62 . WAIS Digit-Symbol
(Exp. Adm.)
60 4
58 4
rm cold
56 4
547 ee
524
Age Group 2a < 25-29 30-34 35-39 40 & >
N 30 90 42 au 22
Mean 58.8 58.6 61.6 53.5 53.4
s.D. 8.4 9.2 9.6 9.7 10.1
‘Test by Age Group for 205 ATC Ss Experimentally

Figure 8. Mean Scores

on the WAIS D-S
Tested at Time of Ent

ry into Academy ‘Training.
older and 85-89 are signifi-

ores of the Ss in age groups 40 0

25-29, and 30-34.)

an performance SC

(Note: The mes
he means of the Ss h

cantly lower than

in the groups aged 24 or younger,

CAML symbol-Digit

Ficure 9. Mean Scores 0
perimentally U
nee scores of SS aged

(Note: ‘The mean performal
4 24 or younger,

of the Ss in each of the groups age

22

n CAMI S-D Test py Age Grow
pon Entry into Academy ‘Training.

38
. . (Exp. Adm.
—_ oN °
36 .
34-4 re 7616
324
30
Age Group Me < 25429 30-34 35-39 40 &>
N 83 198 89 49 49
Mean 36.9 36.4 37.4 35.8 3202
s.D. 5.7 604 6.8 7.1 6.4
up for 468 ATC Ss Who Took the Test Ex-

40 or older is significantly lower than the means

25-29, 30-34, and 35-39.)

7


16 [J Passed atc Training Course

| | Failed or Withdrew in
bo Non-failing Status
4 Total N of 88 (67 Enr., 21 Terminals)
10-4
4
4 8.8
4 6
5
J 3.3
J 2 2
4
Chr, Age 22 23 25 29 31 33 35 37 39 4 45
&< 924 -26 -28 -30 932 "34 36 938 -40 942-44 & >
Enr, Pass 3 2 4 5 6 12 5 5 4 3 3 2 1
Enr, Fail 2 3 3 2 1
Enr. W/D 1
Terml. Pass 1 2 2 2 4 2 1 2 2 1 1
Terml, Fail 1

Ficure 5. Age Distribution for 88 ATC Trainees Selected on the Basis of Age for Establishment of a “Non-skewed”
Sample With Which to Determine the Relationships Between Age and Five Measures of Performance on the Of-
ficial, Field-Administered, CSC-ATC-Aptitude Screening Battery.

12


68 Press Test Part IIT
. ——~_@- Adm.)
64
—_
60
r= -.03
567
52
48
Age Group 24&< 25-29 30-34 35-39 40 & >
N 16 51 20 8 5
Mean 61.1 61.6 67.2 64.8 50.7
S.D. 9.4 12.5 9.9 6.4 8.2

Ficurs 14, Mean Performance Scores on Part III of the Press Test by Age Group for 100 ATC
‘Trainees Who Took the Test Experimentally.

(Note: The mean score for the Ss aged 40 & older is significantly lower than the group
means for Ss 24 and younger, 30-34, and 35-39.)

Brown-Carlsen Listening
52 . Comprehension Test
a —. (Exp. Adm.)
50
re 7.16
48
46 NN
44
Age Group 24&< 25-29 30-34 35-39 40 & >
N 21 74 28 12 9
Mean 50.9 51.9 50.5 46.8 45.1
sD. 5.9 6.8 6.9 8.2 9.7

Ficure 15. Mean Performance Scores on the Brown-Carlsen Listening Comprehension Test
(Parts A, B, C, D & E Combined) for 144 Ss Experimentally ‘Tested at Time of Entry into
Academy ATC Training.

(Note: The mean scores of the Ss aged 40 and older and those 35 to 89 are significantly
lower than the mean for Ss aged 25 to 29.)

26


their initial training course compared to a failure
rate of only 33 per cent for the 570 younger stu-
dents, and (b) that the older men who did pass
the Academy also tended to experience greater
difficulty than their younger colleagues in subse-
quent phases of on-the-job training. The con-
sensus that older controllers generally perform
their duties less effectively than younger ATCSs
is supported by the results of several studies,’ 1” *®
all of which indicate that performance, as eval-
uated by supervisors or peers, is apt to decline
after age 40—regardless of tenure or experience
in ATC work. The FAA has submitted for con-
gressional consideration proposals whereby age
would be used as a discriminating factor in the
selection of recruits for ATC training. Under
one such proposal, eligibility for appointment to
ATCS training would require that an applicant
with highly specialized pre-FAA ATC-related
experience be no older than 35 and, if lacking
such qualifying experience, to be 30 or younger.
Although not intentionally designed to do so, the
test battery currently used in the aptitude screen-
ing of most applicants has also been found (as
will be described later) to have considerable po-
tential in screening from eligibility many of the
older applicants, particularly those of age 40 and
over. These and other findings have prompted
the FAA to maintain continuing interest and
participation in research on aging effects,

©. ATC Trainee Selection Standards. Since
1960 much of the research conducted by the Psy-
chology Laboratory of the Civil Aeromedical
Institute (CAMI) has focused upon the iden-
tification of factors associated with measures of
training performance and job proficiency ratings
of ATC personnel.

One of the early CAMI objectives was achieved
in 1963 when a series of analyses and follow-up
studies illustrated that a composite score based
on six of 27 experimentally administered apti-
tude tests could have been used to accurately
forecast the pass-fail status of approximately 70
per cent of 893 students who enrolled in the
Academy’s basic ATC training courses during
August 1961 through March 1963. These find-
ings prompted a revision in ATC selection
procedures. Beginning in January 1964 and
continuing through October 1968, a qualifying
aptitude index, based on the six tests, constituted
a major eligibility requirement of every appli-

cant regardless of pre-FAA experience and other
qualifications.

About six months prior to implementation of
aptitude screening procedures, however, budg-
etary limitations necessitated a drastic reduction
in the recruitment of ATC personnel and also
discontinuance of the standardidzed basic train-
ing courses at the Academy. The initial training
of each new recruit became the responsibility of
officials at the recruit’s facility of assignment.
Such decentralization of training also resulted in
termination of CAMI’s experimental testing and
validation program. These conditions prevailed
for almost half a decade, The few hundred men
appointed to training each year were usually se-
lected from among those applicants having both
the higher aptitude test scores and greater
amounts of ATC-related experience. However,
they were not sufficient in number to offset per-
sonnel losses and ensure proper growth of the
system.

In 1968, the President announced the need for
rapid expansion of the air traffic management
system and a new program of accelerated re-
cruitment and traiining of control personnel was
begun. Under the new selection standards,
which became operational in November of 1968,
an applicant having an exceptional amount or
type of pre-FAA ATC-related experience could
be granted an exemption of the aptitude quali-
fication requirement. It was assumed that such
highly experienced individuals, after completion
of basic training in FAA procedures, would be
able to master subsequent phases of training more
rapidly and advance to journeyman status more
quickly than the less experienced men. With
minor exceptions, the selection standards for all
other applicants remained essentially the same as
those employed during the preceding four years
and ten months. Training policies, however,
were revised. Basic training courses, similar to
those conducted prior to 1964, were again insti-
tuted at the Academy and the subsequent avail-
ability of training-school grades for use as cri-
teria led to a resumption of CAMI’s research and
development efforts to improve further ATC se-
lection methods.

The FAA’s ATC selection-and-screening pro-
grams of various time periods have differed in
some respect; yet, they have been remarkably
similar. The selection process has always in-
eluded consideration of an applicant’s pre-em-



similar age range reported a correlation of —.42
between age and performance on the WAIS
Digit-to-Symbol subtest; this coefficient, which
compares favorably with the —.46 obtained by
Birren and Morrison, was among the highest of
those they obtained for a variety of measures.
In the present study, a corresponding coefficient
of —.19 was obtained. A coefficient of such mag-
nitude, if derived on a larger sample in which
age was more normally distributed and covering
a greater range, would reflect an inverse rela-
tionship of moderate intensity only. However,
it should again be emphasized that this sample,
like those for which performance data on the
other tests were collected, included no men be-
yond 52 years of age and, of those subjects within
the restricted range, relatively few were over 40.
In fact, age was so abnormally distributed that
the authors questioned the appropriateness, or
legitimacy, of applying correlational formulae
to the data. The correlations were computed,
however, because it was felt that each coefficient,
together with the graphically depicted results
would be useful.in establishing and projecting
general trends in the relationship between age
and performance. Also, inasmuch as the experi-
mentally administered batteries included several
CSC subtests, it was assumed that correlation
coefficients computed by the same method as those
in the first phase of the study would be useful
for comparative purposes and also illustrate the
attenuation effects.

Formulas are available with which to adjust
correlation coefficients for restriction-of-range
effects, provided the data conform to certain con-
ditions.*** For example, if the correlation of
—.19 between age and the WAIS D-S scores had
been found for a sample in which the ages were
normally distributed within a range of 20 to 40,
statistical procedures could then have been ap-
plied to obtain an estimated correlation of ap-
proximately —.36 for a sample in which age
was normally distributed within a range of 20 to
60. In each instance, however, the reliability of
the estimate would partially depend upon the
degree of normality in the distribution of the
variables actually being dealt with. Inasmuch
as the ages of the examinees of all 16 samples
were known to be abnormally distributed, no
estimates in this respect were attempted. Never-
theless, it is important to bear in mind that each
correlation involving age and listed as being sta-

23

tistically significant would undoubtedly have
been of considerably greater magnitude if based
on samples in which age was normally dis-
tributed over a greater range.

Figure 9 presents the plotted means by age
group for the CAMI Symbol-to-Digit Test. This
test is a counterpart of the WAIS Digit-to-
Symbol Test in that it involves decoding rather
than encoding. It is also a more highly speeded
test. Although the subjects of the age groups
“35 to 39” and “40 & older” performed less well
than the younger groups, only the mean per-
formance of those over 39 was found to be sig-
nificantly lower.

C. The Four CTMM Subtests, Press Test, and
Listening Comprehension. Figure 10 pertains to
CTMM Subtest 7, Figure Analogies. The graph
reveals that the youngest group performed best
on this test and that the performance means were
progressively lower, with one minor exception,
for each succeeding age group. Most of the dif-
ferences were statistically significant. On CTMM
Inferences (see Figure 11), the trainees over age
39 performed at a significantly lower level than
all younger groups, but differences among the
latter were nonsignificant.

In Figure 12, the successive decline in the
plotted means from the youngest to the oldest.
group illustrates the potential with which CTMM
Coins, or a similar test, might be used in the
screening of older applicants for ATC training.
The performance means of both older groups
differed markedly, and significantly, from those
of the two youngest groups. It may also be re-
called that the scores on CTMM Coins correlated
45 with the overall measure of training course
performance; this validity coefficient was higher
than that obtained with any other test.

Figures 13 and 14 seem to warrant no special
comment. Proceeding to Figure 15, it should
first be noted that only 12 trainees of age 35 to
39 and only nine subjects of age 40 and above
were administered the five-part Brown Carlsen
Listening Comprehension Test. In each instance,
however, their mean performance level was ap-
preciably below that of the younger groups.

D. CAMI Directional Headings. The results
for the three parts of the CAMI-developed Di-
rectional Headings Test are depicted in Figures
16, 17, and 18. Each part of the test is relatively
simple but very highly speeded. Through use



46 Directional Headings Test

Part III (Exp. Adm.)
42 4 a ~

>

38
r= 7.22
34 4 a
30 4
Age Group 24&< 25-29 30-34 35-39 40 & >
N 8 41 13 9 15
Mean 44.1 40.8 39.0 31.8 35.0
s.D. 20.9 12.9 11.6 16.9 13.6

Fieure 18. Mean Scores on Directional Headings Test Part III by Age Group for 86 ATC
Trainees Who Took the Test Experimentally,

(Note: No differences between group means are significant.)

28 Locating Data Test

. (Exp. Adm.)
27 a
26 a

25

24 re-.19

23 —TM—.

22 +
Age Group 24&< 25-29 30°34 35-39 40&>
N 38 143 57 37 38
Mean 25.3 26.5 27.4 23.6 23.0
S.D. 5.8 4.9 6.1 5.3 5.4

Frieurr 19. Mean Scores on Locating Data Test by Age Group for 818 Students Who Were
Administered the Test on an Experimental Basis at Time of Entry into Academy ATC
‘Training.

(Note: The mean performance scores of the Ss 35-39 years old and those 40 or over are
significantly lower than the means of Ss in age groups 25-29 and 30-34. Other differences
are non-significant.)

29



CTMM Subtest 10, Coins

9 — (Exper. Administered)

8 _—_——_.,

7

r= -.29 .

6 ——.

5
Age Group wa< 25-29 30-34 35-39 40 & >
N 27 83 42 15 7
Mean 8.8 8.0 7.8 6.3 5.9
S.D. 2.7 2.6 3.5 3.0 2.6

Ficure 12, Mean Scores on CTMM Coins Test by Age Group for 184 ATC Students Who
Were Experimentally Tested at Time of Entry into Academy Training.

(Note: The mean performance scores of Ss in groups aged 35-39 and 40 or older are each
significantly lower than either mean for Ss in age groups 25-29 or 24 and younger.)

CTMM Subtest 11, Arithmetic

10 (Experiment, Administered)

9

3 _— TM_.

7 re -.16

6
‘Age Group 2&< 25-29 30-34. 35-39 OB >
N 19 70 31 12 12
Mean 9.3 7.9 8.4 7.9 6.6
S.D. 1.5 2.7 2.5 3.2 2.5

Ficure 13. Mean Scores on CTMM Arithmetic ‘Test by Age Group for 144 ATC Trainees Who
Were Administered the Test on an Experimental Basis.

(Note: The mean performance scores of Ss in each of the groups aged 35-39 and 40 or
older are significantly lower than the mean of Ss in age group 24 or younger.)

25



chronological age are presented in Table II. Sub-
test 24, “Computations,” which is also sometimes
referred to as “Number Facility,” is the only one
which correlated positively with age, Its magni-
tude was only .09. Corresponding coefficients for
the other four were: —.14 for CSC 540 (Air
Traffic Problems) ; —.84 for CSC 51 (Space Re-
lations); —.32 for CSC 135 (Following Oral
Directions) ; and ~.34 for CSC 157 (Abstract
Reasoning and Letter Sequence). The latter
three were statistically significant (p<.01),
while those pertaining to CSC 24 and CSC 540
were not significant.

The CSC Total Score (as derived opera-
tionally) correlated —.35 with age. A coefficient
of this size for a sample of only 88 cases is sig-
nificant at the .01 level. Moreover, the results
of a multiple regression analysis, in which age
was retained as the criterion variable, indicated
that a validity coefficient of —.42 could be ob-
tained with a composite score based on omission
of performance data for both CSC 24 and CSC
540 and application of specific factor weights
(other than those dictated for operational use)
to the scores on CSC Booklets 51, 135 and 157.
Also, an extension of this multiple regression
analysis revealed that if the latter three sub-
tests were supplemented by Laboratory Grade
Average, and if weights as determined in the
analysis were applied to the four measures, the
resulting composite measure would have cor-
related —.48 with chronological age. This co-
efficient was viewed as being relatively high
because (1) the age range, of 22 to 49, was so
small and (2) there was no reason to doubt that
factors other than those associative with age were
also operating in determining performance on
the tests and on the laboratory training problems.

8. Validities of CSC test measures. When the
Academic Grade Average was considered as the
criterion variable, the five subscores and the
Total CSC Test Score yielded low and non-
significant validities—four of which were nega-
tive. However, three subtests and the CSC Total
Score emerged as significant predictors of Labo-
ratory Grade Average, In this respect, the cor-
relations were: .83 for CSC 185; .38 for the com-
bined parts of Booklet 157; .27 for CSC 540;
and .83 for the composite score. Although not
presented in the table, the results of a regression
analysis indicated that if factor weights as de-
termined by the regression were applied to the

16

scores on Booklets 157, 135 and 540, the resulting
composite scores would correlate 43 with the
variable reflecting laboratory performance.

Differences between the validities of the tests
for the two summary measures of training per-
formance were much greater than expected.
However, the Academic Grade Average cor-
related .10 with Laboratory Grade Average and
this was considerably lower than had been antici-
pated. Unpublished analyses involving the Acad-
emy training classes of 1961 through 1963 had
resulted in correlations ranging from .47 to .63
between variables of the same name and general
type. A question regarding the possibility of
“sampling error” therefore arose when a recheck
proved the coefficient of .10 to be correct for the
sample of 88 cases. This prompted determina-
tion of the corresponding correlation for the en-
tire group of highly experienced trainees. The
resulting coefficient of 21 was significantly
higher than the .10 obtained for the sample, yet
significantly lower than any of the correlations
based on inputs of earlier years. Moreover. ad-
ditional analyses pertaining to the groups in-
volved in the present study revealed that the
variance of the Laboratory Grade Averages was
more than twice that of the Academic Grade
Averages. This and other findings suggest that
the Academic Grade Averages probably possess
less potential than the Laboratory Grades for
purposes of individual differentiation and, if so,
would partially explain why the aptitude tests
are more useful for the prediction of laboratory
performance than academic achievement.

The validities of the various CSC Test meas-
ures are also shown in Table III. Adjacent to
each of the first-order, or original, validity co-
efficients is one of second order representing the
remaining validity of the aptitude measure after
statistically partialing out the variance associa-
tive with age. Inasmuch as the initial validities
of all subtests for prediction of the Academic
Grade Average were quite nominal, attention
should be directed to a comparison of the two
coefficients obtained for each variable when the
Laboratory Grade Average served as the cri-
terion. The validity of CSC 135, which was
originally .33, dropped to 20. Similarly, the co-
efficient of .88 for CSC 157 was replaced by a
24, and CSC 540, which had an initial validity
of .27 yielded a coefficient of .20 after partialing
out the effects of age. Although the residual


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authors advance the theory that the results are
an outgrowth of interaction effects of age and
length of experience in military control work.
The performance means of the two oldest groups
differed significantly from that of the group aged
30-34; all other differences were nonsignificant.

On CSC 135 Oral Directions, the highest mean
score was for the youngest group and, although
each older group performed at a successively
lower level, the greatest difference between con-
tiguous groups involved the trainees of age 35-39
and the oldest group (see Figure 21). In fact,
the mean score of the trainees aged 40 and above
was significantly lower than the means of all
younger groups.

G. Abstract Reasoning and Letter Sequence.
Performance measures on both parts of CSC
Booklet 157 were also negatively related to
chronological age. Figure 22 reveals that the
youngest group performed better on Abstract
Reasoning than any other group, and that the
examinees aged “35 to 39” and those over 39
experienced considerable difficulty. Many of the
differences involving the two oldest versus the
three youngest groups were statistically signifi-
cant.

The group means shown in Figure 23 for the
Letter Sequence portion of CSC 157 reflect a
consistent and moderate decline in performance
from the youngest to the oldest group of trainees.
Although the correlation of —.15 between age
and this aptitude measure is statistically signifi-
cant, it is not as great as implied by the slope of
the plotted means. However, only one difference
proved to be statistically significant; it was be-
tween the youngest and oldest groups.

IV. Summary.

The results obtained in this study consistently
demonstrate that ATC trainees over 34 years of
age tend to perform less well than their younger
colleagues on a variety of paper-and-pencil apti-
tude tests. This investigation, in agreement with
previous findings” **1° has also shown chrono-
logical age to be significantly and inversely re-
lated to measures reflecting performance in the
prescribed courses of basic training.

Although the subjects over age 34 represented
only about 23 per cent of the 710 men involved
in the entire study, their failure rate (31.1 per
cent) in Academy ATC training was about three

32

times that of the younger trainees. For the 88
subjects selected to constitute a “normalized”
sample in terms of age, correlation of —.31 was
obtained between the overall Academic+ Lab-
oratory Grade Average and age. Previous re-
search,!? 481° based on samples in which age was
not a selection factor, has shown age to cor-
relate as high as —.38, and no lower than —.25,
with a similar criterion measure.

The analyses accomplished in the first phase of
the present study on the operationally-reported
CSC ATC Aptitude Screening Test scores re-
vealed that chronological age was negatively re-
lated to four of the five subtest measures and
with the composite CSC Test score. Only one
of the negative coefficients, the —.14 obtained
for CSC 540, failed to be statistically significant.
In the second phase, in which 14 different apti-
tude tests were administered on an experimental
basis to subgroups of the 710 subjects, age was
found to be negatively correlated with every per-
formance measure, and in most instances, at a
statistically significant level.

Based on successive examination and compari-
son of the mean performance scores of the sub-
jects by age group on each of the various aptitude
tests, there seems to be considerable evidence that,
trainees over age 34 are apt to perform less well
than their younger classmates. Beyond age 40,
these age-related decrements are likely to be even
more pronounced.

All of the experimentally-administered tests, as
well as most subtests of the operational screening
battery, yielded substantial validities for predic-
tion of training performance. Most notable in
this respect were the following: CTMM Coins
with a validity coefficient of 45; the WAIS
Digit-to-Symbol subtest (r=.37); CTMM In-
ferences (r=.37); and CTMM Arithmetic
(r=.87). The third part of the Press Test,
CAMI Locating Data, and the Directional Head-
ings Test also correlated appreciably with the
overall measure of training performance. Such
findings suggest the feasibility with which these
or similar tests might be used in conjunction
with some, or all, of the subtests of the CSC
battery to further improve ATC-trainee selection
procedures.

The findings pertaining to age in this study
are pervaded by attenuation effects (the age
range was 21-52 years and only 79 of the 710
trainees was over 40), and one may only specu-


IL. Method.

A. Testing Sessions. Thirty-one testing ses-
sions, involving 16 of 17 incoming Enroute
classes and 15 of 17 Terminal groups, were con-
ducted during the period 20 November 1968
through 27 March 1970. Because of holiday
travel conflicts, three classes of trainees were ex-
cluded from the experimental testing program.
A total of 2,533 Enroute trainees and 664 Term-
inal students were examined. However, only
444 (or 17.5 per cent) of the Enroute examinees
and 244 (36.7 per cent) of the Terminal partici-
pants possessed higher-than-normal pay grades.
Among the 444 Enroutes, there were 29 GS-8’s,
412 GS-9’s, one GS-10 and two GS-i1’s. The
Terminal examinees represented 15 GS-8’s, 212
GS-9’s, two GS-10’s, 14 GS-11’s and one GS-12.
Aside from these 688 trainees (i.e., 444 plus 244),
an additional 22 men of higher-than-normal pay
grades entered either the Enroute or Terminal
course during this period but were not examined
because of illness or tardiness in arriving and
enrolling with their scheduled class.

No more than three hours could be allocated
for each testing session and adherence to training
schedules precluded more than one session per
class or group. Inasmuch as the overall project
(of which this study is but a part) specified that
the predictive potential of many different types
of aptitude tests be explored, the groups of tests
selected for experimental administration were in-
tentionally varied. At least one week, and some-
times two, intervened between the incoming and
alternating Enroute and Terminal classes. Each
incoming class was usually administered only
five to seven instruments but periodic modifica-
tion of the battery ultimately resulted in the
collection of response data on samples of dif-
ferent size for 14 different tests.

B. The Present Sample. Exclusive of overlap,
the present sample involves a total of 710 men
and represents all students who entered the
Academy’s basic courses with higher-than-normal
pay grades during the period 20 November 1968
through 27 March 1970. Of these, 446 (about 63
per cent) were enrollees of the Academy’s 8-week
Enroute “T-202” basic training course. The in-
struction and laboratory problems provided in
this course were oriented toward the work re-
quired of a controller at an Air Route Traffic
Control Center (ARTCC). The remaining 264

were airport tower personnel who took the Term-
inal, or T-203, 8-week course. The latter was
similar to that designed for Center personnel
but focused upon basic training in Terminal
Area Traffic Control (“TATC”) procedures.

C. Procedure. CAMI researchers administered
no more than seven aptitude tests to any of the
incoming classes which included higher-graded
ATC trainees. However, examination of the
records subsequently received by CAMI revealed
that 301 of the 710 trainees of grades GS-8 and
above had been administered the operational
screening battery although their ATC-related ex-
perience was ultimately deemed sufficient to war-
rant exemption of the aptitude requirement,

Two investigative approaches were therefore
adopted. In the first, a series of analyses were
undertaken to determine the interrelationships of
age, training grades, and the field-reported CSC
Test scores for the group of 301 subjects. The
second phase of the study pertained only to those
samples experimentally tested by CAMI per-
sonnel.

The ages of the 301 operatioally examined
men, although ranging from 21 to 49 years,
yielded a distribution which was markedly
skewed—in a positive direction. It was recog-
nized that some of the scheduled correlational
analyses would produce more reliable and mean-
ingful results if accomplished on a more “nor-
malized,” though appreciably smaller, sample.
The age range for the group was therefore di-
vided to establish 13 intervals and attempts were
then made to select randomly the cases for each
interval in accordance with the proportions dic-
tated by a normal curve of distribution. Since
relatively few of the 301 controllers were over
age 40, randomness in the selection process was
not always possible and considerable difficulty
was encountered in attempts to obtain the precise
and proportionate numbers of cases desired for
the various age brackets. Nevertheless, a sample
of 88 cases was established which, though smaller
than originally anticipated, appeared sufficiently
free of skewnes to permit the valid assessment of
the interrelationships of chronological age, part
scores and composite scoress on the CSC ATC
Test, and training-course performance measures.

After establishing the intercorrelations of all
variables for the special sample of 88 cases, a
series of multivariate correlational analyses,



ployment experience, his educational background,
the outcomes of an interview with management
officials, and the results of a medical examination.
Previous relevant experience, particularly as a
military controller, has consistently been viewed
as an important asset.

Although the FAA continues to select the ma-
jority of its ATC trainees from an applicant pool
of former military air traffic controllers, most
such applicants usually lack sufficient experience
to warrant exemption of the aptitude require-
ment. Consequently, about two-thirds of all the
selectees are moderately experienced men who
have attained qualifying scores on the battery of
aptitude-screening tests. They are normally
hired at a pay grade, or General Service level, of
GS-7. Approximately seven per cent, who
possess little or no related experience, are selected
primarily on the basis of aptitude tests scores
and/or educational background and are generally
assigned an entry grade of GS-5 or GS-6. Since
November 1968, less than one-fourth of the en-
trants into FAA ATC training have qualified
under the standards whereby highly specialized
experience has not only permitted exemption of
the aptitude requirement but also appointment to
training at the GS-8 level or higher. In most
instances, they have been appointed as GS-9
trainees.

The six tests currently employed in the apti-
tude screening of most applicants for ATC train-
ing are those which CAMI identified in research
of several years ago as the most valid group for
prediction of training performance. All six are
U. S. Civil Service Commission (CSC) instru-
ments. Operationally, the battery is commonly
referred to as “The CSC ATC Aptitude Screen-
ing Test” and the six parts, which will be de-
scribed in later sections of this report, are re-
ferred to as “subtests.”

D. The Present Study. This report pertains
to only a small portion of a multi-phase research
project which CAMI initiated in November 1968
at the request of the Washington Office of Per-
sonnel. In conjunction with the requested re-
search, various aptitude tests were administered,
on an experimental basis, to all but three of the
successive incoming classes of the Academy’s
basic ATC training courses during the ensuing
17 months. In order to facilitate the research,
the Director of Personnel (PN-1) wrote to all

Regions specifying that CAMI be provided a re-
port on each frainee, at time of entry into the
Academy, reflecting types and amounts of pre-
employment experience, facility of assignment,
the overall eligibility rating, pay grade, and
other information. It was further directed that
the report on each trainee who took the opera-
tional CSC ATC Aptitude Test also include all
part scores and the composite measure of per-
formance.

In accordance with existing policy, the vast,
majority of the trainees arrived at the Aero-
nautical Center for enrollment in either the En-
route or Terminal training course within two
weeks.after being hired by the FAA. Combined
enrollments for the Academy’s two basic ATC
training courses totaled 3,751 for the 17 months
encompassed by the study. Records revealed
that 3,041 (or about 81.1 per cent) of the trainees
entered with pay grades of GS-7 and lower and
only 710 at the GS-8 level or higher, Complete
information reflecting the specific standards by
which each trainee was respectively selected for
appointment to training was not available.
Based on eligibility standards, however, it was
known that al/ of the higher rated trainees pos-
sessed pre-FAA ATC-related experience in excess
of the minimum, thereby warranting exemption
of the aptitude screening requirement. In con-
trast, it was presumed that only a small, though
perhaps significant, proportion of the GS~7’s
possessed enough experience to permit such a
waiver. Almost all other trainees, the majority
of whom were also GS~7’s, entered under stand-
ards which required a qualifying score of at least
210 on the CSC ATC Aptitude Test. For each
of these individuals, the test score and evaluations
of education and all related experience were
weighted in a prescribed manner to derive an
eligibility rating for appointment to ATCS
training at the GS-5, GS-6, or GS-7 level. In
view of the aptitude-screening procedures and
the concomitant attenuation effects, these 3,041
lower-rated trainees were deemed rather inap-
propriate for an investigation of relationships
between chronological age and mental abilities.
Thus, this study focused upon the 710 men who
entered the Academy at the GS-8 level or higher
because it was assumed that research based on
samples drawn from this group would yield
more meaningful results than if accomplished on
samples comprised primarily of aptitude-
screened trainees.


rey

spe

the
it si
betw
men
subts
taine
opere
speci:
the 1}

Tasux IIL—VALIDITIES OF CSC ATC-APTITUDE-SCREENING-TEST MEASURES BEFORE AND AFTER
PARTIALING OUT THE EFFECT OF CHRONOLOGICAL AGE

Academie
Grade Average

Combined
Acad+Lab. Gr. Avg.

Laboratory
Grade Average

Ast ist ist.
Order Partial + © Order = Partial ©=« Order~—S~Partial
r r r r r T

CSC 24 Number Facility —-05 —.03 —.06
—.04 00 —.03

CSC 51 Space Relations —+10 +02 04
— +18 —.08 —.06

CSC 135 Following Oral Dir. —-10 +33** 24
=.138 +20 212

CSC 157 Abst. R. & Ltr. Sq. +02 -38** -33**

—.02 224% +20

CSC 540 Air Traffie Problems. +04 227 +20
02 -20 14
CSC Composite (Total Score) — 08 or -33** i” 225% »

*Significant at less than the « 05 level.
*#ignificant at less than the - 01 level.

Note: The data above are for a
from among 301 students for whom fiel

“normalized” age sample of 88 Enroute and Terminal trainees who were selected
d-administered CSC Test scores were available but who were hired at a level

higher than GS-7 on the basis of pre-FAA ATC-related experience rather than on the basis of test scores.)

validities of these three measures are, in each in-
stance, substantially lower than intially obtained,
they are nevertheless of appreciable magnitude
and one (the 24 for CSC 157) is statistically
significant.

4, Means of CSC subscores by age group. A
graphic summary of the relationships between
age and each of the CSC measures is presented
in Figure 7. An examination of the plotted
mean scores for the subjects by age group reveals
that the data for three of the five subtests and
for the overall test have resulted in highly sim-
jlar configurations, with the mean performance
scores highest for the 23 youngest students and,
with one minor exception, progressively lower
for each of the older groups. However, the
group mean scores for CSC 24 Number Facility
and CSC 540 Air Traffic Problems (ATP) fol-
low a unique pattern. In regard to Number
Facility, the lowest of the group means is for
the youngest trainees and the highest is for the
oldest group. A statistical analysis indicated a
high degree of variance jn the CSC 24 scores
about each of the four group means and, al-

17

though no significant differences were found be-
tween any of the groups, the trend in the plotted
data suggests that the positive relationship be-
tween age and performance on this subtest might
be even greater than that indicated by the pre-
viously established correlation coefficient of .09.

The findings obtained for CSC 540 were
unique in that the trainees of age 40 and older
performed almost as well as the two youngest.
groups, both of which had a mean score of ap-
proximately 32. Although the students aged
35-39 represented the only grossly deviant group
on CSC 540, none of the differences between
group means was stat istically significant.

‘The authors were rather surprised to find a
positive relationship, rather than negative, be-
tween age and performance on CSC 24 as well
as a failure of the plotted means for CSC 540
to reflect a consistent trend (in either direction)
insofar as age was concerned. However, both
these subtests are highly speeded and, even
though the factor content of 540 is somewhat
good performance on either instrument

omnibus,
upon arithmetical skill—

is largely dependent



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37 Directional Headings Test
Part I (Exp. Adm.)

36 4

35  ~ _

34 re -.04

33
Age Group Wee 25229 30-34 35-39 40 & >
N 18 74 26 18 17
Mean 35.7 34.8 34.9 32.8 35.9
S.D. 12,1 10.3 10.0 7.8 8.4

Ficure 16. Mean Scores on Directional Headings Test Part I by Age Group for 153 ATC
Trainees Who Took the Test Experimentally,

(Note: No differences between group means are significant.)

36 4 Directional Headings Test

—_— II (Exp. Adm.)
34 4 : .

32 4 r= -.19
30 4 ‘
2% 4

26
Age Group 24&< 25-29 30-34. «35-39. 40 & >
N 18 14 27 18 17
Mean 34.5 35.3 33.7 26.2 30.6
S.D. 15.3 10.5 11.6 13.3 10.2

Ficure 17. Mean Scores on Directional Headings Test Part II by Age Group for 154 Students
Who Were Administered the Test on an Hxperimental Basis at Time of Entry Into Acad-

emy ATC Training.

(Note: The mean performance level of the Ss 39 years old is significantly lower than
the means of the trainees 25-29 and 30-34 years of age. Other differences are not significant.)

27



TECHNICAL REPORT STANDARD TITLE PAGE

T. Report No. 2. Government Accession No.

FAA~AM-7 1-36

3, Recipient's Catalog No.

4. Title and Subtitle

THE RELATIONSHIP BETWEEN CHRONOLOGICAL AGE AND
APTITUDE TEST MEASURES OF ADVANCED-LEVEL AIR
TRAFFIC CONTROL TRAINEES

5. Report Date

July 1971

6. Performing Organization Code

|
|

7. Author's) Bart B. Cobb, M.S.
Carolyn D. Lay, B.A.
Nancy M, Bourdet, B.A.

8. Performing Organization Report No.

9. Performing Organization Name and Address

FAA Civil Aeromedical Institute
P.O. Box 25082

Oklahoma City, Oklahoma 73125

10. Work Unit No.

V1. Contract or Grant No.

12. Sponsoring Agency Name and Address
Office of Aviation Medicine
Federal Aviation Administration
800 Independence Avenue, S. W.
Washington, D. C. 20590

3. Type of Report and Period Covered

OAM Report

14. Sponsoring Agency Code

15. Supplementary Notes

This research was performed under Tasks AM-C-69*PSY-5, AM-A-70-PSY-23,

and AM-B-71-PSY-23.

16, Abstract

This study examined the interrelationships of age, aptitude measures, and train-
ing performance scores for 710 men who entered basic ATC training at the FAA

Academy during November 1968 through March 1970.
52 years, but less than 12 per cent were over 40.

They ranged in age from 21 to
Most of the subjects were

former military controllers who possessed sufficient prior ATC experience to be
(a) selected for training with an exemption from a qualifying aptitude index,
and (b) appointed to trainee status with higher-than-normal pay grades. Age
correlated negatively with 21 of the 22 aptitude measures and with training

course grades.

On most tests, performance means for subjects over age 34 were

significantly lower than those obtained for the younger trainees, and their
attrition rate for the training course was three times that of their younger

classmates.
with the training grades.

Only one of the 22 aptitude measures failed to correlate positively
The results indicated that greater effectiveness in

screening such applicants could be attained if eligibility standards were
modified to include consideration of both age and aptitudes.

17, Key Words
Air Traffic Control
Selection

18. Distribution Statement
Availability is unlimited.
Ibe released to the National Technical
Age Information Service, Springfield, Virginia

Document may

Aptitude 22151, for sale to the public.
19. Security Classif. (of this report) 20. Security Classif. (of this page) 2. No. of Pages | 22, Price
Unclassified Unclassified 34 $3.00

Form DOT F 1700.7 (s-69)



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10


As shown by the top set of bar graphs in
Figure 2, somewhat greater proportions of the
Enroute students of the age brackets “29 and
younger’ ’and “30 to 34” were in the upper half
of their class than were their older classmates.
Of the Terminal trainees, only 6.3 per cent of
those over age 39 attained A+L Grades above
the median. However, the results obtained for
the remaining portions of the Terminal sample
were variable from age group to age group and
failed to reflect any consistency or trend such as
found for the Enroute sample. When the fre-
quencies based on the respective median A+L
Grades of the two samples were combined, it was
discovered that only 24 per cent of the trainees
aged 40 and older and 36.3 per cent of those 35
to 39 years old were in the upper category com-
pared to approximately 46 per cent of those in
each of the two younger age brackets.

B. The Pre-Tested Sample. The group of 301
trainees for whom operational CSC ATC Test
scores were forwarded was highly similar in
terms of age characteristics to the total group of
710. Figure 8 follows the same format as Figure
1 and presents the distributions of age, together
with training course attrition-graduation status,
for the 219 Enroute and 82 Terminal trainees
known to have been operationally examined. Un-
fortunately, insofar as research purposes were
concerned, the smaller group included only 28 of
the 109 attritions previously found in the total
group of 710. Inasmuch as the 109 represented
15.4 per cent of the larger group, a comparable
attrition rate for the 301 would have resulted in
46 non-graduates, Moreover, only two of the
original 37 Terminal Course failures appeared
in the smaller sample. The investigators were
unable to determine the reasons why such dis-
parities occurred but strongly suspected that
factors other than chance were involved. Al-
though the sample of 301 was not as representa-
tive of the 710 as had been anticipated, it was
decided to proceed with the study as planned.

The relationship between chronological age
and the field-reported CSC Test. performance
scores of the 801 subjects is reflected in Figure 4.
The results depicted in the lower set of bar
graphs for the combined Enroute and Terminal
groups are rather startling. They indicate that
less than 40 per cent of the men in the age

brackets “40 and older” and “35 to 39” attained
composite scores of 210 or higher on the opera-
tional battery. Had these subjects not possessed
highly qualifying experience, the aptitude screen-
ing standards, under which 210 is considered as
the minimum passing score, would have pre-
cluded their eligibility for appointment for ap-
pointment to training. In contrast, over half
of the trainees aged “30 to 34” and “29 and
younger” would have qualified. It has been men-
tioned that during the years 1964 through 1968
a “cutting score” of 190 was used in the screening
of all applicants, regardless of types and levels
of experience. The results shown in Figure 4
further illustrate that over one-third of the
trainees over 34 years of age would not have met
this former, and considerably lower, aptitude
requirement.

C. The “Normalized” Sample. The age dis-
tribution for the special sample of 88 cases,
which was drawn from the group of 301 for
whom CSC Test performance measures were for-
warded, was not entirely free of skewness (see
Figure 5). As explained earlier, however, con-
siderable difficulty was experienced in selecting
many of the cases and the sample represents the
largest that could be obtained without further
deviation from the proportions dictated by a
normal curve of distribution. The youngest man
in the sample was 22, the oldest was 49, and the
mean age was 33.1 years. Although the modal
age bracket, which was “31-32,” included 16 cases,
the entire distribution was somewhat platykurtic
(ie. relatively flat-topped).

Sixty-seven of the 88 were Enroute and 21
were Terminal trainees, The sample included a
total of 13 non-graduates and, as found with the
larger groups from which the sample was drawn,
most of the attritions were over 34 years old.
The youngest of the non-graduates was a 27 year-
old student who was killed in an automobile acci-
dent and was subsequently designated as “a
withdrawal in non-failing status.” The remain-
ing 12 non-graduates, all of whom were classified
as training-course failures, were over age 32. In-
cidentally, it was noted that six of the 12 failures
possessed 10 years or more experience in pre-
FAA ATC work. Although no detailed analysis
of the experience backgrounds was attempted, a
cursory review of the records suggested that less
than five per cent of the 710 men involved in the
entire study had had such lengthy experience.



e

cal

e

we

B

REFERENCES

. Birren, J. E.: he Psychology of Aging, Englewood
Cliffs, New Jersey, Prentice-Hall, Inc., 1964.

. Birren, J. B., and J. Botwinick: The Relation of

Writing Speed to Age and to the Senile Psychoses,

JOURNAL OF CONSULTING PSYCHOLOGY,

16 :309-405, 1951.

Birren, J. E., and D. F. Morrison: Analysis of the

WAIS Subtests in Relation to Age and Education,

JOURNAL OF GERONTOLOGY, 16 :363-869, 1961.

Birren, J. E., and W. Spieth: Age, Response Speed,

and Cardiovascular Functions, JOURNAL OF

GERONTOLOGY, 17 :390-291, 1962.

. Brown, BR. A.: Age and Paced Work, OCCUPA-

TIONAL PSYCHOLOGY, 31:11-20, 1957.

Cobb, B. B.: The Relationships Between Chronologi-

cal Age, Length of Experience, and Job Performance

Ratings of Air Route Traffic Control Specialists.

FAA Office of Aviation Medicine Report No. AM-

67-1, 1967.

. Cobb, B. B.: A Comparative Study of Air Traffic

Trainee Aptitude-Test Measures Involving Navy,

Marine Corps and FAA Controllers. FAA Office of

Aviation Medine Report No. AM-€8-14, 1968.

DuBois, P. H.: Multivariate Correlational Analysis,

New York, Harper & Brothers, 1957.

. Edwards, A. L.: Statistical Methods for the Be-
havioral Sciences, New York, Rinehart & Company,
Ine., 1954.

. Foulds, G. A. and J. ©. Raven: Normal Changes in

the Mental Abilities of Adults as Age Advances,

JOURNAL OF MENTAL SCIENCE, 94:188-142,

1948.

Friend, C. M., and J. P. Zubek: The Effects of Age

on Critical Thinking Ability, JOURNAL OF GER-

ONTOLOGY, 13:410, 1958.

12.

13,

14,

16.

17.

18.

Guilford, J. P.: Fundamental Statistics in Psychology
and Education, York, Pennsylvania, Maple Press
Company, 1956.

Szafran, cited by Welford, A. T.: Ageing and Human
Skill, London, Oxford University Press, 1958.

Talland, G. A.: Human Aging and Behavior, New
York, Academie Press, 1968.

. Thorndike, R. L.: Research Problems and Techniques.

Army Air Forces Aviation Psychology Program Re-
port No. 8, Washington, U.S. Government Printing
Office, 1947.

Trites, D, K.: Problems in Air Traffic Management:
VI. Interaction of Training-Entry Age With Intel-
lectual and Personality Characteristics of Air Traffic
Control Specialists. FAA Office of Aviation Medicine
Report No. AM-65-21, 1965.

Trites, D. K., and B, B. Cobb: Problems in Air
Traffic Management: III. Implications of Age for
‘Training and Job Performance of Air Traffic Con-
trollers. Civil Aeromedical Research Institute Re-
port No. 62-8, FAA, Oklahoma City, Oklahoma, 1962.

Trites, D. K., and B. B. Cobb: Problems in Air
Traffic Management: IV. Comparisons of Pre-
employment, Job-related Experience With Aptitude
Tests as Predictors of Training and Job Perform-
ance of Air Traffic Control Specialists. Civil Aero-
medical Research Institute Report No. 63-31, FAA,
Oklahoma City, Oklahoma, 1963.

. Trites, D, K., and B. B, Cobb: CARI Research on

Air Traffic Control Specialists: Age, Aptitude, and
Experience as Predictors of Performance. Civil
Aeromedical Research Institute, Unnumbered Report.
FAA, Oklahoma City, Oklahoma, 1964.


late regarding the degree to which the findings
based on extended age ranges might have
been even more pronounced. Moreover, all the
trainees possessed considerable pre-FAA ATC-
related experience; most of them were former
military controllers with exxceptional types or
amounts of control experience; all were ap-
pointed to FAA ATC training with higher-than-
normal pay grades, and although many had taken
the operational CSC ATC Aptitude Screening
Test before establishing final eligibility, all of
them presumably qualified under standards
whereby experience warranted exemption of the
aptitude requirement.

These standards under which the trainees were
recruited were predicated on the assumption that
men having specialized experience would gen-
erally possess the aptitudes essential for rapid
advancement in FAA training. Although results
of this study (see Figure 4) indicate that about
45 per cent would have been declared ineligible
for appointment had they been screened with the
CSC Chattery, they nevertheless represented a
rather select group, both in terms of aptitude
levels relative to a general population and in
terms of pre-FAA ATC experience relative to
that characterizing groups of trainees recruited
under conventional standards.

Due to the nature of ATC work and the repeti-
tive involvement of certain perceptual-integra-
tive-mental functions in maintaining temporal
and spacial separation of aircraft, the authors
contend that, if age and other factors were held
constant, experienced controllers would prrobably
peform somewhat better than non-controllers on
specific types of aptitude tests. In other words,
if the effects of age could be legitimately par-
tialed out, a moderate and positive relationship

33

would probably be found between length of con-
trol experience and performance measures on
many tests and particularly on those such as
Numerical Facility, Air Traffic Problems, Lo-
cating Data, and Directional Headings.

In contrast with research regarding the rela-
tionship between age and performance measures
of groups selected from the general population,
the present study has pertained to a specific oc-
cupational group. Moreover, most of the subjects
possessed highly specialized experience and all
were relatively young. Although pervaded by
attenuation effects, the results generally reflect a
consistent negative relationship between age and
the types of aptitudes measured.

V. Conclusion.

In view of the obtained interrelationships of
age, the aptitude measures, and the training per-
formance grades, it may be concluded that
greater effectiveness in the screening and selec-
tion of the highly-experienced applicants for
FAA ATC training could be attained if the
eligibility standards were modified to include
consideration of both age and aptitudes. If
deemed desirable, the findings obtained in this
study could provide the basis for formulation of
a revised aptitude test battery which would
screen from eligibility many of the older appli-
cants—particularly a large proportion of those
over 40 years old. The revised battery would
also be more effective than the current battery in
identifying the potential training failures at all
age levels. It would, in many aspects, be advan-
tageous to reinstate standards whereby a quali-
fying aptitude index would be required of all
applicants, regardless of types and amounts of
prior experience.



based on techniques developed by DuBois,’ were
accomplished to determine the empirical validities
(ie., multiple correlations or “R’s”) of the var-
ious combinations of variables as predictors of
three different measures of training course per-
formance. Similar procedures were applied to
determine the correlation between age and each
of several different composite measures based on
various groupings or combinations of test scores
and/or training grades. The validities of all test
variables with the effects of age partialed out
were also computed. Finally, the relationship
between age and each of the aptitude measures
was assessed by a more conventional technique.
In the latter, coarse grouping procedures were
applied to establish four age categories: “29 &
younger,” “30-34,” “35-39,” and “40 & older.”
The mean performance score and a measure of
variance (s?) were computed by age group for
each variable, tests for homogeniety of variance
were accomplished to determine the choice of
formulae for computation of the Standard Error
of the Difference between the means, and all
group mean differences for each variable were
then tested for statistical significance.?

The second phase of the study, which per-
tained to performance data collected in CAMI’s
experimental testing sessions, involved no multi-
variate correlational analyses. Each of the 14
experimental test variables was dealt with sep-
arately. First, the product-moment correlations
were obtained between every test variable and
chronological age; next, the correlations were
computed between the test variables and an over-
all measure of training course performance; and
finally, procedures were employed, as in the first
phase of the study, to obtain the mean per-
formance scores of subjects by age group and
differences between the group means were then
tested for statistical significance.

III. Results and Discussion.
PHASE I

A. The Entire Sample. The ages of the 710
highly-experienced men who entered ATOS train-
ing at the GS-8 level or above ranged from 21
through 52 years. The vast majority, however,
were relatively young (see Figure 1). Only
seven of the 446 Enroute trainees and seven of
the 264 Terminal trainees were over 44 years of
age. Of the total group of 710, 103 were 24

years of age or younger, 313 were 25-29 years
old and 133 were over 29 but younger than 35.
Students in the remaining, older age brackets
totaled only 161 and represented 22.7 per cent of
the entire sample. However, 50 of these older
students either failed or withdrew from Acad-
emy basic training. Although not shown in
Figure 1, this amonuted to an attrition rate of
about 31 per cent whereas the 59 non-graduates
among the younger, larger group represented an
attrition rate of only 10.8 per cent.

The relationship between chronological age
and training course performance is further illus-
trated in Figure 2. In preparing this figure, all
data pertaining to 21 students who withdrew in
non-failing status were omitted. Although logic
warranted that they be deleted from the analysis,
most of them were relatively young and conse-
quently their exclusion from this phase of the
study served to magnify somewhat further the
findings reflecting an inverse relationship be-
tween age and performance. For example, less
than nine per cent of the Enroute students in
the two categories below age 35 failed, and only
about seven per sent of the Terminal students of
similar age brackets were unable to attain their
basic training certificates. Contrastingly higher
failure rates, ranging from approximately 21 to
40 per cent, were found for the trainees of the
older age brackets.

A variety of measures, other than pass-fail
status, were also available for use as criteria. In
the present study, however, only two summary
measures and/or a derivative of the two were
used. The training records of all graduates tra-
ditionally include an “Academic Grade Average,”
which is the mean of all test grades relating to
materials and classroom instruction, and a “Lab-
oratory Grade Average,” which is a global meas-
ure of performance on all laboratory problems.
For research purposes, an arithmetical mean of
the two averages was also computed for each sub-
ject. A portion of the data presented in Figure
2 pertains to an analysis in which this summary
variable, referred to as the “A-+L Grade,” served
as the criterion. More specifically, the median
A-+L Grade of the non-failing students was de-
termined for the separate Enroute and Terminal
groups and the resulting value was used to
designate “Upper” and “Lower” categories of
training performance.


CTMM Subtest 7, Figure Analogies
8 : (Experimentally Administered)

6 r= 7.16 TM

5
Age Group 2a < 25-29 30-34 35-39 40 & >
N 27 83 42 15 v7
Mean 7.8 6.9 6.5 6.6 5.9
$.D. 2.1 1.9 2.0 2.1 2.4

Frqure 10. Mean Scores on CTMM Figure Analogies Test by Age Group for 184 ATC Trainees
Who Took the Test on an Experimental Basis.

(Note: The mean performance scores of Ss in groups aged 25: 29, 30-84, and 40 or older
are each significantly lower than the mean for Ss in age group 24 or younger. )

CTMM Subtest 8, Inferences
13 4 (Experiment. Administered)
12 4 To
—...
-.29

1 te

10 7 :
Age Group 24&< 25-29 30-34 35°39 40&>
N 27 83 42 15 7
Mean 12.1 12,1 11.9 11.6 10.1
S.D. 1.9 1.5 1.4 2.0 2.9

Froure 11. Mean Scores on CMM Inference Test by Age Group for 184 Students Who Took
the Test Experimentally at Time of Entry into Academy ATC Training.

(Note: The mean performance score of Ss in age group 40 or older is significantly lower
than each of the means for Ss in groups aged 24 or younger, 25-29, and 80-34.)

24.


Csc 540 ATP (Exp. Adm.)
34 7 .
32 4
—_

30

2 4 r= -108 ~

26
lage Group Me< 25-29 30-34 35-939 40 &>
N 45 151 65 45 42
Mean 30.3 30.8 33.7 29.1275
s.D. 10.5 10.7 -12.1.~—«10s1—s1200

Ficure 20 Mean CSC 540 ATP ‘Test Scores by Age Group for 348 ATC Trainees Who Took
the Test Experimentally Upon Entry Into the Academy.

(Note: The mean performance scores of trainees 35-39 years of age and those 40 and
older are significantly lower than that of the group 30-34, Other differences are not statisti-

cally significant.)

08 CSC 135 Oral Directions (Exp. Adm.)
26 —
r= -.23 —

24

22

20 4
Age Group 24 & < 25"29 30°34 35°39 40 & >
N 43 140 55 4 37
Mean 27.2 26.4 25.4 25.2 22.4
s.D. 4.1 5.6 4.7 5.9 5.0

Ficure 21. Mean CSC 135 Oral Directions Test Scores by Age Group for 316 Students ‘Who
Were Administered the ‘Test on an Experimental Basis at Time of Entry Into Academy

ATC Training.
(Note: The mean score of the group 40 and older Is significantly lower than the means of
all younger groups. Other differences are not significant.)

30


that groups of subjects at every age level beyond
40 experienced greater difficulty than the younger
groups at grid-matching or congruency-plotting
tasks under both paced and unpaced conditions.
The Szafran study, which measured the accuracy
with which objects were pitched toward a target
under both “direct-vision” and “mirrored” con-
ditions, yielded no appreciable differences be-
tween age groups when the task was performed
in a straightforward manner. Under conditions
involving a mirror, however, the inaccuracy of all
groups was much greater than before and rose
continuously with age; the largest difference oc-
curred between the age groups “20 to 29” and
*30 to 89.”

In view of all the experimental evidence, it is
now acknowledged that adults of middle age and
older tend to perform less well than young adults
at many different tasks. However, the reasons for
such age-related deficiits have not been fully de-
termined. One of the most commonly accepted
doctrines holds that increasing age is accom-
panied by a trend toward less “flexibility,” more
cautiousness and greater perseveration in certain
tasks but, as Birren points out, the terms “flex-
ibility,” “increased cautiousness” and the like “do
not directly lead to inferences about the mecha-
nisms involved.”? Although Birren himself is
not immune to this criticism, the following ex-
tract from his book, “The Psychology of Aging,”
constitutes an excellent summary regarding some
of the factors presumably bearing upon changes
in performance with increasing age.

The delay of decision sometimes seen in older
people, the time taken to review a stimulus,
and the apparent conservatism in behavior
may not be caused by an increase in the
level of certainty required, Rather the difli-
culty may lie in not being able to attain the
same level of certitude as previously, or as
compared with a younger person. Limita-
tions in perception and intelligence, age dif-
ferences in set or expectations, as well as
changes in drive, motivation, and caution
all interact in providing the psychological
basis for the apparent increased behavioral
rigidity with advancing age.’
B. FAA Interest in Research on Aging Effects.
The interest of the Federal Aviation Administra-

tion in research on aging is not merely incidental.
Many of the abilities and skills which have been

shown to decline with age may be deemed crucial
to satisfactory performance in a number of oc-
cupational specialties within the FAA and par-
ticularly in the job of an Air Traffic Control
Specialist (ATCS). Although ATCS personnel
currently number more than 20,000, the rapid
growth of aviation in recent years has imposed
increasingly heavier traffic loads on both men and
equipment of the operation system. Progressive
improvements in surveillance gear, communica-
tions, and ancillary equipment, supplemented by
changes in control procedures and flight regula-
tions and implementation of improved methods
of selecting and training control personnel have
resulted in a highly efficient air traflic manage-
ment system.

Yet, the job of a typical ATCS continues to be
of a very demanding and critical nature. Main-
tenance of safety in the expeditious flow of air
traffic requires that a controller be resilient to
possible effects of variable work-shift patterns,
maintain a high degree of compatibility with
team or crew members, remain vigilant during
all hours of duty with no susceptibility to laxity
during periods of light traffic, retain his emo-
tional stability when faced with emergency situa-
tions, and always be capable of rendering precise
error-free decisions. In order to maintain pro-
ficiency, a controller must commit to memory
without delay all updated changes in procedures
and, when more advanced types of equipment are
introduced into the system, is frequently re-
quired to undertake additional intensive training.
Situations demanding serious study and learning
pervade the entire career of each controller.
Qualification for appointment to initial, or basic,
ATC training is relatively difficult and of these
selected only about six of every ten can be ex-
pected, on the basis of previous studies, to
complete successfully all prescribed training
phases and attain journeyman status some four to
five years after entry into the FAA.

Training records for groups of ATC personnel
recruited since 1960 and a number of unpublished
studies have consistently revealed a definite re-
lationship between chronological age and attri-
tion probability. In an unpublished six-year
follow-up study conducted by CAMI on 688 sub-
jects (who comprised the successive classes of the
Academy’s basic training courses during August
1961 through March 1963), it was found (a) that
72 per cent of 118 men of age 36 and over failed


Relatively complete training-course perform-
ance records were available for most of the 88
selected cases. Officials submitted no Academic
Grade Average for the Enroute student who had
died. Also, the records of the 12 trainees who
failed were usually incomplete. However, an
Academic Grade Average was submitted for
every student who failed although it was gen-
erally based on a fewer number of grades than
available for each passing student. Similarly,
evaluations of performance on laboratory prob-
lems were sufficient in number to permit deriva-
tion of a Laboratory Grade Average for all but
two of the attritions and the deceased student.
Thus, for each of 85 subjects in the sample, the
A+L Grade represented a simple arithmetical
mean of the two summary measures of perform-
ance. In order to preclude their deletion from
some of the scheduled analyses, each of the two
attritions who lacked a Laboratory Grade Aver-
age was assigned an A+L Grade based on the
Academic Grade Average only.

1. Age and training performance. The rela-
tionships between chronological age and the
different measures of training performance for
the cases of this sample are graphically illus-

trated in Figure 6. Although the total number
of cases within each of the arbitrarily established
age groups is relatively small, the results clearly
indicate that the trainees over 34 years of age
experienced greater difficulty than their younger
colleagues in successfully completing their pre-
scribed training course. None of the 23 trainees
within the age bracket “29 and younger” failed
and only two (i.., 6.9 per cent) of the 29 in the
age group “30 through 34” were attrited. The
relationships between age and the other measures
of training performance were investigated, in
this particular phase, by preparing frequency
distributions of the Academic Grade Averages,
Laboratory Grade Averages and A+L Grades
of all non-failing subjects and, based on the re-
spective median of each array, every student who
passed the course was then successively desig-
nated as being either in the “Upper” or “Lower”
half of the group. Of the trainees under 30
years of age, over 78 per cent were in the upper
half of the distribution of Academic Grade Aver-
ages, 68.2 per cent obtained Laboratory Grade
Averages above the median, and 78.3 per cent
possessed “Upper” A+L Grades. In contrast,
no more than 42 per cent of the trainees in any

Tasiz IL—DESCRIPTION OF CSC-ATC-APTITUDE-SCREENING-TEST VARIABLES

CSC Subtest

Weight

Description

OSC 24
Computations

OSC 51
Spatial Patterns

OSC 135
Following Oral Directions

CSC 157
Abstract Reasoning
and
Letter Sequence

CSC 540

CSC Composite or Total
Weighted Scores

A highly-speeded test of arithmetic skill. The problems involve simple addition,
subtraction, multiplication and division. The aptitude factor is referred to
as “numerical facility.”

A test consisting of two different types of spatial items. In one type, the task
is to identify solid figures that can be made from unfolded patterns. In each
of the other, three different views of an object are presented and the subject
must select the correct object from one of four alternatives.

In this test the subject must listen carefully to orally-presented directions and
information; then discriminate between relevant and irrelevant information
in order to proceed toward the proper solution of a series of simple tasks.

In the “Abstract Reasoning” portion of the booklet, the task is to indicate
which of a series of choices (figures) properly carries out a principle of logical
development exhibited by a sequence of figures. In “Letter Sequence” the
subject must indicate which of a series of letters properly carries out a
principle of logical development exhibited by a sequence of letters.

A highly-speeded test consisting of two parts of thirty items each. In each
part, the subject is presented a flight data display for several aircraft and
must determine whether certain changes in altitude may be directed without
violating a specified time-separation rule.

Sum of the weighted raw scores for each of the five CSC test booklets (i.e.,
six subtests).

13



Tasty I—MEANS, STANDARD DEVIATIONS, INTERCORRELATIONS AND VALIDITIES OF CSC-ATC-
SCREENING TEST SCORES, TRAINING-COURSE PERFORMANCE MEASURES AND CHRONO-

LOGICAL AGE

CSC-51 CSC-135 CSC-157 CSC-540 CSC Overall
CSC-24 Space Fol. Abst. R. ATC Compos- Academic Lab Aecad+ Chron.
Number Rela- Oral ~—Letr. —-Prob- ~—=s ite. = Grade Grade_— Lab Age
Facility tions © Direc- Sq. lems Score Average Average Average
tion
Max. N 88 88 88 88 88 86 85 88 88
Mean 42.7 28.8 27.0 26.5 380.7 210.7 88.1 83.4 85.5 33.1
8.D. 6.7 5.0 5.5 9.3 97 © 34.7 5.6 12.9 8.6 5.8
Intercorrelations and Validities
OSC Subtest
24-Num. F. _ .06 +23 122 -30 42 -.05  --.08 —. 06 +09
5i-Space R. _ 43 40 +16 -60  —.10 02 04.84
135-Oral Dir. _ = 4 -38 +72 —.10 -33 124 =.B2
157-Ab.R. & L _— +34 .87 02 +38 +3300 —.84
540-ATC Prbs. _ 62 04 127 12000 —.14
CSC Total Score wee 08 +33 .250 185
Acad. Grd. Avg. _ +10 B10 =. 11
Lab. Grd. Avg. _ +91 =.88
a BL

Acad + Lab Gr. Av.
Chronolog. Age

R (Multiple correlation) of Specific Combinations of Variables Versus Chronological Age

CSC-135 and CSC-157
CSC-135 and CSC-51

CSC-157 and CSC-51

CSC-157, CSC-51 and CSC-135

CSC-157, CSC-51, CSC-135 and Training-Course Lab Grade Averages

of the older groups were above any of the
medians. Aside from the fact that over two-
thirds of the trainees comprising the youngest
group received above-the-median grades and the
finding that most of the failures were 35 or older,
all other results obtained in this analysis were of
such nature as to suggest: only a moderate inverse
relationship between age and training perform-
ance.

2. Age and performance on CSC subtests.
Table I presents a listing and description of the
subtests which comprise the CSC ATC Aptitude
Screening Test. Operationally, five subscores,
rather than six, are generally reported. This
procedure is followed because CSC Booklet 157
contains both “Abstract Reasoning” and “Letter
Sequence.” These two subtests are quite different
but, inasmuch as they appear in the same booklet
and are both double weighted in derivation of the
total score for the CSC ATC Test, the two per-
formance measures are combined and reported
as a single subscore by Civil Service Commission

15

officials. CAMI investigators, however, have al-
ways chosen to maintain separateness of per-
formance data for these and all other subtests
whenever possible. Such was the case in CAMI’s
previous research wherein the six CSC measures
were identified from among 27 variables as yvield-
the best composite for prediction of training
outcomes.

The factor areas covered by the six CSC sub-
tests overlap considerably with those found in
many of the so-called “I.Q.” tests. In fact, an
unpublished CAMI study involving 200 students
who entered Academy ATC training during
1963, revealed a correlation of .81 between the
Comopsite CSC ATC Score and an “I.Q.” based
on the 12 subtests of the California Test Bureau’s
Test of Mental Maturity (CTMM). However,
the latter was found to be less effective than the
Composite CSC ATC Test Score for prediction
of pass-fail status and training grades.

The intercorrelations and validities of the CSC
ATC Test measures and their relationship to



THE RELATIONSHIP BETWEEN CHRONOLOGICAL AGE AND
APTITUDE TEST MEASURES OF ADVANCED-LEVEL
AIR TRAFFIC CONTROL TRAINEES

I, Introduction.

The present study concerns the interrelation-
ships of chronological age, numerous aptitude test
measures and training-school grades of several
different and overlapping samples of ATC
trainees. Under selection standards which were
instituted in 1968 and because of their highly
specialized pre-employment experience, these men
were not required to qualify on the CSC ATC
Aptitude Screening Test and were appointed to
training with higher-than-usual pay grades.
Since the major focus of this study concerns age
and aptitude measurement, a brief review of ma-
terial pertinent to both factors is presented below.

A. Research on Aging Effects. During the
past 20 years scientific estimates of successively
longer life expectancies for increasingly larger
populations have stimulated psychological re-
search on problems associated with aging. Much
of that research, and particularly that accom-
plished within the last ten years, has been ori-
ented toward establishing the reasons why groups
of older individuals perform less well than young
adults in a variety of tasks ranging from simple
to complex. Considerable evidence supports a
theory which holds that deficits in many areas of
performance are primarily attributable to neuro-
physiological effects of aging and the consequent
reduction in reaction-time capabilities. Findings
also indicate that many age-related performance
decrements are a direct outgrowth of such per-
sonal factors as environmental background, ex-
perience, personality and motivation.

Notwithstanding the issues presented ,the liter-
ature clearly reveals that old age is generally

The assistance of Mary Anne Nelson, Alice Weikel,
Naney Jetton, John J. Mathews, Robert Tyson, and Jack
Dignum in the collection, processing, and/or analysis of
the data is gratefully acknowledged.

distinguished by: trends toward slowness in re-
action time; impaired psychomotor abilities;
restrictions in behavioral modification to environ-
mental conditions; deficiencies in the reception,
integration and use of new or novel information;
declines in perceptual and coding abilities; and
limitations in learning speed and capacity. How-
ever, numerous studies cited by Birren? and
Talland* illustrate that many such age-related
deficiencies are not uncommon among subjects
only 35-40 years old. This seems particularly
true in regard to specific types of speeded tasks
involving perceptual discrimination, mental ad-
dition or subtraction, handwriting speed, short-
term memory, abstract reasoning, word-synonym
responses, and information processing. Talland
emphasizes that “human capacity to transmit in-
formation, as tested by span of immediate recall,
diminishes with advancing age between the ages
of 20 and 70 years, more under some conditions
than under others.” * He further states that this
reduction in capacity, which is crucially related
to deficits in learning and memory, seems to
occur at a discontinuous rate, “particularly at
about 40 and again at about 60 years of age.”
The results obtained in a number of other
studies suggest that Talland’s theory might be
extended to include a variety of other abilities.
For example, progressively lower performance
means for groups over 35 years old have been
found in handwriting speed? and with a variety
of verbal as well as non-verbal intelligence
tests.°1° Friend and Zubek*! obtained similar re-
sults with wntimed tests of critical thinking, il-
lustrating that ability to weigh evidence and in-
terpret data generally tends to decline after age
35—irrespective of a time or speed factor. The
studies of Brown® and Szafran’ suggest that
certain psychomotor abilities are also apt to de-
cline at a relatively early age. Brown discovered



or interpretation of symbols, letters and degrees,
the subject’s tasks are to establish: true direc-
tional headings (Part I), the exact opposites of
true headings (Part IT), and the exact opposites
of true headings while the administrator pur-
posely attempts to disrupt performance by call-
ing aloud the words, “East,” “West,” “North,”
and “South” (Part III). In constructing the
test, Part I was deemed as a necessary “prelude”
to Part II but it was assumed that most of the
examinees would find it to be relatively easy and
that the performance scores, due to their narrow
range, would be of little or no use for purposes
of individual differentiation. As expected, the
performance scores for the 153 subjects were re-
stricted in range and were negligibly related to
age (ie. —.04). On the other hand, the correla-
tion of .27 between Part I and the A+L Grade
Average emerged as a pleasant surprise.

The variance represented in the distribution
of scores for Part II of the Directional Headings
Test was considerably greater than that obtained
for Part I. In general, most of the trainees
under 85 years of age performed rather well and
the lowest mean was for the group aged “35 to
39” rather than “40 & older.” Differences be-
tween the performance means of the group aged
“35 to 39” and two of the younger groups were
statistically significant. However, the pattern of
decline in the plotted means from the next-to-
the-youngest group was not followed by the old-
est group because three of the 17 trainees in the
latter attained moderately good scores, resulting
in a group mean above that characterizing the
performance of those aged 35-39.

Scores on Part IIT of the Directional Headings
Test were even more variable than the scores ob-
tained for Part II. This was presumably due to
the “conditions of distraction” under which the
third part was administered. Based on a review
of the answer sheets and comparisons of part
scores attained by each subject, it appeared that
some of the trainees of every age group became
quite confused and experienced great difficulty
in proceeding with the task—which was the same
as presented in the second part. However, most
of the examinees performed better on Part III
than on Part II. In fact, all of the group means
shown in Figure 18 are higher than those pre-
sented in Figure 17 for Part II. It should also
be noted that the plotted group means on Part
IIT reflect a consistent downward trend in per-

28

formance from the youngest group of trainees to
those of age “35 to 39.” If three of the 15 oldest.
students had not attained moderately good scores,
the downward trend would have been consistent
across all age groups. Contrary to expectations
however, no differences between the group means
were found to be statistically significant.

E. Locating Data Test. Figure 19 reveals a
progressive increase in the performance means
from the youngest group to those aged «30 to 34”
and then a rather sharp decline to the means of
the two oldest groups. The authors speculate
that the results relating to the Locating Data
Test may have been confounded by effects asso-
ciated with both chronological age and length of
experience in military ATC work. The youngest
trainees generally possessed less experience than
those 25 to 29 years old and this may have been
the reason why they experienced greater difficulty
with the test. For the same reason, those 25 to
29 may have found the test. more difficult than
did those of age 30 to 34. Beyond 34, however,
it is possible that the effects presumably asso-
ciated with experience were outweighted by ad-
verse effects associated with age. Although yet
unpublished, a current study involving job pro-
ficiency measures of 600 journeymen ATCSs at
17 high-density IFR airports has shown that
when the mean proficiency ratings are plotted
for groups having differential lengths of FAA
ATC service, there is an upward progression in
the plot from the lesser experienced groups to
the group haying 12-13 years of experience fol-
lowed by successively lower means for every
group thereafter. The results are highly similar
to those previously obtained in a corresponding
study® of over 600 journeymen engaged in Air
Route, or Center, control work. In both in-
stances, the results suggest that, although tenure
in FAA ATC work is an important asset, its
influence is eventually overcome by adverse ef-
fects associated with age; the most notable
changes occur at about 40 years of age. Thus,
a somewhat corollary theory would explain the
results obtained for the Locating Data Test with
trainees having different lengths of experience
in military control work.

F. ATP Problems and Following Oral Direc-
tions. Figure 20 presents data for CSC 540 Air
Traffic Problems (ATP). The plot closely re-
sembles that previously shown for the Locating
Data Test (see Figure 19) and, as before, the




. CSC 157 Part I (Exp. Adm.)

14 Abstract Reasoning

13

12 .

re -.24

iL .

10
Age Group 24 &< 25-29 30-34. 35-39 40 & >
N 45 123 45 39 39
Mean 14.3 12.2 13.3 ll. 9.4
$.D. 5.0 4.8 45 4.8 41

Ficure 22. Mean CSC 157 Abstract Reasoning Scores by Age Group for 291 ATC Trainees
Who Were Administered the Test Experimentally.

(Note: The mean score of the oldest group is significantly lower than the means of all
younger groups except those aged 35-39. Other significant differences involve the youngest
group versus groups 25-29 and 85-39, and the group 30-34 versus 35-39.)

CsC 157 Part II (Exp. Adm.)
Letter Sequence
15

14 TM

13 N\
re -.15 .

12 —..

u
Age Group 24& < — 25"29 30-34 35-39 40 & >
N 34 101 36 33 33
Mean 14.2 13.6 13.2 12.2 11.9
8.D. 4.4 4.3 4.7 4.9 4.7

Frevure 28, Mean CSC 157 Letter Sequence Scores by Age Group for 237 ATC Trainees Who
Took the Test on an Experimental Basis at Time of Entry Into ATC Training.

(Note: The only statistically significant difference is between the performance means of
the youngest and oldest groups.)

381



Scores of Scores of Scores of
189 & < 190-209 210 & >

Enroute Sample

40 & > 45.8 24
35-39 31.8 22
30-34 62.9 35
29&< 59.4 138
Total 55.7 219
Terminal Sample
<<
40 & > OI QQAX2 RANE
35-39 BEN 45.5 1
30-34 78.6 4
A
29&< 26 NN 53.9 52
Total 24,4 53.7 82
Enroutes_and Terminals Combined
40& > 37.9 29
35°39 36.4 33
30-34 67.4 49
29&< 57.9 190
Total 55.1 301

Ficure 4. Distribution of Composite CSC-ATC-Aptitude Test Scores by Age Group for 219 Enroute and 82 Terminal
ATC Trainees Who Were Officially Administered the CSC Test Battery But Were Selected at a Level Higher
Than GS-7 on the Basis of Exceptional Types and Amounts of Pre-FAA ATC-related Experience.

i



Enroute or Terminal
Students Who Failed

Ss in Lower Half of
Ny Distribution of Grades

3s in Upper Half of
Distribution of Grades

Academy Basic Training of Pass Cases Only of Pass Cases Only
~Ase Group a
Academic Grade Average
40&> 41.7 12
35-39 30.4. 30.4 23
30-34 31.0 29
29W&< 78.3 23
Total 44.8 87
Laboratory Grade Average
40&> 8.3 33.3 12
35-39 40.9 31.8 27.3 22
30-34 6 58 26: 34.5 29
Wb< 1,8 68.2 22
Total 14.1) PEN 41.2 85
Overall Academic + Laboratory Grade Average
40&> 8.3 Q. 41.7 12
35-39 39.1 39.0 21.7 23
30-34 55. 37.9 29
2a9&< 21.47; 78.3 23
Total 8 G1 94, 44.8 87

Frevure 6. Percentages of ATC Trainees* By Age Group Who Failed Academy Training or Passed With Grades
Comprising Either the Approximate Lower Half or Approximate Upper Half of the Distributions of Academic,
Laboratory, or Combined Academic and Laboratory Grades of the Pass Cases Only.

* The 88 Ss were randomly selected from specific age groups to establish a relatively “normalized” sample.
(Note: One § died and laboratory grades were not available for two other Ss; see text.)

14