelligence scores due to heredity and environment among the advantaged and disadvantaged.

However, this report is limited to national

estimates of the pattern of interrelation of the

factors considered with measured inteKlgence.

Comparisons are made insofar as possible with

previous relevant findings among children, al14
though almost without exception the previous effect which is essentially independent of the

studies have used tests of intelligence different effect of maternal age for fathers 45 years and

and not precisely comparable to those used in older consistent with results from the present

the present national survey. study. In particular, congenial malformations

were substantially more frequently found among

children with older fathers.

Family Background

The strong direct association between both

the intellectual development and intellectual

maturity of U.S. children 6-11 years of age and

the educational attainment of their parents

found in the present national study are consistent with previous findings among those groups

of children studied by Bayleyl 6 and Honzik.17

Younger children in the present study whose

mothers were foreign born, and hence would

have included a disproportionate number who

were bilingual, rated lower on the verbal but not

on the performance tests of intelligence used in

this study than did children of comparable age

of native-born mothers, consistent with the

findings from nearly 100 investigations in the

United States and other countries with respect

to intelligence test scores of younger bilingual

versus monolingual children. 18

The pattern of association between maternal

age and intellectual functioning of children from

the present study (lower deviation IQs for

children whose mothers were under 20 years and

those 40 years and over) is similar to but even

more pronounced than that found by Lobll 9 at

Johns Hopkins in his study of more than 3,000

births among mothers from middle and lower

sociocultural groups. He attributed the depressed IQ’s for children of younger mothers to

a number of biological and environmental factors including physiological and anatomic immaturity influencing maternal reproductive capacity and immaturity of maternal behavior

with respect to child-rearing practices. The

occurrence of mongolism and other anomalies of

the central nervous system he found to be

strongly related to advancing maternal age, with

over half of the reported cases of such conditions in his study being among children of

mothers 36 years and older.

With respect to the effect of paternal age on

intelligence of children, Newcombe and Tavendalez0 found, among their study group in

British Columbia, a significant paternal age

The negative relationship of family size, i.e.,

number of live siblings, to the intelligence of

U.S. children in the present study was more

pronounced on the verbal than on thel performance tests and stronger among those who~~

parents had no college education than those

whose parents did. This relationship is consistent

with -21,22 Bajema,23 Hig- findings of Anastasl,

gins,z4 and Nisbet.25 ~zG The relative differential in verbal and nonverbal development has

been attributed to different degrees of adult

contact provided in families of different size and

of different economic levels. However, studies of

Dawson27 and O’Hanlonz 8 among some 1,200

Glasgow children showed an even stronger negative or inverse relationship between intelligence

(Stanford-Binet tests) and family size when all

births, including stillbirths, were considered than

when limited to live siblings in the family. This

is also consistent with findings from the present

study where there is a more marked difference

in mean deviation IQ between single children

and those with one or more stillborn or deceased

siblings than with one or more live siblings.

The influence of ordinal birth position on

measured intelligence has been investigated for

some 100 years. Altus,z 9 in a review article,

cites analyses of persons in Who’s Who, Rhodes

Scholars, English Men of Science, and similar

select groups showing predominance of the first

born. Sir Francis Galton in the 1874 English

Men of Science suggested that through the law

of primogeniture the eldest son was likely to

become possessed of independent means and to

be able to follow his own tastes and inclinations.

Furthermore, he speculated that parents treated

an only child and a first born as a companion

and accorded him more responsibility than other

children. More recent findings of Chittenden et

al.30 showed differences between siblings on

grades and test scores that significantly favor the

first born. In the present national study, while a

significant inverse relationship was found between age order and performance on the intelligence tests used, the mean difference between

the first and second born was negligible.

15
Condition of Child at Birth

Birth weight. –The significantly lower mean

levels of both measured intellectual development

and intellectual maturity among U.S. children of

below and above normal birthweight than

among those of more normal birthweight (5-1 O

pounds) are consistent with findings from available previous studies. Babson et al.,s 1 in his

collaborative perinatal study among 4-year-old

Oregon children, found the mean IQ (StanfordBinet) of the oversized birthweight group to be

3.5 points below those of standard birthweight.

Various studies have been concerned with the

effect of prematurity or low bh-thweight on

physical and mental development. Weiner~ z

indicated in his review of available studies prior

to 1962 that of the 18 studies reported, only

one failed to find premature subjects at a

disadvantage in regard to IQ. More recent studies

of Weiner et al.38 ~3A have indicated that impairment (intellectual) in low birthweight infants is

largely due to associated measurable indexes of

minimal neurological involvement. Retarded

growth in premature babies has been attributed

in many cases to the effect of placental insufficiency. Yoshida et al.3s recently demonstrate ed

an altered pattern of energy metabolism in

leukocytes of premature (small for gestational

age) infants similar to that found in young

infants with severe postnatal protein-calorie malnutrition, thus lending support to the concept

that fetal growth retardation may be a manifestation of malnutrition Z%utero. On autopsy of a

group of small-for-gestational-age and normal

birthweight infants, Chase et al.3 G found the

cerebellum to be the area of the brain most

greatly affected by intrauterine underdevelopment.

Congenial malformations and birth injuries.–

Since the population under study excludes

imstitutio~alized children, the lack of a demonstrable association between measured intelligence and the presence or absence of a congenital malformation or injury identified at ~he time

of birth for U.S. children is not unexpected,

with the low prevalence of such conditions

recorded on the birth certificate. The 1970

report of a WHO Scientific Group on Genetic

Factors in Congenital Malformations,3 T in summarizing available research findings, indicates

that about 1 percent of all liveborn and stillborn

children have or will develop signs of a harmful

single-gene trait and that a further 1 percent

have chromosomal abnormalities, many of

which determine severe handicaps. In addition,

some 3-4 percent of all liveborn and stillborn

children have congenital malformations, as defined by the WHO group, although, as many of

these affect internal organs, they may not be

recognized until long after birth or at autopsy.

These WHO estimates are generally COI&kIIL

with those for U.S. children from the present

study. In a small proportion, the WHO report

indicated there is a known teratogenic agent—

e.g., maternal rubella, toxoplasmosis, or exposure in early intrauterine life to ionizing

radiation or to toxic agents or drugs. However,

the majority of such conditions have a genetic

component, and almost all have indirect evidence of an environmental component also.

Twin status.–National estimates from the

present study showed twins to have rated

slightly but not significantly lower, on the

average, than the single-born child on the verbal

component of the test of intellectual development (wISC-Vocabulary) and on the test of

intellectual maturity (HFD). On the performance component of intellectual development

(WISC-Block Design) twins did as well as nontwins.

These findings are somewhat less marked than

those of Mittler3 S and Record, McKeown, and

Edwardss g in England and Husen40 in Sweden.

Mittler, in his study of 4-year-old English children (200 twins and 100 singletons), found the

twins to be more retarded than the nontwins in

language development and also found some

indication of overall immaturity. Record,

McKeown, and Edwards, in their study of

Birmingham children (48,9 13 single born and

2,164 twins), showed twins to do less well on

the standard “eleven-plus” test of verbal reasoning than nontwins. They attributed this primarily to less frequent association of twins with

adults. Husen, in his study among 2,700 single

bores and 1,000 twins in Sweden, found that

twins did not do as well on achievement tests

and in school marks as the single born.

Much of the difference between findings from

the present study among U.S. children and those

from the English and Swedish studies is prob16
ably due to the lack of comparability of the

tests used.

Early Developmental History

Walking.–The strong association between delayed walking (starting after 18 months) and the

intellectual development and maturity of U.S.

children in the present study is consistent with

previous findings among various groups in the

population. Donoghue et al.41 found that only

11 percent of English children in a ward for the

mentally retarded had learned to walk before

the end of the second year compared with 95

percent of infants from a well-baby clinic who

walked unaided by age 10-14 months. Neligan

and PrudhamA z found from the Newcastle

Survey of Child Development that children later

excluded from normal school because of mental

defect, cerebral palsy, or deafness showed a

significant delay in walking unaided.

Speech. –The relationship between intelligence, as measured in this study, and the

retardation of speech development is nearly as

strong as that between intelligence and walking.

This also would have been expected since the

major causes of speech delay have generally been

found to be mental retardation, functional

(emotional), brain injury, and hearing 10SS.43)44

In the Newcastle Survey4 z Neligan and Prudham

also found that children later excluded from

normal school on account of mental defect,

cerebral palsy, or deafness showed a significant

delay in using sentences.

Children in the present national study with

articulation problems (8 percent of all children)

also had lower standard scores on these intelligence tests than those whose parent indicated

they had no trouble talking. This is consistent

with findings of Martyn, Sheehan, and Slutz45

for mentally retarded p’atients in a California

hospital where nearly one-third had articulation

disorders.

Medical Problems

Conditions affecting the development or functioning of the nervous system, primarily cerebral

palsy and epilepsy, have been found repeatedly

to be more prevalent among the mentally

handicapped ~ha.n among the general population.Az‘44 )46 In particular, Drillien et al.,46

in their studies of the mentally handicapped

children in Edinburgh, in and outside of institutions, found over one-half to have cerebral palsy

and about one-sixth to have epilepsy.

While the present study among U.S. children

is limited to the noninstitutional population and

hence excludes a substantial proportion of the

more severely mentally handicapped in this

country, the relation of these conditions to

measured intellectual development and maturity

is clearly apparent. Those U.S. children with a

history of cerebral palsy, though varying substantially in performance, obtained mean standard scores on both intelligence tests that were

more than 1 standard deviation below the mean

for all children (16 and 21 standard score points

lower, respectively); while those with a history

of epilepsy, who also varied widely in performance, as a group tested one-third to one-half a

standard deviation below the mean for all

children (5 standard score points on the WISC

and 8 on the HFD). Those with a history of

epilepsy, but not the cerebral palsied, were less

retarded on the Block Design than the Vocabulary subtest of the WISC.

For children with cerebral palsy and epilepsy,

the presence or extent of mental deficiency

would depend on the area of and degree to

which the brain was affected.

Cerebral palsy-the group of conditions affecting control of the motor system due to

lesions in various parts of the brain and occurring as a result of birth injury or prenatal

cerebral defect–is more frequently associated

with severe mental deficiency.

As summarized recently by Stores,47 previous

research on the cognitive function in children

with epilepsy (among whom proportionately

fewer appear to be mentally impaired) indicates

that among persons with epilepsy temporal lobe

lesions in the hemisphere dominant for speech

cause impairment of verbal abilities (including

defects of retention and learning of verbaI

material); while performance on tests of visuospatial or perceptual-motor abilities and of

memory for nonverbal material is impaired by

lesions of the temporal lobe in the nondominant

.hemisphere.4 8‘53

17
‘4

In contrast with patients with temporal lobe

attacks, those with “centrecephalic” epilepsy

have been shown to have no obvious memory

defect, but to be impaired on tests of sustained

attention.54

In further recent research on the comparative

performance of noninstitutionalized epileptic

and nonepileptic children, Green and HartlagesG

concluded that the reason epileptic children

scored below expectancy levels in school

achievement and language usage may be that

parental expectations tend to be lower for them

than if they were not epileptic. This hypothesis

would be consistent with the poorer performance among U.S. children shown on the Vocabulary than on the Block Design subtests of the

WISC from the present study.

Previous studies have suggested that children ‘

with significant congenital heart defects, especially of the cywotic type, may have delayed

motor development and a higher-than-expected

incidence of mental subnormalityys6-59 consistent with findings from the present study among

U.S. children. Findings from these earlier studies

were mixed with respect to the influence of

hemodynamic severity of the lesion, but several

suggest that environmental deprivation due to

physical incapacity may be a factor.

Preschool Experience

The slight advantage evident in this study on

the measures of intellectual development and

intellectual maturity of children who had some

preschool educational experience, such as that in

kindergarten or nursery school, over those who

had none is not inconsistent with findings from

several previous studies.

McHugh,G0 in his 1940 study of children

entering public school kindergarten in a small

town in New Jersey, found significant gains in

IQ score resulting from preschool experience

when the Stanford-Binet tests were given under

standard conditions and when the initial test was

given before any preschool experience. He

further concluded that since these gains

occurred so rapidly it was more likely they were

due to better adjustment of the testee in the test

situation than any real growth in intellectual

capacity.

Earlier studies ofWellman61 at the University

of Iowa Child Welfare Research Station found

that length of preschool experience beyond 1

year bears a direct relation to the amount of

gain in intellectual capacity.

In a number of reports from established child

research centers throughout the United States—

including those of Anderson,G Z Bayley,63 ~64

Bird,G5 Frandsen and Barlow,G6 Goodenough

and Maurer,6T Lamson,68 Olson and Hughes,6g

and VoasT0—the investigators were unable to

conclude from the results of their researches

that preschool experience has any appreciable

effect upon the IQ.

A subsequent study by Wellman and McCandless71 at the Iowa Child Welfare Research

Station found evidence suggesting that teacher

contacts at the station preschools play a definite

role in the verbal aspects of mental development, particularly of children in their first year

of preschool experience, but that verbal aspects

of intelligence are not the aspects in which

preschool is most stimulating to IQ change.

More recently Cicarelli et al.,7z in their

evaluation of the effect of the Head Start

programs, found slight but statistically significant superiority of full-year Head Start children

on certain measures of cognitive development.

In their review of the existing evaluative studies,

they also found that these preschool curricula

achieve little unless they focus on language and

number concepts.

SUMMARY

This report contains national estimates of the

prevalence of selected congenital or other early

developmental health problems and describes

the relationship of selected aspects of family

background, infant health status, and early

developmental history to the intellectual development and maturity of noninstitutionalized

children 6-11 years of age in the United States,

based on findings from the National Health

Examination Survey of 1963-1965. For this

national study, the probability sample of 7,417

children selected was representative, and the

7,119 (96 percent) examined were closely representative of the 24 million noninstitutionalized

children 6-11 years of age at that time.

The measures of intellectual development

used were the short form of the WISC (Vocabulary and Block Design) and the modified HFD

tests.
The principal findings from this study are that

●

●

●

●

The relationship between intellectual development or intellectual maturity of children

and the academic achievement of their

second parent, or mother, was as strong as

that previously found for this group with

the educational level of their first parent,

or father.

Children 6-11 years of age whose mothers

were foreign born generally did as well as

children whose mothers were natives of this

country on the tests of intellectual development and intellectual maturity used in this

study except for younger children on the

verbal component (wISC-Vocabulary).

Mean deviation IQ scores of these children

6-11 years of age increased with the age of

their mother and their father at the time of

their birth to a maximum at 25-39 years

for maternal age and 25-44 for paternal

age. Those whose parents had been older,

40 years or more for the mother and 45

years or older for the father, showed lower

mean scores than those whose parents had

been younger at the time these children

were born.

The intelligence of children (mean deviation IQ) on both measures used in this

study was found to decrease consistently as

the number of other live children in the

family increased. When controlled on educational level of the first parent, that

pattern of indirect association with family

size on the WISC Vocabulary subtest persisted but was less marked or consistent on

●

●

●

●

●

either the WISC Block Design or the

modified HFD.

Children who were of relatively normal

weight at birth, 5-10 pounds, rated significantly higher on both measures of intelligence used in this study than those who

weighed under 5 pounds or more than 10

pounds.

Twins were found to score slightly but not

significantly lower than single-born children on both measures of intelligence.

Children whose walking or speech was

retarded beyond 18 months of age showed

significantly lower mean deviation IQ’s on

both measures of intelligence.

Prevalence estimates for medical conditions

specifically identified on examination or

history for these noninstitutionalized U.S.

children 6-11 years of age including epilepsy, cerebral palsy, mongolism, eyemuscle disorders, and heart and musculoskeletal joint conditions were obtained.

Those children with such medical conditions tended to show significantly lower

mean deviation IQ scores than children

without these problems.

Children with some preschool educational

experience—i.e., who-had attended kindergarten or nursery school–generally showed

some advantage in deviation IQ scores over

those without such preschool training even

when the effect of the educational attainment of their parent(s) was held constant.

Comparisons with relevant findings from previous available studies are included.

19
REFERENCES

1Nationrd Center for Health Statistics: Origin, program, and

operation of the U.S. National Health Survey. Vital and Health

Statistics. PHS Pub. No. 1000-Senes l-No. 1. Public Health

Service. Washington. U.S. Government Printing Office, Apr.

1965.

2Nationaf Center for Health Statistics: ‘ Plan and initial

program of the Health Examination Survey. Vital and Health

Stattktics. PHS Pub. No. 1000-Senes l-No. 4. Public Herdth

Service. Washington. U.S. Government Printing Office, July

1965.

3National Center for Health Statistics: Cycle I of the Health

Examination Survey: Sample and response, United States,

1960-1962. Vital and Health Statistics. PHS Pub. No. 1000-

Series 1l-No. 1. Public Health Service. Washington. U.S. GovernmentPrinting Office, Apr. 1964.

4National Center for Health Statistics: Plan, operation, and

response results of a program of children’s examinations. Vital

and Health Statistics. PHS Pub. No. 1000-Series 1-No. 5. Public

Health Service. Washington. U.S. Government Printing Office,

Oct. 1967.

5National Center for Health Statistics: Examination and

health hktory findings among children and youth, 6-17 years,

United States. Vital and Health Statistics. Series 11, No. 129.

DHEW Pub. No. (HRA) 74-1611. Herdth Resources Administration. Washington. U.S. Government Printing OffIce, Nov. 1973.

6National Center for Health Statistics: Intellectual development of chddren as measured by the Wechsler Intelligence Scale,

United States. Vital and Health Statistics. Series 11, No. 107.

DHEW Pub. No. (HSM) 72-1004. Health Services and Mental

Health Administration. Washington. U.S. Government Ptinting

Office, Aug. 1971.

7National Center for Health Statistics: Subtest estimates of

the WISC full scale IQ’s for chddren. Vital and Health Statistics.

Series 2, No. 47. DHEW Pub. No. (HSM) 72-1047. Health

Services and Mental Health Administration. Washington. U.S.

Government Printing Office, Mar. 1972.

8National center for Health Statistics: Intellectual development of children by demographic and socioeconomic factors,

United States.’ Vital and Health Statktics. Series 11, No. 110.

DHEW Pub. No. (HSM) 72-1012. Health Services and Mental

Health Admhistration. Washington. U.S. Government Printing

Office, Dec. 1971.

‘Nationaf Center for Health Statistics: Intellectual maturity

of children as measured by the Goodenough-Harns Drawing

Test, United States. Vital and Health Statistics. Series 11, No.

105. DHEW Pub. No. (HSM) 73-1267. Health Services and

Mental Herdth Adminktration. Washington. U.S. Government

Printing Office, Dec. 1970.

1‘National Center for Health Statistics: Intellectual maturity

of children: Demographic and socioeconomic factors, United

States. Vital and Health Statistics. Series 11, No. 116. DHEW

Pub. No. (HSM) 72-1059. Health Services and Mental Health

Administration. Washington. U.S. Government Printing Office,

June~972.

~1National Center for Health Statistics Prenatal-postnatal

health needs and medical care of children, United States. Vital

and Health Statistics. Series 11, No. 125. DHEW Pub. No. (HSM)

73-1607. Health Services and Mental Herdth Adminktration.

Washington. U.S. Government Printing Office, Apr. 1973.

12National Center for Health Statistics: Parent ratings of

behavioral patterns of children, United States. Vital and Health

Statistics. Series 11, No. 108. DHEW Pub. No. (HSM) 72-1010.

Health Services and Mental Health Administration. Washington.

U.S. Government Printing Office, Nov. 1971.

13National Center for Health Statistics: Examination and

health history findings among children and youth 6-17 years,

United States. Vital and Health Statistics. Series 11, No. 129.

DHEW Pub. No. (HRA) 74-1611. Hesdth Resources Admir&

tration. Washington. U.S. Government Printing Office, Nov.

1973.

14Binet, A., and Simon, T.: The Development of Intelligence

in Chifdren, (Trans. by E. S. Kite) Baltimore. Williams and

Wilkins, 1916.

15Scarr-Salapatek, S.: Race, social class, and IQ. Science

i

174 4016):1285-1295, Dec. 24, 1971.

6Bay1ey, N.: Some incm~ing pruent-child similarities d~g

the owth of chddren. JEduc.PsychoL 45( 1):1-21, Jan. 1954.

l%Honzik, M. P.: Developmental studies of parent-child

resemblance in intelligence. Child Dew 28(2):215-228, June

1957.

18Arsenian, S.: BKmgualism in the post-war world. l%Ychol.BulL 42(2):65-86, Feb. 1945.

19Lobl, M., Welcher, D. W., and Mellits, E. D.: Maternal age

and intellectual functioning of offspring, ]oh.s Hopkins MerLJ.

128(6):347-361, June 1971.

20Newcombe, H. B., and Tavendale, O. G.: Effects of

father’s age on the risk of child handicap or death. Am.J.Hum.

Genet. 17(2):163-178, Mar. 1965.

21An~~si, A.: Intelligence and family size. PsychoLBulL

53(3): 187-209, May 1956.

22Amstasi, A.: Differentiating effect of intelligence and

sociaf status. Eugenics Q 6(2):84-91, June 1959.

23 Baje~, C.: Relation of fertility to occupational statu% IQ>

educational attainment, and size of family of origin: A follow-up

study of a male Kalamazoo public school population. Eugenics

Q 15(3):198-203, Sept. 1968.

24Higgins, J. V., Reed, E. W., and Reed, S. C.: Intelligence

and family size: A paradox resolved. Eugenics Q 9(2):84-90,

June 1962.

25Nisbet, J. D.: Family environment and intelligence. Eugenics Rev. 45(1):31-40, Apr. 1953.

20
26Nisbet, J. D., and Entwistle, N. J.: Intelligence and family

size 1949-1965. Br.&?MrJc.PsychoL 37(2):188-193, June 1967.

~7Dawson, S.: Intelligence and fertiKty. Br.JPsychoL

$’

23(1 .42-51, Ju1Y 1932.

2 O’Hanlon, G. S. A.: An investigation into the relationship

bet we en fertility and intelligence. Br.J.Educ.PsychoL

10(3 .196-211, NOV. 1940.

2kAltu~, W. D.: Birth order and its sequelae. Science.

4

151 3706):44-49, Jan. 7, 1966.

‘Chittenden, E. A., et al.: School achievement of first- and

second-born siblings. Child Dev. 39(4):1223-1228, Dec. 1968.

31 Babson, S. G., Henderson, N., and Clark, W. M.: The

preschool intelligence of oversized newborns. Pedtitrics

44(4 :5.36-538, Oct. 1969.

i 3 Wiener, G.: Psychologic correlates of premature birth: A

review. J.Nerv.Men.Dis. 134(2):129-144, Feb. 1962.

33 Wiener, G., et al.: Correlates of low birth weight:

Psychological status at six to seven years of age. Ped@-z”cs

35(3):434-444, Mar. 1965.

34Wlener, G., et al.: Comelates of low birth weight:

Psychological status at eight to ten years of age. Pediatr. Res.

2(2!#0-118’Mm. 1968. Yoshida, T., et al.: Human fetal growth retardation: ~1.

Energy metabolism in leukocytes. Pediatrics 50(4):559-567, Oct.

1972.

36Chase, H. P., et al.: Alterations in human brain biochemistry following intrauterine growth retardation. Pediatrics

\

50(3 .403s411, Sept. 1972.

3 World Health Organization: Genetic factors in congenital

malformations. Report of a WHO Scientific Group. TechRep.

Ser. WloLHlth.Org., No. 438. Geneva, 1970.

38Mittler, P.: Biological and sociaf aspects of language

development in twins. Dev.Med.Child NeuroL 12(6):741-757,

Dec. 1970.

39 Record, R. G., McKeown, T., and Edwards, J. H.: An

investigation of the difference in measured inte~lgence between

twins and single births. Ann. Hum. Genet. 34(1):11-20, July

1970.

40 Husen, T.: Abilities of twins. Stand.J.PsychoL

1(3):125-135, 1960.

41 Donoghue, E. C., et al.: Some factors affecting age of

walking in a mentally retarded population. DewMed.Chitd

Neurol. 12(6):781-792, 1970.

42 Neligan, G., and Prudham, D.: Potential value of four early

developmental milestones in screening children for increased risk

of later retardation. Dev.Med. Child NeuroL 11(4) :423-431, Aug.

1969.

43vm Riper, C.: Speech Cowection; Principles and Methods,

4th ed. Englewood Cliffs, N.J. Prentice-Hall, 1963.

44 Fiedler, M. F., et al.: A speech screening procedure with

three-year-old children. Pediatrics 48(2) :268-276, Aug. 1971.

45 Martyn, M. M., Sheehan, J., and Slutz, K.: Incidence of

stuttering and other speech disorders among the retarded.

Am. .Ment.Defic. 74(2):206-211, Sept. 1969.

=/6Dnllien, C. M., Jatneson, S., and Wilkinson, E. M.: Studies

in mental handicap. Part I: Prevalence and distribution by

clinical type and severity of defect. Arch. Dis.Child.

41(219):528-538, Oct. 1966.

47 Stores, G.: Cognitive function in chifdren with epifepsy.

Dev.Med.Child Neurol. 13(3) :390-393, June 1971.

48Milner, B,: Intellectual function of the temporal lobes.

PsychoLBulL 51(1) :42-62, Jan. 1954.

49Meyer, V., and Yates, A. J.: Intellectual changes foflowing

temporaf lobectomy for psychomotor epilepsy. J. NeuroL

Neurosurg.Psychiat. 18(1):44-52, Feb. 1955.

50 Quadfasel, A. F., and Pruyser, P. W.: Cognitive deficit in

patients with psychomotor epilepsy. Epilepsia 4:80-90, Nov.

1955.

5 lMilner, B.: Psychological defects produced by temporaf

lobe excision. Proc.Assn.Nerv.Ment.Dis. 36:244-257, 1958.

52Meyer, V.: Cognitive changes following temporal lobectomy for relief of temporaf lobe epilepsy. Arck.Neurol.

81(3):299-309, Mar. 1959.

53 Blakemore, C. B., and Falconer, M. A.: Long-term effects

of anterior temporal lobectomy on certain cognitive functions.

J.NeuroLNeurosurg.Psychirt. 30(4) :364-367, Aug. 1967.

5%4iiky, A. F., et al.: A comparison of the psychological

test performance of patients with focal and nonfocal epilepsy.

Exp.NeuroL 2(1):75-89, Feb. 1960.

55Green, J, B., and Hartlage, L. C.: Comparative performance of epileptic and nonepileptic children and adolescents.

Dis.Nerv.Syst. 32(6):418-421, June 1971.

56 Campbell, M., and Reynolds, G.: The physical and mental

development of children with congenital heart disease. Arck.Dis.

ChiU 24(120):294-302, Dec. 1949.

57Tyler, H. R., and Clark, D. B.: Incidence of neurological

complications in congenital heart disease. AMA Arck.NeuroL

Psychrizt. 77(1) :17-22, Jan. 1957.

58Linde, L. M., Rasof, B., and Dunn, O. J.: Mental

development in congenital heart disease. J.Pediatr.

71(2): 198-203, Aug. 1967.

59 Feldt, R. H., et al.: Chddren with congenital heart disease.

Am.J.Dis.Child. 117(3):281-287, Mar. 1969.

6%cHugh, G.: Changes in I.Q. at the pubfic school

kindergarten level. PsychoLMonogr. 55(2):1-34, 1943.

61Wellman, B. L.: Some new bases for interpretation of the

IQ. J. Gerset.PsychoL 41(1):116-126, Sept. 1932.

62Andemon, L. D.: A longitudinal study of the effects of

nursery-school training on successive intelligence-test ratings.

39th Yearbook, NatlSoc. Study Educ. 11:3-10, 1940.

63 Bayley, N.: Mentaf growth in young children. 39th

Yearbook NatLSoc. Study Educ. II: 11-47, 1940.

64Bayley, N.: Factors influencing the growth of intelligence

in young children. 39th Yearbook NatLSoc. Study Educ. 11:

49-79.1940.

65 Bird, G. E.: The effect of nursery-school attendance upon

mentrd growth of children. 39th Yearbook Natl.Soc. Study

Educ. 11:81-84, 1940.

66 Frmdsen, A., ad Bmlow, F. p.: Influence of the n~se~

school on mental growth. 39th Yearbook NatlSoc. Study Educ.

11:143-148.1940.

67Goodenougb, F. L., and Maurer, K. M.: The mental

development of nursery-school children compzred with that of

non-nursery-school children 39th Yearbook Natl.Soc. Study

Educ. 11:161-178, 1940.

68Lamson, E. A.: A follow-up study of a group of

nursery-school children. 39th Yearbook NatLSoc. Study Educ.

11:231-236, 1940.

6901son, W. c., md Hughes, B. O.: Subsequent growth of

children with and witbout nursery-school experience. 39th

Yearbook Natl.Soc. Study Educ. 11:237-244, 1940.

21
70Voas, W. H.: Does attendance at the Winnetka Nursery and effective development. Vol. I. Bladensburg, Maryland.

School tend to raise the IQ? 39tlz Yearbook Natl.Soc. Study Westinghouse Learning Corp., June 1969.

Educ. 11:363-376, 1940. 73National Center for Health Statistics: Sample design and

71Welbnan, B. L., and McCandless, B. R.: Factors associated

with Binet IQ changes of preschool children. PsychoLMonogr.

estimation procedures for a national health examination survey

60(2):1-29, 1946. of children. Vital and Health Stati&s. Series 2-No. 43. DHEW

72Cicarelli, V., et al.: The impact of Head Start: An Pub. No. (HRA) 74-1005. Health Resources Administration.

evaluation of the effects of Head Start on chddren’s cognitive Washington. U.S. Government Printing Office, Aug. 1973.

22
LIST OF DETAILED TABLES

Table 1,

2,

3.

4,

5,

6.

7.

8.

9.

10.

11.

Mean deviation IQ and standard error of the mean on the short form of the Wechsler Intelligence Scale for

Children (WISC) and tha modified Goodenough-Harris Human Figure Drawing (HFD) tests for and numbar and

percent distribution of children 6-11 years of age, by educational attainment of mother and of father: United

Statas,1963-1965 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Mean deviation IQ and standard error of the mean on the short form of the Wechsler Intelligence Scale for

Children (WISC) and the modified Goodenough-Harris Human Figure Drawing (HFD) tasts for and number and

parcent distribution of children 6-11 years of age, by educational attainment of mother and of father: United

States, 1963-1965 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..,,

Mean deviation IQ and standard error of the mean on the short form of tha Wechsler Intelligence Scale for

Children (WISC) and the modified Goodenough-Harris Human Figure Drawing (HFD) tests for and percent

distribution ofchildren 6-11 years ofage, byplace of birth ofmother, aga, andsex: Unitad States, 1963-1965 . .

Mean daviation IQ and standard error of the mean on the short form of the Wechsler Intelligence Scale for

Children (WISC) and the modified Goodenough-Harris Human Figure Drawing (HFD) tests for and percent

distribution of children 6-11 years of aga, byageof mother andoffather atthetime of thechild's birth: United

States,1963-1965 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Mean deviation IQ and standard error of the mean on the short form of the Wechsler Intelligence Scale for

Children (WISC) and the modified Goodenough-Harris Human Figure Drawing (HFD) tests for and number and

percent distribution ofchildren 6-11 years of aW, bynumber ofchildren under 20years inthehousehold andwx

ofchild: UnitedStates, 1963-1965 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Mean deviation lQ and standard error of the mean on the WISC Vocabulary and Block Dasignand the modified

HFDtests for and percantof children 6-11 years ofage, byeducational attainment of first parent and numberof

children under 20years in the household: United States, 1963-1965 . . . . . . . . . . . . . . . . . . . . . . . . . .

Mean deviation lQ and standard error of the mean on tha short form of the Wechsler Intelligence %-ale for

Children (WISC) and the modified Goodenough-Harris Human Figure Drawing (HFD) tests for and parcent

distribution of chiidren 6-11 years of age, by numbarof deceased siblings (born dead orwhodied later) :United

States,1963-1965 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Mean deviation IQ and standard error of the mean on the short form of the Wechsler Intelligence Scale for

Childran (WISC) and the modified Goodanough-Harris Human Figure Drawing (HFD) tests for and number and

parcent distribution ofchildren 6-11 years, byageorder of thechild in the family: United States, 1963-1965 . .

Mean deviation lQ and standard error of the mean on the WISC Vocabulary and Block Design tests for children

6-11 years of age, by aga order of child in family and number of children under 20 years in the

household: UnitedStates, 1963-1965 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Mean deviation lQandstandard error of themean byageordar ofchild in family andeducation ofsecond parent

on the modified HFD test and by age order of child in family and education of first parant on the WISC

Vocabulary and Block Design tests: United States, 1963-1965 . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Maan deviation IQ and standard error of the maan on the short form of the Wechsler Intelligence Scale for

Children (WISC)and themodified Goodenough-Harris Human Figure Drawing (H FD)tests forchildren 6-11 yaars

of age, by presance or absence of medical complications of mother during pragnancy and by education of the

second parentontheWISC: UnitedStates, 1963-1965 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Page

25

26

27

27

28

28

29

28

30

30

31

23
LIST OF DETAILED TABLES–Con.

Page

Table 12. Mean deviation IQ and standard error of the mean on the short form of the Wechsler intelligence Scale for

Children (WISC) and the modified Goodenough-Harris Human Figure Drawing (HFD) tests for and number and

percent distribution of childran 6-11 years of age, by birthweight, length of baby’s stay in hospital aftar birth,

congenital malformations and birth injuries shown on birth certificate, handedness, and twin status: United

Statas,1963-1965 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

13, Mam deviation lQ and standard error of the mean on the short form of the Wechsler Intelligence Scale for

children (WISC) and the modified Goodenough-Harris Human Figura Drawing (HFD) tests for and percent

distribution of children 6-11 years of age, by critical aspects of aarly developmental history: United States,

1663-1965 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

14. Mean deviation lQ and standard error of the mean on the short form of the Wechsler Intalligenca Scala for

Children (WISC) and the modifiad Goodenough-Harris Human Figure Drawing (HFD)tests forand percent of

children 6-11 years of age, by findings of congenital and acquired chronic conditions on survey examination:

UnitedStates, 1963-1965, . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

1!5. Mean deviation lQ and standard arrorof the mean on the WISC Vocabulary and Block Design andthemodifiad

HFD tasts for children 6-11 yaars of age, by race, kindergarten or nursery school experience, and educational

attainmantoffirstparent: UnitedStates, 1963-1965 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

24
Tablel. Mean deviation lQandstandard error of themean ontheshoR formoftha Wechsler intelligence Smlefor Children (WlSC)

and the modified Goodenough-Harris Humeri Figure Drawing (HFD)tests forandnumber andpercent distribution ofchildren6-ll

yearn of age, by educational attainment of mother and of father: United States, 1963-1965

Education of father and

of mother

Father (lst parent)

Lassthan5years . . . . . . . . . .

6-Byears . . . . . . . . . . . . . . . .

9-12years . . . . . . . . . . . . . . .

13years or more . . . . . . . . . . .

Mother (2d parent)

Lessthan 5 years . . . . . . . . . .

5-8years ..,.........,.. .

9.12 years , . , . . . . . . . . . . . .

13yaarsormore . . . . . . . . . . .

Father (lst parent)

Lessthan5years . . . . . . . . . .

6-6years . . . . . . . . . . . . . . . .

9.12 years . . . . . . . . . . . . . . .

13years ormore . . . . . . . . . . .

Mother (2d parent~

Lessthan5years . . . . . . . . . .

5-6years . . . . . . . . . . . . . . . .

9.12years . . . . . . . . . . . . . . .

13yearsor more . . . ..m . . . . .

I

Wlsc IHFD

Combined Vocabulary Block I

Combined Man

Design Scale

86.1

93.9

100.2

107.7

86.0

92.5

100.9

108.3

0.86

0.76

0.30

0.52

1.30

0.72

0.32

0.85

83.8

93.6

101.0

108.7

82.9

91.4

101.8

110.3

Mean deviation IQ

68.5

95.4

100.6

107.1

90.0

94.7

101.3

107.7

90.4

96.8

100.0

104.5

88.6

96.1

100.6

103.7

Standard error of mean

1.52

0.83

0.49

0.58

2.10

0.98

L-0.43

0.77

0.51

0.75

0.31

0.71

0.92

0.58

0.43

1.08

91.0

97.9

101.1

105.0

91.0

97.4

101.6

104.1

L

0.85 1.34

0.68 0.86

0.38 0.48

0.53 0.61

1.27 1.89

0.65 0.91

0.48 0.55 ~

0.60 0.72

Woman

Scale

92.5

97.6

100.9

105.8

90.3

97.0

101.4

105.1

1.54

0.54

0.41

0.61

1.77

0.86

0.51

0.61

Number of

children

in thousands

1,419

4,116

10,I8?I

4,256

839

3,314

13,070

3,232

...

---

...

...

...

...

-..

---

Percent

of

:hildren

7.1

20.6

51.0

21.3

4.1

16.2

63.9

15.8

...

---

...

---

..-

---

..-

..-

25
Table2. Mean deviation lQandstandard error of thamean onthashoR form of the Wechsler lntelliWnce Smlefor Children (WISC) and the modified

Goodenough-Harris Human Figure Drawing (HFD) tests for and number and percent distribution of children 6-11 years of age, by aducetional

attainment of mother and of father: United States, 1963-1965

Education of father and

of mother

Father, under 5 years

Mother:

Under 5yaars . . . . . . .

5-8years . . . . . . . . . .

9-12 years . . . . . . . . .

13yearsorm0re . . . . .

Father, 5-8 years

Mother:

Under 5 years . . . . . . .

5-8years . . . . . . . . . .

9-12years . . . . . . . . .

13years0r more . . . . .

Father, 9-12 years

Mother:

Under 5 years . . . . . . .

5-8years . . . . . . . . . .

9-12 years . . . . . . . . .

13years or more . . . . .

Father, 13 yaars or more

Mother:

Under 5years . . . . . . .

5-8years . . . . . . . . . .

9-12 years . . . . . . . . .

13 years or more . . . . .

Wlsc !HFD

II 1 11 I

Combined I

Vocabulary I

810ck I

Man

Combined

Woman

Design Scale Scale

84.7

87.1

86.1

95.6

88.0

92.3

96.7

101.3

89.3

96.2

101.3

104.4

103.8

105.6

110.2

81.0

64.6

85.5

102.6

86.6

91.9

96.7

100.7

86.3

94.8

102.3

105.9

104.3

107.3

112.6

Mean deviation IQ

88.3

90.7

87.9

90.5

90.4

93.8

88.0

103.2

93.3

98.6

101,6

104.2

104.5

105.2

108.3

89.4

92.0

90.3

94.8

90.6

95.9

98.0

104.3

91.6

96.6

100.6

100.7

104.5

104.4

104.8

89.6

91.6

93.1

97.0

91.3

97.6

98.8

104.8

96.7

99.9

101.7

101.0

I 06.6

104.7

I 05.3

91.9

96.0

90.0

91.6

96.4

98.9

105.2

88.7

99.5

101.2

103.2

102.2

105.8

105.9

Standard error of mean

1.98

0.74

1.28

67.62

2.26

0.96

0.70

2.79

1.49

1.02

0.30

0.93

2.62

0.48

1.02

2.36

1.68

1.08

67.06

2.78

0.80

0.94

1.80

2.84

1.19

0.47

0.86

2.67

0.72

0.76

Number of

children

in thousands

502

846

284

7

193

1,531

2,250

140

132

978

8,223

856

94

2,124

2,039

‘arcent

of

hildren

35.4

45.5

18.6

0.5

4.7

37.2

54.7

3.4

1.3

9.6

80.7

6.4

2.2

49.9

47.9

26
7’ablo3, Mmndevimlm 10andstandard error .fthemeon onthe$horl form of the Wechs!er lntelfiSn- %lefor CMldren (WISC).nd lhemod,f,ed Gotien.ugh.Harrns Human F,o.re Drawtng (H FOltSef.r and

Percent dlstr#b.tno..f chi!dm.6.11 vearsof a9e. bvP!ace of blrthof mother..5e, a.dsex: Lf.tted S1ates,1963-1965

Wlsc HFD Perc,”t of

Percent of chaldre”

Combined Vwab”lmy 81.ck Dewm

chnldren vwth

Age and w

Cmnbm.!d Mm f!gure woman f,gure nmtherbom ,.

U.s.i Foreign t us.! Foreign S us., Foreign 1 U.S. I FOreIgnq us.,

F.metg”

FO,e,gnl U.a.l Foreign: U.S., F.,.ign, us.

country

Mean de.mtm. IQ

Total, 6.11 “Car, . . . . . . . . 99.6 91,9 1m,3 67.1 100.2 98.2 99.6 100.1 IL> 101.6 103.6 100.3 100.0 100.0 96.6 3.4

Gvcw$ . . . . . . . . . . . . . . . . 99.6 67,0 103.5 80.0 100.1 95.3 39.6 94.9 101.3 95.9 100.s 97.6

?Vcim . . . . . . . . . . . . . .

17.3 26.3 ...

99.4 6S,4 103,3 S2.7 100.2 96.2 99.6 9s.1 10CI.5 101.3 100.9 97.3

8vccws . . . . . . . . . . . . . . .

17.2

99.9 94,1 103,6 66.6 100.2

16.1 .-.

103.0 99.4 160.7 100.4 100.4 100.4 104.1

Llymrs . . . . . . . . . . . . . . . . . .

16.7

99.4

14,8 ... ..-

92,0 100,2 88,0 100.0 97,7 99,6 102.6 1CF3.3 106.1 100.6 100,0 16.7

Iovcars . . . . . . . . . . . . . . . . . .

17,2 -.. ..-

99.6 96,6 100.0 95.4 100,0 102.4 99,6 102.6 180.2 105.1 100.2 100.9 16.2

llwJr5 . . . . . . . . . . . . . . . . . .

17,9

99.6 98.9 103.3 106.0 100.4 93.6 100.1 102.6 103.5 101.7 100.7 102.6 15.9 5.7

B0vs,6.11 Years . 101.1 93.4 102.0 90.7 101.3 97.6 100.2 101.2 1CU2.4 102.0 93.2 90.4 50.9 39.5 . . -..

GMs,6.llymrs 98.2 90.9 98.5 64.7 99,0 96.5 99.0 96.S 101.4 100.3 102.1 102.7 49.1 60,5 . . .

Standard error of mm”

Totd,6.11 ”ems. ,, ..,., 0.55 2.06 0.74 2.06 0.47 2.23 0.55 1.99 0.63 1.93 0.50 2.56 . . -.. . .

Ovmrs 0.85 5,59 0.71 11.26 0.72 0,90 0.60 4.60 0.74 4.07 0.64 5,44 ... ..-

7Ye.3m . . . 0.64 6.43 0.79 6.36 0.64 4.59 0.72 2.34 0.93 3.98 0.67

8vrws . . . . . . . . . . . . . . .

230 . . . ..- .-.

0.51 7.82 0.76 6.47 0.43 13,12 0,63 2.99 0,91 2.41 0.72

Eivcws . 0.67

6.0S ..- .-. . . .

3,82 0,87 697 0.61 5.01 0,81 2.31 0.84 2,34 0.72 3.82 . . . . . . . .

Iowan. . . . . . . . . . . . . . . . . . 0,77 5,22 1,04 3.88 0.71 7.85 0.70 3.86 0,87 4.81 0.77 5.93 . .

ll”e3rs . . . . . . . . . . . . . . . . . . 0.81 5n.16 0.73 53.92 0,87 47s4 0.94 2.91 1.65 4.08 1.0s 4.45 . . . -..

60”s,6.11”,3,s . . . . . . . 0.63 2.7S 0.S3 3,33 0,53 3,43 0,63 1.23 0,63 1.11 0.82 3.65 . . . . . . . .

Glrlv6.llveara ... . . . . 0.53 3.25 0.69 4.15 0.50 2.49 0.58 3.26 0.93 6.S0 0.51 2.79 . . . . .

‘8k1hDla= of mother 12dmm. t).

Table4. Mean deviation lQandstindard error of themean ontheshoR form of the Wechsler intelligence Smlefor Children (WlSC)

andthemodifiad Goodenough-Harris Human Figure Drawing (HFD) tests forand percent distribution of children 6-11 years of age,

by age of mother and of father atthe time of thechild’s birth: United States, 1963-1965

Age of parent at birth

of child

Mother

10-19 years . . . . . . . . . . .

20-24 years....,...,..

25.29 years . . . . . . . . . . .

30-34 years..,..,..,..

35-39 years ., .,,......

40-44 year3 . . . . . . . . . . .

45-54 years . . . . . . . . . . .

Ea$k

15-19 years . . . . . . . . . . .

20.24 years . . . . . . . . . . .

25-29 years . . . . .. m....

30.34 years . . . . . . . . . . .

35-39 years . . . . . . . . . . .

40-44 years . . . . . . . . . . .

45-49 years . . . . . . . . . . .

60years And over . . . . . . .

Mean deviation IQ

94.9

99.0

101.0

100,7

101.1

97.8

90.3

96.2

98.4

100.8

101.0

99.8

100.0

95,5

92.3

95.0

99.4

101.6

101.9

102.4

97.9

88.7

97.6

98.8

101.3

101.8

101.1

100.7

95.6

93.4

96.1

99.9

101.6

100.7

101.0

99.0

93.2

96.0

99.4

101.5

101.4

99.7

100.6

96.7

94.2

97.9

99.5

100.2

100.4

100.6

97.6

91.4

99.2

99.4

100.4

100.2

100.6

99.0

96.8

94.8

98.3

100.8

100.7

101.3

101.7

98.5

96.3

100.3

100.7

101.1

101.3

101.0

100.1

97.1

96.3

99.1

99.7

101.6

101.7

101.4

98.5

86.2

99.6

99.7

101.4

101.2

102.2

100.1

98.4

95.0

Wlsc HFD

Combined Combined

Standard error of mean

0.50

0.65

0.60

0.73

0.92

1.64

4.20

0.79

0.54

0.63

0.74

0.74

0.96

1.33

1.90

0.50

0.55

0.64

0.58

0.96

1.24

4.30

0.86

0.56

0.43

0.65

0.77

1.08

1.51

3.00

Percent

of

:hildren

11.0

30.8

27.3

19.0

9.2

2.5

0.2

2.5

20.6

28.3

23.1

14.0

6.7

2.4

1.4

27
Table 5. Mean deviation IQ and standard error of the mean on the short form of the Wechsler Intelli!fmce Scale for Children (WISC) and the modified Gocdenough. Harris Human

Figure Drawing (HFDI tests for and number and percent distribution of children 6-11 years of as, by numlxr of children under 20 years in the household and sex of child: Unltnd

States, 1963-1965

III Both Boys Girls

sexes IIBoth BOYS Girls

sexes

Wlsc wlSCCo”bineti I HFDCombined

Number of children

under 20 years

in household Soys TGirls soys Girls

Mean deviation IQ Number in thousands Percent

99.6 100.6 99.s

100.5 102.3 100.4

101.5 101.9 103.1

99.7 100.s 100.5

59.3 100.0 100.6

98.0 99.5 9B.1

96.4 9B.B 98.1

93.6 93.7 96.2

Standard error of mean

0.78 0.8B 1.32

0.50 0.75 0.3B

0.50 0.61 0.73

0.56 0.65 0.71

1.00 1.23 0.98

0.91 1.5B 0,91

1,21 1.46 1.73

1.08 1.52 1.32

5.3

1B.6

24.2

20.2

12.6

7.7

5.0

6.4

. . .

. . .

. . .

. . .

.-.

. . .

. . .

. . .

6.6

18.7

24.7

20.s

12,2

7.6

4.7

5.9

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

—

103.9

104.9

102.s

100.7

9B.6

96.6

93.4

902

0.94

0.72

0.58

0.72

1.30

0.92

1.80

1.36

99.1

101.0

101.3

98.7

95.6

92.8

92.0

90.B

101.0

101.9

101.3

100.1

99.s

99.9

B6.9

93.1

9s.0

99.0

101.s

99.4

9B.8

96.0

95.9

84.2

1.24

0.5s

0.76

0.72

0.91

1.02

1.73

1.36

1,261

4,425

5,766

4,804

2,997

1,831

1,189

1,522

684

!,259

!,984

!,513

,474

908

568

713

597

2,166

2,772

2,291

1,523

926

621

S09

6.1

18,6

23.9

19.6

13,0

7.9

5.2

6.8

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

—

1 child . . . . . . . . .

Zchi[dren . . . . . . . . .

3 children . . . . . . . . .

4 children . . . . . . . . .

5 children . . . . . . . . .

6 children . . . . . . . . .

7 children . . . . . . . . .

B children or more . . .

101.6

103.0

102.1

99.B

97.0

94.7

92.7

90.5

104.1

105.4

103.4

100.2

96.2

93.7

91.4

88.4

100.4

101 .s

102.1

100.5

99.1

96.9

95.2

93.7

0.92

0.62

0.49

0.56

0.97

1.05

1.44

1,25

1.06

0.61

0.58

0.66

0.61

1.34

1.30

1.32

1.11

0.74

0.62

0.73

1.41

1.36

1.53

1.45

lchild . . . . . . . . . . .

2 children . . . . . . . . .

3 children . . . . . . . . .

4 children . . . . . . . . .

5 children . . . . . . . . .

6 children . . . . . . . . .

7 children . . . . . . . . .

8 children or more . . .

0.82

0.%

0.43

0.59

0.92

0.96

1.27

1.12

0.94

0.74

0.55

0.75

0.96

1.08

1.39

1.24

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

Table 6. Mean deviation IQ and standard error of the mean on the WISC Vocabulary and Block Design and the modified HFD tests for and percent of children S-11 years of age, by

educational attainment of first parent and number of children under 20 years in the household: United States, 1963-1965

II5-8 9-12 13 years

years years or moro

Education of first parent

I 1 I

Lessthan 5 years I 5-8 years I 9-12 years I

13 years or m m

HFD

103.6

104.1

105.3

105.0

105,1

102.6

105.3

97.5

Number of children

under 20 years

in household

Lessthan

5 years

4.7

7.4

9.4

15.7

19,2

12.2

11.7

19.7

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

F

Wlsc

HFD Vocab. Block

uIafy DesignE

Wlsc

HFD

Vocab- Block

ulary Design

Wlsc WLSC

HFD Vocabulary

Block

Design

VocabularyBlock

Design

Mean deviation IQ

99.4 106.0 100.7

96.7 104.s 101.1

99.9 102.B 101.s

96.2 100.7 100.6

96,2 97.6 100.8

96.8 94.9 98.4

35.3 95.2 98.2

34.5 92.6 96.7

100.0

95.B

97.4

94.4

91.8

90.8

87.7

87.o

99.3

96.2

96.6

95.6

95.0

93.4

93.3

92.6

99.B 110.2

100.3 113.3

100.7 110.5

100.0 108.8

100.9 105.6

98.7 104.4

97.9 105.8

97.9 101.7

106.2

107.3

107.5

108.2

105.7

106,3

104.0

102.9

6.4

14.7

19.2

18.7

13.7

10,2

8.o

9.1

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

1 child . . . . . . . . . . .

2 children . . . . . . . . .

3 children . . . . . . . . .

4 children . . . . . . . . .

5 children . . . . . . . . .

6 children . . . . . . . . .

7 children . . . . . . . . .

B children or more . . .

94.0

S9.5

B5.4

88.3

83.0

83.0

S1 .6

79.1

6.60

3.84

2.lB

1.46

2.24

2.60

3.W

2.60

90.2

92.3

91.2

90.7

89.5

89.5

S7.7

87.4

1.77

2,63

1.36

O.B1

1.41

1.Oa

1.43

1.20

S9.5

92.8

93.5

90.3

93,0

30.1

35.9

Standard error of mean

1 child . . . . . . . . . . .

2 children . . . . . . . . .

3 children . . . . . . . . .

4 children . . . . . . . . .

5 children . . . . . . . . .

6 children . . . . . . . . .

7 children . . . . . . . . .

S children or more . . .

1.66

1.00

1.20

1.17

1.41

1.74

1.27

1.50

0.96

0.54

0.71

0.51

0.84

1.11

1.s3

1.50

1.01

0.65

0.75

0.74

0.92

1.35

1.55

1.40

2.59

0.B5

0.70

1.11

1.14

2.85

2.71

2.BO

2.S5

1.15

0.71

1.28

2,78

2.94

4.57

3.70

1.97

0.65

0.92

0.84

1.77

2.16

5.62

3.80 L

..

.

..

.....

.

.

..

.

.

.

..

.

.

.

.

.

..

.

.

.

.

.

..

.

....

4.19

2.44

2.15

1.44

2.19

1.55

2.54

2.00L

0.97 1.29

1.17 0.71

0.96 1.OB

1.10 1.oB

1.36 1.34

1.29 1.23

1.69 1.44

1.50 1.30

0.80

0.55

0.61

0.68

0.77

1.29

1.75

1.50

28
Tabla 7. Mean deviation IQ and standard error of the mean on the short form of the Wechsler Intelligence Scale for Children (w[SC)

and the modified Goodenouqh-Harris Human Figure Drawing (H FD) tests for and percent distribution of children 6-11 years of

age, by number of deceasad si~lings (born dead or-who died later): United States, 1963-1965

Number of decaased

siblings

Wlsc

HFD

99.7

98.6

98.1

99.0

88.4

92.6

99.9

96.6

93.9

83.3

90.9

98.2

Wlsc

HFD

‘ercent

of

Combined Vocabulary :hildren Block

Design

Born dead

None, ,, . . . . . . . . . . . . .

I sibling . . . . . . . . . . . . . .

2siblings . . . . . . . . . . . . .

3siblings . . . . . . . . . . . . .

4siblings . . . . . . . . . . . . .

5siblingsormore .,, . . . .

Liveborn but died

before surtq

None . . . . . . . . . . . . . . . .

I sibling . . . . . . . . . . . . . .

2siblings . . . . . . . . . . . . .

3siblings . . . . . . . . . . . . .

4siblings . . . . . . . . . . . . .

5siblingsormore . . . . . . .

Mean deviationlQ Standard error of mean

99.6

97.3

99.4

97.8

86.2

96.6

88.9

95.2

91,7

84.8

92.1

87.6

100.2

98.0

98.2

97,5

86.6

95.6

100.5

95.5

91,8

81.8

94.5

87.6

100.1

97.7

101.9

98.9

87.4

98.3

100.4

96.0

92.7

88.0

90.8

8S.6

0.60

0.74

2.99

●

*

*

0.58

0.82

1.82

3.49

●

*

0.80

0.96

2.50

*

*

*

0.77

1.19

3.00

5.75

*

*

0.50

0.77

3.68

*

*

●

0.50

0.74

0.88

2.28

●

*

0.60

0.72

2.90

*

●

*

0.51

1.04

1.79

6.21

●

●

93.9

4.4

1.1

0.3

0.2

0.1

92.6

5.8

1.1

0.3

0.1

0.1

Table8. Mean deviation IQ and standard srror of the mean on the short form of the Wechsler Intelligence Scale for Children (WISC) and the modified

Gcmdenough-Harris Human Figure Drawing (HFD) tests for and number andpercent distributicm of children 6-11 years, by age order of the child in the

family: United States, 1963-1965

Wlsc I HFD WISCCombined I HFDCOmbined

Number Of

children

in thousands

6,S97

6,969

5,114

2,664

1,142

999

. . .

. . .

. . .

-..

. . .

.-.

Percent

of

Age order of

child in family Vocab- Block Man Woman :ombi ned Combined

ulary Design Scale Scale

Boys Girls Boys Girls

Mean deviaticm IQ

First, . . . . . . . . . .

Sasond . . . . . . . . .

Third . . . . . . . . . . .

Fourth . . . . . . . . . .

Fifth . . . . . . . . . . .

Sixth orlater . . . . .

101.2 102.9

100.5 101.5

99.4 99,3

96.5 96.1

93.8 92.3

92.1 91.3

100.8

100.8

100.7

98.1

88.5

94.1

0.53

0.45

0.62

0.92

1.18

1.00

100.3

100.2

99.8

97.9

96.7

96.2

101.4

101.3

100.6

9B.9

96.8

96.0

100.8

100.8

100.9

99.3

98.6

99.4

99.3

89.1

98.5

95.7

93.7

92.1

101.2

100.8

100.2

9S.2

96.1

96.4

99.3

99.5

99.5

97.6

97.2

96.0

29.0

29.3

21.5

11.2

4.8

4.2

. . .

. . .

. . .

. . .

.-.

---

103.0

101.9

100.3

97.3

93.8

92.1

0.71

0.61

0.87

1.22

1.71

1.20

Standarderrorof mean

1

0.46 0.65 0.57

0.56 0.72 0.47

0.58 0.73 0.71

0.98 1.36 0.70

1.23 1.84 1.30

1.50 1.60 1.80

First, . ...,.,...

Second . . . . . . . . .

Third, . . . . . . . . . .

Fourth, . . . . . . . . .

Fifth . . . . . . . . . . .

Sixth or later . . . . . J0.60 0.78

0.52 0.71

0.62 0.77

0.87 1.07

1.28 1.46

1.10 1.50 _l---.L 0.64 0.62 0.61

0.57 0.73 0.56

0.60 0.81 0.74

0.81 1.35 0.86

1.19 1.90 1.48

1.20 1.70 1.60

29
Table9. Mean deviation lQ and standard error of themean onthe WISCVaabulaW and Block Design tests forchildren6-ll years ofage, by age

order ofchild in family andnumber ofchildren under 20years in the household: United States, 1963-1966

WISC Vocabulary WISC Block Design

Age order of child Number of persons under 20 years in household Number of persons under 20 years in household

in family

=

100.6 92.5

97.6 94.5

100.2 97.9

98.4 95.6

98.8 95.7

- 94.1

2.07 1.61

0.97 1.40

1.23 1.66

1.23 0.96

2.48 1.19

. . . 1.01

IEEE ZEc 1 12 3 4 2

Mean deviation IQ

98.1

95.5

95.8

96.3

95.6

89.4

90.1

92.5

91.5

91.2

91.3

104.1 106.0 100.4

104.9

103.9

103.3

103.1

99.1

100.4

100.3

100.9

0.96

0.96

0.93

0.99

102.0

101.7

101.6

102.3

102.2

0.98

0.57

0.68

---

. . .

.-.

99.8

101.0

100.6

100.6

1.06

0.86

0.84

1.15

. . .

. . .

First.............

Second . . . . . . . . . . . .

Third . . . . . . . . . . . . .

Fourth . . . . . . . . . . . .

Fifth . . . . . . . . . . . . .

Sixth orlater . . . . . . . .

Standard error of mean

w

First . . . . . . . . . . . . .

Second . . . . . . . . . . . .

Third . . . . . . . . . . . . .

Fourth . . . . . . . . . . . .

Fifth . . . . . . . . . . . . .

Sixth orlater . . . . . . . .

0.94 0.97

0.73

0.70

0.75

0.80

Table 10. Mean deviation lQandstandard error of themean byageorder ofchild in family andeducation ofsecond parent onthemodified HFD

test and by age order of child in family and education of first parent on the WISC Vocabulary and 810ck Design tests: United Stetes,

1963-1965

WISC Vocabulary WISC Block Design

Education of first parent Education of first parant

HFD

Age order of Education of second parent

child in family

13 years

or more

103.5

103.2

104.1

105.5

106.9

95.6

Under

5 years

88.2

84.4

84.0

81.6

81.9

81.7

Mean deviation IQ

95.5 102.8

94.0 101.6

84.1 100.3

90.6 99.1

91.7 96.1

92.2 94.2

96.6 100.6 106.6

94.7 101.2 107.1

96.9 100.6 108.6

93.2 100.4 106.3

95.5 99.0 107.6

92.6 97.6 98.0

First . . . . . . . . . . .

Second . . . . . . . . .

Third . . . . . . . . . .

Fourth . . . . . . . . .

Fifth . . . . . . . . . .

Sixthorlater . . . . .

95.2

89.1

89.0

88.1

86.6

90.9

95.6

97.8

95.5

95.0

95.5

99.5

111.5 91.0

110.7 90.0

107.8 89.7

106.8 88.1

103.2 88.7

99.8 88.9

100.8

100.6

101.0

99.0

99.6

98.3

0.43

0.67

0.59

1.11

0.96

2.90

Standard error of mean

First . . . . . . . . . . .

Second . . . . . . . . .

Third . . . . . . . . . .

Fourth . . . . . . . . .

Fifth . . . . . . . . . .

Sixth or later . . . . .L

1.62 0.94

1.93 1.20

2.12 0.92

3.48 1.16

3.53 2.08

5.54 3.18

0.96

0.53

1.11

1.53

3.85

5.95 I

1.64 0.99 0.66

2.31 0.97 0.49

2.15 1.09 0.60

2.82 0.85 0.70

1.59 1.63 1.08

2.07 1.35 1.90

0.78

0.67

0.70

0.82

1.85

22.84

1.11

0.90

1.41

0.89

1.25

2.42

0.84

1.00

1.04

1.06

1.65

1.42

0.45

0.43

0.48

0.87

1.10

1.61

1.10

0.86

1.06

1.67

3.32

22.08

30
Table Il. Mean deviation lQands@ndard error oftiemean ontheshoti form of the Wechsler intelligence Smlefor Children (WlSC)

and the modified Goodenough-Harris Human Figure “Drawing(HFD) tests forchildren 6-11 years of age, bypresence orabsenceof

medical complications of motharduring pregnancy and byedumtion of thesecond parent onthe WlSC: United Statas,1963-1965

Item

Combinad . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .’ . . . . . . . . . . . . . .

Vocabulary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Block Design . . .,, .,.,. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Combinad . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Man Scale . . . . . . . . . ...’... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Woman Scale . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

WISC Combined

Education of second parant:

Lessthan 5yaars . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

5-8years ..,........,.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

9.12years . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

13yaars ormore . . . .. o..... . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Medical complications of mother during pragnancy

Some None

Mean deviation IQ

100.1

101.6

100.0

99.6

100.8

100.6

92.1

92.4

100.6

108.0

99.9

100.6

100.4

99.6

100.5

100.5

85.2

92.5

101.0

108.3

Some I None

Standard error of mean

0.86

1.08

0.99

0.64

1.08

0.70

3.72

1.44

0.71

1.38

0.65

0.86

0.63

0.48

0.59

0.42

1.40

0.72

0.31

0.82

31
Table 12. Mean deviation lQandstandard error of the mean ontheshort form of the Wechsler intelligence Smlefor Children (WISC)and themodified

Goodenough-Harris Human Figure Drawing (HFD) tests for and number and parcent distribution of children 6-11 years of age, by birthweight, Iangth of

baby ’s stay in hospital after bir’th, congenital malformations and birth injuries shown on birth certificate, handedness, and twin status: Unitad Statas,

1963-1965

Item

Birthwaight

Undar5 pounds . . . . . . . .

5-10 pounds . . . . . . . . . .

More than 10 pounds . . . .

Langth of baby’s stay

in hospital after birth

Undarl week . . . . . . . . .

l-2waaks . . . . . . . . . . . .

0var2waeks . . . . . . . . . .

Congenital malformation

Condition recorded on birth

certificetq . . . . . . . . . .

None recorded . . . . . . . . .

Birth injury

Condition recorded on

birth certificate . . . . . .

Nona recorded . . . . . . . . .

Handedness

Right . . . . . . . . . . . . . . .

Left . . . . . . . . . . . . . . . .

Ambidextrous . . . . . . . . .

Twin status

Notatwin . . . . . . . . . . .

Identiceltwin . . . . . . . . .

Fratarnaltwin . . . . . . . . .

Twin, type unknown . . . .

94.6

99.6

95.6

100.4

101.7

95.8

97.6

100.1

93.1

99.6

99.0

99.1

90.6

99.4

98.4

96,0

86.1

HFD

==ll=E=

95.5

100.2

95.3

101.2

102.9

96.7

97.6

100.8

91.4

100.4

99.6

100.3

88.6

100.0

9B.O

96.4

85.6

Mean deviation IQ

95.0

10Q.2

97.1

100,9

101.9

96.2

98.6

100.6

95.8

100.1

99.7

88.2

92.4

100.0

100.2

96,8

87.8

96.0

89.7

98.0

100.3

100.5

96.0

100.0

99.7

99.4

88.1

88.6

88.2

92.5

88.6

96.8

97.4

86.6

96.3

100.5

97.4

101.2

100.6

98.0

100.9

107.0

99.9

100.4

99.9

97.1

100.6

92.6

95.7

84.1

97.5

100.9

97.7

101.3

102.0

98.0

99.6

100.9

96.1

100.3

100.4

100.0

75.0

100.5

100.9

100.7

91.2

I

Wlsc HFD

Combined Combined

Standard error of maan

0.66

0.63

1.61

0.44

0.99

0.72

2.08

0.52

5.90

0.68

0.67

0.62

21.96

0.61

2.36

1.65

4.06

1.28

0.68

1.43

0.41

0.98

1.27

3.06

0.88

3.96

0.80

0.53

0.55

22.97

0.60

2.33

2.76

2.58

Numberof

children

in thousands

690

22,785

308

21,210

1,780

7~4

238

23,646

71

23,713

21,215

2,545

24

23,332

143

285

24

‘arcent

of

;hiidran

2.9

95.8

1.3

88.8

7.4

3,0

1.0

99.0

0.3

99.7

89,2

10,7

0.1

98.1

0.6

1.2

0.1

32
Table 13. Mean deviation lQ and standard error of the mean ontheshort formof the Wechsler Intelligence Scale for Children (WISC) and themcdified GoodenouirhHarris Human I%ure Drawinq (HFD)tesS forandwrcent distribution ofchildwn6-ll Years of a9e. bv critical asPects of early developmental history: United States,

1963-1965 -

Early developmental

history

Acceptance of change

from breast feeding

No problem ., ..,,,.

Someproblem . . . . . . .

Considerable problem . .

Age child first walked

Under 12 months ., . . .

12-18 months . . . , . . .

0ver18 months . . . . . . .

Don’t know . . . . . . . . .

Age child first spoke

Under 12 months . . . . .

12-18 months . . . . . . .

0vw18 months . . . . . . .

Don$t know . . . . . . . .

Problems with talking

Some . . . . . . . . . . . . . .

None . . . . . . . . . . . . . .

Don’t know .,.,.....

Learning speed

Faster . . . . . . . . . . . . .

Average . . . . . . . . . . . .

Slower . . . . . . . . . . . . .

Don’t know . . . . . . . . .

Health at 1 year

Good, . . . . . . . . . . . . .

Fair . . . . . . . . . . . . . . .

Poor . . . . . . . . . . . . . .

80YS and girls

Combined

F

Mean deviation IQ

100.2

96.6

96.2

1Oo.c

99,6

89.9

94.6

101.0

99.2

94.4

96.9

85.0

99.8

●

102.8

99.0

89.2

95.4

99.7

97.0

92.7

100.6

98.5

98.9

100.3

88.6

80.6

94.0

101.1

99.2

94.6

98.1

96.0

99.9

.

102.1

99.4

90.6

98.4

88.9

97.8

92.7

Combined

T

Standard error

0.83

1.47

2.33

0.66

0.56

1.19

1.67

0.59

0.59

1.19

0.67

0.86

0.60

.

0.88

0.61

1.23

1.83

0.63

0.74

1.06

0.76

1.62

3.10

0.61

0.47

1.37

1.48

0.64

0.57

1.20

0.80

0.86

0.49

.

0.75

0.46

1.49

2.08

0.51

0.76

2.15

Mean deviation IQ

101.8

97,0

100.7

fol.5

100.9

90.3

93.5

102.6

100.7

96.3

98.2

96.6

101.1

.

105.6

100.4

90.2

93.8

101.0

98.9

95.2

101.5

98.0

101.6

101.4

98.9

90.8

93.3

101.9

100.0

95.7

97.9

86.5

10Q.6

.

103.9

99.9

92.2

98.4

100.4

89.0

93.1

98.6

96.4

96.1

98.5

98.2

89.4

85.5

99.5

97.4

81.6

97.6

92.7

98.4

.

100.8

97.5

87.2

97.4

98.4

94.6

80.1

89.7

98.9

86.6

99.2

99.4

80.4

94.6

100.4

98.4

93.0

88.3

95.2

89.2

.

100.8

98.8

87.4

98.5

88.3

96.3

92.2

100.6

98.1

101.0

100.8

100.2

88.4

94.8

102.0

99.6

94.1

97.0

93.8

100.5

●

104.4

89.5

87.0

94.8

100.4

97.1

92.3

101.1

96.4

96.6

100.4

100.3

92.4

95.5

101.1

100.0

95.9

98.0

97.5

100.2

.

102.8

99.7

92.4

97.0

100.3

88.1

94.1

101.9

97.8

99.2

101.8

100.2

90.8

84.1

102.1

100.3

85.8

99.0

96.3

100.9

.

103.8

100.3

92.1

97.5

1CO.8

8S.5

94.8

101.2

103.4

1Cm.3

100.8

101.0

92.3

96.2

102.1

89.9

84.8

99.0

97.0

1CCI.8

.

103.0

10+3.2

89.1

103.2

1M.9

97.8

92.7

-

‘ercent

of

90.5

7.9

1s

47.7

47.3

3.6

1.4

42.8

41.1

8.5

7.6

8.4

91.6

.

20.2

74.9

4.2

0.7

90.8

7.6

1.7

33
Table 14. Mean deviation IQ and standarderror of the mean cm the short form of the Wechsler Intelligence Scale for Children (WISCI and the modified Goodenough.

Harris Human Figure Drawing (HFD) tests for and percent of children 6-11 years of age, by findines of congenital and acquired chronic conditions on survey examlna.

tion: United States, 1963-1965

Boys Girls

Combined Combined Boys and girls

~

%rcent

of

hildren

0.3

0.1

1.9

0.7

97.4

96.4

1.9

1.7

0.5

0.3

0.6

2.2

Boys and girls

Combined

=1=

Combined

T

Item

Wlsc HFD Wlsc HFD

Vocab. Block Man Woman

ulary Design scale scale

Medical history of Mean deviation IQ Standard error Mean deviation IQ

2.79

3.20

2.23

2.60

0.62

0.62

1.32

2.!M

2.31

4.35

2.99

1.61

3.93

6.63

1.64

1.59

0.52

0.52

1.70

2.27

. . .

.-.

. . .

. . .

91.8

80.0

92.4

89.7

98.4

98.4

91.4

98.1

81.8

73.6

94.2

98.4

86.7

72.2

95.5

95.8

99.2

99.2

86.3

95.3

. . .

-..

. . .

.-.

93.4

83.2

93.6

96.9

100.4

100.4

93.5

98.5

90.1

67.2

96.9

100.5

94.7 I

83.6

94.7

96.7

99.7

99.7

94.1

96.1

69.9

76.8

96.9

99.2

91.9

78.7

95.1

97.1

99.9

99.9

91.6

94.8

.-.

. . .

. . .

-..

Epilepsy . . . . . . . . . . . .

Cerebral palsy . . . . . . . .

98.8

87.2

96.5

102.2

101.1

101.1

96.4

94.6

92.0

79.2

100.6

99.7

96.4

65.2

94.8

98.1

100.6

100.6

94.5

94.4

.-.

. . .

. . .

. . .

97.2

84.6

97.0

97.8

100.3

100.3

95.9

96.8

80.9

87.3

98.4

99.1

93.8

61.8

95.5

98.5

100.9

100.8

96.0

94.3

. . .

. . .

. . .

-..

92,1

77.2

96.5

96,6

100.9

100.9

88.4

97.4

. . .

. . .

. . .

. . .

Present health findings

on examination

Heart condition:

Congenital . . . . . . . .

Acquired . . . . . . . . .

None . . . . . . . . . . . .

Neurological.musc uloskeletal condition:

None . . . . . . . . .

Congenital . . . . . .

Acquired . . . . . . .

Cerebral palsy, other

cerebral problems or

minimal cerebral

dysfunction . . . . . . .

Mongolism or mental

retardation . . . . . . . .

Eye disorderc . . . . . . . .

Musculoskeletal joint

disorders only . . . . . .

Table 15. Mean deviation lQandstandard error of themean onthe WISCVocabularv and Block Desiqnand themdified HFDtests forchildren6-ll

years ofage, byrace, kindergarten ornursery school experience, andeducational attainment of;irat parenti United Statas,1963-1965

Child attended kindergarten or nursery school Child did not attend kindergarten or nursery school

WISC Vocabulary WISC Block Design HFD WISC Vocabulary WISC Block Design HFD

Education of first

parent I t 1 I ,

White Negro White Negro White Negro Whita Negro White Negro White Negro

Mean deviation IQ

All children . . . . . . 104.3 I 90.1 103.4 I 91.6 101.7 96.9 I

96.3 I65.0 I

97.4 88.1

~

97.5 91.0

I

Lessthan 6years . . . . . . .

5-8years . . . . . . . . . . . .

9-12yaars . . . . . . . . . . . .

13yeara0rm0re . . . . . . .

87.3 84.1

99.0 87.2

103.0 91.6

110.6 99.1

92.3 88.6

99.1 90.4

102.4 92.3

108.2 95.6

91.5

96.3

99.0

102.2

85.4

92.2

93.3

97.8

Standard error of mean

0.70 1.08 0.54 0.27 0.54 0.74 1.53 2.28 0.77 0.96 0.88 1.20

2.69 2.s4 1.67 1.32 2.78 1.45 2.26 1.65 0.57

0.83

0.87 1.04 1.64

1.05 0.s4 0.38 1.08 1.68 0.87 3.02 1.02 0.94 1.05 1.59

0.55 1.17 0.44 0.54 0.50 0.71 0.90 2.26 0.48 0.89 0.79 1,77

0.70 2.08 0.78 2.38 0.57 2.46 1.03 7.66 1.02 2.66 1.10 4.98

All children . . . . . .

Less than 6 years . . . . . . .

5-S years . . . . . . . . . . . .

9-12 years . . . . . . . . . . . .

13years ormore . . . . . . .

_ -—-——

34
.

APPENDIX I

STATISTICAL NOTES

The Survey Design

The sample design for the second cycle of the

Health Examination Survey, similar to the one

used for the first cycle, was that of a multistage,

stratified probability sample of loose clusters of

persons in land-based segments. Successive elements dealt with in the process of sampling are

primary sampling unit (PSU), census enumeration district (ED), segment, household, eligible

child (EC), and finally, the sample child (SC).

At the first stage, the nearly 2,000 PSU’S into

which the United States (including Hawaii and

Alaska) has been divided and then grouped into

357 strata for use in the Current Population

Survey and the Health Interview Survey were

further grouped into 40 superstrata for use in

Cycle II of the Health Examination Survey. The

average size of each Cycle II stratum was 4.5

million persons, and all fell between the limits of

3.5 and 5.5 million. Grouping into 40 strata was

done in a way that maximized homogeneity of

the PSU’S included in each stratum, particularly

with regard to degree of urbanization, geographic proximity, and degree of industrialization. The 40 strata were classified into four

broad geographic regions (each with 10 strata)

of approximately equal population and cross

classified into four broad population density

groups (each having 10 strata). Each of the 16

cells contained either two or three strata. A

single stratum might include only one PSU (or

only part of a PSU as, for example, New York

City, which represented two strata) or several

score PSU’S.

To take account of the possible effect that

the rate of population change between the 1950

and 1960 census might have had on health, the

10 strata within each region were further classified into four classes, ranging from those with

no increase to those with the greatest relative

increase. Each such class contained either two or

three strata.

One PSU was “then selected from each of the

40 strata. A controlled selection technique ww

used in which the probability y of selection of a

particular PSU was proportional to its 1960

population. In the controlled selection an attempt was also made to maximize the spread of

the PSU’S among the States. While not every one

of the 64 cells in the 4 X 4 X 4 grid contributes

a PSU to the sample of 40 PSU’S, the controlled

selection technique ensured the sample’s matching the marginal distributions in all three dimensions and being closely representative of all cross

classifications.

Generally, 20 ED’s were selected within a

particular PSU. The probability of selection of a

particular ED was proportional to its population

in the age group 5-9 years in the 1960 census,

which by 1963 roughly approximated the population in the target age group for Cycle II. A

similar method was used for selecting one

segment (cluster of households) in each ED.

Each of the resultant 20 segments was either a

bounded area or a cluster of households (or

addresses). All children in the age range 6-11

years normally resident at each household or

address were considered EC’S. Operational considerations made it necessary to reduce the

number of prospective examinees at any one

location to a maximum of 200. The EC’s to be

excluded for this reason from the SC group were

determined by systematic subsampling.

The total sample thus selected for the examination included 7,417 children (SC’s) from 25

different States in the age group 6-11 years, with

approximately 1,000 at each of the single years

of age.

35
Reliability

Measurement and assessment processes employed in the survey were highly standardized

and closely controlled. Of course this does not

mean that the correspondence between the real

world and the survey results is exact. Data from

the survey are imperfect for three major reasons:

(1) results are subject to sampling error, (2) the

actual conduct of a survey never agrees perfectly

with the design, and (3) the measurement or

assessment processes themselves are inexact even

though standardized and controlled.

The first report on Cycle 114 describes in

detail the faithfulness with which the sampling

design was carried out. It notes that 7,119 out

of the 7,417 sample children were examined.

This is a response rate of 96 percent. The

examined children were a highly representative

sample of children of this age in the noninstitutional population of the United States. The

response levels for the various demographic

subgroups-including those for age, sex, race,

region, population density, parent’s educational

level, and family income–show no marked

differentials. Hence it appears unlikely that

nonresponse could have biased the findings

markedly in these respects. Further description

of the sample design and estimation procedures

is contained in a subsequent report.73

The general measures used to control the

quality of data from this survey have been cited

previously.4 as have those relating specifically to

the psychological test measures.6 $9

Data recorded for each sample child are

inflated in the estimation process to characterize

the larger universe of which the sample child is

representative. The weights used in this inflation

process are a product of the reciprocal of the

probability of selecting the child, an adjustment

for nonresponse cases, and a poststratified ratio

adjustment that increases precision by bringing

survey results into closer alinement with known

U.S. population figures by color and sex for

single years of age 6 through 11.

In the second cycle of the Health Examination Survey, the sample was the result of three

stages of selection—the single PSU from each

stratum, the 20 segments from each sample PSU,

and the SC’s from the EC’S. The probability of

selecting an individual child is the product of the

probability of selection at each stage.

Since the strata are roughly equal in population size and a nearly equal number of sample

children were examined in each sample PSU, the

sample design is essentially self-weighting with

respect to the target population; that is, each

child 6 through ,11 years had about the same

probability of being drawn into the sample.

The adjustment upward for nonresponse is

intended to minimize the impact of nonresponse

on final estimates by imputing to nonrespon’dents the characteristics of “similar” respondents.

Here similar respondents were judged to be

examined children in a sample PSU having the

same age in years and sex as children not

examined in that sample PSU.

The poststratified ratio adjustment used in

the second cycle achieved most of the gains in

precision that would have been attained if the

sample had been drawn from a population

stratified by age, color, and sex and made the

final sample estimates of population agree exactly with independent controls prepared by the

Bureau of the Census for the noninstitutional

U.S. population as of August 1, 1964 (approximate midsurvey point), by color and sex for

each single year of age 6 through 11. The weight

of every responding sample child in each of the

24 age, color, and sex classes is adjusted upward

or downward so that the weighted total within

the class equals the indepe~dent

control.

Sampling and Measurement Error

population

In the present report, reference has been

made to efforts to minimize bias and variability

of measurement techniques.

The probability design of the survey makes

possible the calculation of sampling errors. The

sampling error is used here to determine how

imprecise the survey test results may be because

they come from a sample rather than from the

measurements of all elements in the universe.

The estimation of sampling errors for a study

of the type of the Health Examination Survey is

difficult for at least three reasons: (1) Measurement error and “pure” sampling error are

confounded in the data—it is not easy to find a

procedure which will either completely include

both or treat one or the other separately, (2) the

survey design and estimation procedure are

36
complex and accordingly

tionallv involved techniques

require computa-

.

for the calculation

of variances, and (3) thousands of statistics

come from the survey, many for subclasses of

the population for which there are few cases.

Estimates of sampling error are obtained from

the sample data and are themselves subject to

sampling e~or, which may be large when the

number of cases in a cell is small or occasionally

even when the number of cases is substantial.

Estimates of approximate sampling variability

for selected statistics used in this report are

presented in the detailed tables. These estimates

have been prepared by a replication technique

that yields overall variability through observation of variability among random subsamples of

the total sample. The method reflects both

“pure” sampling variance and a part of the

measurement variance.

In accordance with usual practice, the interval

estimate for any statistic may be considered the

range within one standard error of the tabulated

statistic, with 68-percent confidence, or the

range within two standard errors of the tabulated statistic, with 95-percent confidence. The

latter is used as the level of significance in this ,

report.

An approximation of the standard error of a

difference d =x - y of two statistics x and y is

given by the formula

where S% and SY are the sampling errors,

respectively, of x and y.

Small Categories

In some tables magnitudes are shown for cells

for which the sample size is so small that the

sampling error may be several times as great as

the statistic itself. Obviously in such instances

the statistic has no meaning in itself except to

indicate that the true quantity is small. Such

numbers, if shown, have been included in the

belief that they may help to convey an impression of the overall story of the table.

37
APPENDIX II

DEMOGRAPHIC AND SOCIOECONOMIC TERMS

Age.–The age recorded for each child was the

age at last birthday on the date of examination.

The age criterion for inclusion in the sample

used in this survey was defined in terms of age at

time of interview. Since the examination usually

took place 2 to 4 weeks after the interview,

some of those who w,ere 11 years old at the time

of interview became 12 years old by the time of

examination. There were 7.2 such cases. In the

adjustment and weighting procedures used to

produce national estimates, these 72 were included in the 1l-year-old group.

Race.–The age order of the child is their

relative ranking by date of birth. Race was

recorded as “white,” “Negro,” or “other.$’

“Other” included American Indians, Chinese,

Japanese, and all races other than white or

Negro. Mexican persons were included with

“white” unless definitely known to be American

Indian or of another race. Negroes and persons

of mixed Negro and other parentage were

recorded as “Negro.”

Geographic re&”on,–For purposes of stratification the United States was divided into four

geographic regions of approximately equal population. These regions, which correspond closely

to those used by the U.S. Bureau of the Census,

were as follows:-

Region

Northeast . . .

Midwest . . . .

South . . . . . .

States included

Maine, Vermont, New Hampshire, Massachusetts, Connecticut, Rhode Island, New York,

New Jersey, and Pennsylvania

Ohio, Illinois, Indiana, Michigan, Wisconsin, +Minnesota,

Iowa, and Missouri

Delaware, Maryland, District

of Columbia, West Virginia,

Virginia, Kentucky, TennWest . . . . . . .

essee, North Carolina, South

Carolina, Georgia, Florida,

Alabama, Mississippi, Louisiana, and Arkansas

Was hington, Oregon, California, Nevada, Ne-w Mexico,

Arizona, Texas, Oklahoma,

Kansas, Nebraska, North

Dakota, South Dakota, Idaho,

Utah, Colorado, Montana,

Wyoming, Alaska, and Hawaii

Urban and rural. –The definition of urban and

rural areas was the same as that used in the 1960

census. According to this definition, the urban

population was comprised of all persons living in

(a) places of 2,500 inhabitants or more incorporated as cities, boroughs, villages, and towns

(except towns in New England, New York, and

Wisconsin); (b) the densely settled urban fringe,

whether incorporated or unincorporated, of

urbanized areas; (c) towns in New England and

townships in New Jersey and Pennsylvania that

contained no incorporated municipalities as subdivisions and had either 2,500 inhabitants or

more, or a population of 2,500 to 25,000 and a

density of 1,500 persons or more per square

mile; (d) counties in States other than the New

England States, New Jersey, and Pennsylvania

that had no incorporated municipalities within

their boundaries and had a density of 1,500

persons or more per square mile; and (e)

unincorporated places of 2,500 inhabitants or

more not included in any urban fringe. The

remaining population was classified as rural.

Urban areas are further classified by population size for places within urbanized areasand

other urban places outside urbanized areas.

Family income. –The income recorded was

the total income of the past 12 months received

by the head of the household and all other

38
household members related to the head by

blood, marriage, or adoption. This income was

the gross cash income (excluding pay in kind)

except in the case of a family with their own

farm or business, in which case net income was

recorded.

Parent. –A parent was the natural parent or,

in the case of adoption, the legal parent of the

child. When both parents were present in the

household, the mother is referred to here as the

second parent.

Guardian. –A guardian was the person responsible for the care and supervision of the

child. He (or she) did not have to be the legal

guardian to be considered the guardian for this

survey. A guardianship could od”y exist when

the parent(s) of the child did not reside within

the sample household.

Head of household. –Only one person in each

household was designated as the “head.” He (or

she) was the person who was regarded as the

“head” by the members of the household. In

most cases, the head was the chief breadwinner

of the family, although this was not always true.

In this report the head of household is also

referred to as the first parent.

Education of parent or guardian. –This was

recorded a“ he highest grade completed in

school. - only grades counted were those

attended ;.. ~ regular school where parents were

given formal education in graded public or

private schools, whether day or night school,

and whether attendance was full or part time. A

“regular” school is one which advances a person

toward an elementary or high school diploma, or

a college, university, or professional school

degree. Education in vocational, trade, or business schools outside the regular school system

was not counted in determining the highest

grade of school completed.

39
APPENDIX Ill

HOUSEHOLD QUESTIONNAIRE AND MEDICAL HISTORY ITEMS

– CONFIDENTIAL - The National Health Survey is authorized by Public Law 652 of the 84th Congress (70 Stat.

489; 42 U.S.C. 305). All information which would permit identification of rhe individual will be held strictly

confidential, will be used only by persons engaged in and for the purposes of the survey and will not be disclosed or released to others for any other purposes (22 FR 1687).

FORM t4ti5-tiE5-2

[11-13-63)

U.S. DEPARTMENT OF COMMERCE

BUREAU OF THE CENSUS

ACTING AS COLLECTING AGENT FO@ THE

U.S. PUBLIC HEALTH SERVICE

NATIONAL HEALTH SURVEY

2. (a) Address or description of location (include city, zone, and State)

1 ALL I

I

2 HOW~re~s). . ~elat~ to the head of he hQuseha[d?

(Enter relationahfp to head, for example: wffe, dau~hter, stepeon, gtandaon, mother-in-law, partner, roomer~e wife, etc.)

r _ ASK FOR PARENTS OR GARDIANS OF EC [

7. Where were yau born?

(Check u.S. box or write in name of country)

I

9. What is the highest grade you attended in schaal? i

Q None

(Circle hfgheat grade attended or mark 8CNone. >8} IElern. . . . 12345678

(If attended, ask): High . . ..l 234

(a) Did you finish this grade (year)? College 1 2 3 4 5+

---—- ----- _-q

. n Yes a No

I ,ALL E C HOUSEI+OLDS 1

\ 4. Which of these in came graups represents your tatal combined farni ly incame for the past 12 ‘months, that is,

yaur’s, your -- ‘s, etc? (Show Income Flash Card HES-2(b). ) Include income from all sources, such as wages,

salaries, rents from praperty, Sacial Security, or retirement benefits, help from relatives, etc.

40
CONFIDENTIAL - The National Health Survey is authorized by Public Law 6.52 o/ FORM APPROVZr.

the 84th Congress (70 Stat. 489; 42 U.S. C. 242c). All in/onnation wbicb would

BuDGET 13UREAU NO. 68. R620-s4,6

permit identification o/ the individual wiI1 be held strictly confidential, will be used only by persons engaged in

und for the purposes o/ the survey and will not be disclosed or released to others /or any other purposes (22 FR 1687’).

DEPARTMENT OF HES-25 6

HEALTH, EDUCATION, AND WELFARE

PUBLIC HEALTH SERVICE (1-5)

NATIONAL HEALTH SURVEY

CHILD’S MEDICAL HISTORY - Parent

NAME OF CH!LO (Last, First, MiaHle) SEGMENT SERIAL COL. NO.

(6-1 1)

NoTE: Please complete this form by checking the correct boxes and/or filling in the blanks where applicable.

When you have completed it, keep it until the representative of the Health Examination Survey calls on you

within a few days. If there are some questions you do not understand, please complete the others and the person who

comes for the form wi H help you with the ones that were unclear.

1. SEX I 2. AGE [ 3. DATE OF SIRTH (Monrb. Day, Year)

(12-14)

(15)

(17)

(18)

(21)

(22)

I o Male z o Female

4. PLAcE OF BIRTH (C ity or TOW Stnte) 5. WAS THIs CHILO BORN IN A HOSPITAL?

I m Yes 213N0 3 u Don’t know

IF YES: ( Question 5)

A. About how long did you (the mother) stay in the hospital after the baby was born?

t u 1 week or less 2 u 1 to 2 weeks 3 u Over 2 weeks 4 0 Don’t know

B. If mother stayed over 1 week, what was the teason for staying that long?

C. About how long did the baby stay in the hosp;al?

t u I week or less 2 u 1-2 weeks s u Over 2 weeks 4 u Don’t know

D. If the baby stayed o_v~r 1 week, what waa the reason for staying that long?

G. ABOUT HOW MANY POUNDS DID THE BABY WEIGH AT BIRTH?

I u Under 5 2 m 5-10 3 I_J Over 10 4 u Don’t know

8. WAS THERE ANYTHING UNUSUAL OR WAS ANYTHING WRONG WITH THE BABY WHEN HE( SHE) WAS BORN?

I n Yes 2uN0 s u Don’t know

IF YES:

A. What was the. matter?

B. What did the doctor say caused this?

9. WHILE YOU (THE MOTHER) WERE PREGNANT WITH THIS CHILD DID YOU HAVE ANY MEDICAL PROBLE&IS

OR COMPLICATIONS?

I a Yes 2 UNO 3 0 “Don’t know

IF YES, what kind of trouble did you have?

41
(27)

(31)

(34)

(36)

(37)

11. BEFORE THIS BABY WAS BORN, WHILE YOU (THE MOTHER) WERE PREGNANT-WITH THIS CHILD, DID YOU

(THE MOTHER) SEE A DOCTOR?

I I_J Yes 20N0 3 0 Don’t know

IF YES:

A. About how many months pregnant were you when you first saw a doctor?

1 u Less than 3 2a3t06 3 D Over 6 4 0 Don’t know

B. About how many times altogether did you see a doctor while you (the mother) were pregnant?

t u None 2nlto3 3 m 4 or more d u Don’t know

12. DID YOU (THE MOTHER) HAVE ANY TROUBLE WITH THE PREGNANCY OR BIRTH OF THIS CHILD?

f n Yes 2uNo 3 u Don’t know

IF YES, what was the trouble?

15. W–AS THE CHILD BREAST FED?

i m Yes 2uN0 3 u Don’t know

A. IF YES, for about how many months was he(she) breast fed?

1 u Less than 1 znlto6 3 0 Over 6 q u Don’t know

B. When breast feeding was stopped, how easily did the baby accept the change?

1 u No problem 2 D Some problem 3 U Considerable problem

16. ABOUT HOW OLDWAS THE CHILD WHEN HE(SHE) FIRST WALKED BY HIMSELF?

i u Under 1 year old z U Between 1 and l% years old

3 ~ Over 1%’ years old q u Don’t know

17, AEGJT HOW OLD WAS THE CHILD WHEN HE(SHE) SPOKE HIS FIRST REAL WORD?

I n Under I year old 2 u Between 1 and llA years old

3 U Over 1% years old A u Don’t know

la. CHILDREN LEARN TO CO THINGS LIKE EATING BY THEMSELVES AND TALKING AT DIFFERENT AGES. DO

YOU THINK THIS CHILD WAS ESPECIALLY ~ IN LEARNING TO DO THINGS, ABOUT AvER AGE, OR SOMEWHAT SLOWER THAN OTHER CHILDREN?

I U Faster than other children 2 u About the same 3 a Slower d u E@n’t know

19. DID HE(SHE) GO TO KINDERGARTEN OR NURSERY SCHOOL BEFORE ENTERING THE FIRST GRADE?

I O Yes 2~No s o Don’t know

32. HERE IS A LIST OF DISEASES THAT CHILDREN SOMETIMES HAVE. HAS THIS CHILD EVER HAD:

If yes, about how

old at the time?

H. Epilepsy? 1 Cl yes+ Age_ 2uN0 3 ❑ Don ‘t know

J. Cerebral palsey? i n Yes+- Age 2uN0 3 u Don’t know

,

35. HERE ARE SOME OTHER KINDS OF ILLNESSES OR CONDITIONS SOME CHILDREN HAVE. HAS YOUR CHILD

EVER HAD:

E. A heart murmur?

F. Anything wrong with

his(her) heart?

t I_J Yes 2uN0 s o Don’t kaow

i D Yes 2uN0 s o Don’t know

42 *US. GOVERNMENTPRINTINQOFFICE: 1977-260.937:28
Series 1.

Series 2.

Series 3.

S6n+es 4.

Series 10.

Series 11.

Series 12.

Series 13.

Sw”es 14.

Sa+es 20.

Series 21.

S-”es 22.

VITAL AND HEALTH STATISTICS PUBLICATION SERIES

Formerly PublicHealth Service PubliaetionNo. 1000

Prognams and collectwn procedures. —Reports which describe the general programs of the National

Center for Health Statistics and its offices and divisions, data collection methods used, definitions,

and other material necessary for understanding the data.

LMta evaluation and methods research. - Studies of new statistical methodology including: experimental tests of new sttrvey methods, studies of vital statistics collection methods, new analytical

techniques, objective evaluations of reliability of collected data, contributions to statistical theory.

Artalvtical studies. -Reports presenting analytical or interpretive studies based on vital and health

statistics, carry$ig the analysis further than the expository types of reporta in the other series.

Documents and committee reports.— Final reports of major committees concerned with vital and

health statistics, and documents such as recommended model vital registration laws and revised

Mrth and death certificates.

Data j%rn the Health Interv&w Survev. —Statistics on illness, accidental injuries, disability, use

of hospftal, medical, dental, and other services, and other health-related topics, based on data

collected in a continuing national household fnterview survey.

Data from the Health Examination Survey. —Data from direct examination, testing, and measurement of national samples of the civilian, noninstitutional population provide the basis for two types

of repcwts: (1) estimates of the medically defined prevalence of specific diseases in the United

States and the distributions of the population with respect to physical, physiological, and psychological characteristics; and (2) analysis of relationships among the various measurements without

reference to an explicit finite universe of persons.

LWa J&om the Institutional Populatwn Surveys. —Statistics relating to the health characteristics of

persons in institutions, and their medical, nursing, and personal care r~eived, based on national

samples of establishments providing these services and samples of the residenta or patients.

DUti @om the Hospital Discharge Survey. —Statistics relating to discharged patienta in short-stay

hospital% based on a sample of patient records in a national sample of hospitals.

DOta on health resources: man#owr and facilities. —Statistics on the numbers, geographic distribution, and characteristics of health resources including physicians, dentists, nurses, other health

occupations, hospitals, nursing homes, and outpatient facilities.

Data on mortality. —Various statistics on mortality other than as included in regular annual or

monthly reports-special analyses by cause of death, age, and other demographic variables, also

geographic and time series analyses.

Data on natality, marriage, and divorce. —Various statistics on natality, marriage, and divorce

other than as included in regular annual or monthly reports-pecial analyses by demographic

variables, also geographic and tfme series analyses, studies of fertility.

Data from the National Natdity and Mortality Surveys. — Statistics on characteristics of births

and deaths not available from the vital records, based on sample surveys stemming from these

records, including such topics as mortality by socioeconomic class, hospital experience in the

last year of life, medfcal care during pregnancy, health insurance coverage, etc.

* For a list of titles of reports published in these series, write to: Office of Information

,. National Center for Health Statistics

Public Health Service, HIU4

Hyattsville, Md. 20782