From: tai@ailab.ncsu.edu (Scott Tai)
Newsgroups: rec.org.mensa
Subject: (T/F) TAI'S INTELLIGENCE DEBATE: INTRODUCTION
Date: 13 Apr 92 16:18:56 GMT
Reply-To: tai@ailab.ncsu.edu (Scott Tai)
Organization: NCSU Artificial Intelligence Systems Laboratory

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INTELLIGENCE AND HEREDITY
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You want facts?  You've got 'em! :)

INTRODUCTION 
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	The word "intelligence" was derived from a translation of
Aristotle's term "dia-noesis" which he defined to be the abstract
qualities (sensation, perception, memory, imagination, reasoning)
involved in all intellectual processes.
	It was not until the turn of the last century that scientists
began to search for a more technical definition.  Sir Francis Galton
(who in his Hereditary Genius, 1869, noted that intelligence and
greatness run in families) was the first to attempt an intelligence
test based on scientific--as opposed to empirical--data.  His test,
based on the hypothesis that there is a high correlation between
sensory acuity and general intelligence, has since proven to be
inaccurate.  It did, however, inspire an international search for a
functional intelligence test.  Since a modern definition of
intelligence was yet to be made, scientists continued to rely on
intuition and common-sense judgments to verify the validity of their
intelligence tests.
	It was the pragmatic Frenchman, Alfred Binet (1857-1911), who
first devised a functional intelligence test.  Working with a large
number of Parisian school children, Binet developed a test that
successfully separated the mentally retarded from the normal students
at an early age.  His tests were based on a variety of factors
including verbal adroitness, ability to perceive analogies and
abstractions, a capacity for problem solving, mathematics,
classification, causal connections and distance perception.
	Since he worked with children, Binet was forced to devise some
way to compensate for the variation in test performances caused by age
differences.  And it was this adjustment of test results according to
age which led directly to the modern "Intelligence Quotient" (I.Q.)
which is simply the mental age (derived by test performance) divided by
the chronological age times 100.  Binet's test was soon widely accepted
since it accurately reinforced intuitive judgments about individual
intelligence (i.e., those judged to be of subnormal intelligence scored
poorly on the test, while those judged to be highly intelligent scored
exceptionally well).  So the test was accepted not on the basis of an
exact definition of "intelligence" but rather because it reflected
accurately the intuitive judgments about a person's intelligence.  It
is important, therefore, to realize that an intelligence quotient can
only be based on relative performance.  Unlike the more measurable
attribute of height--which can be determined forever by the immortal
inch--intelligence is measured by comparison.  The fact that it is
administered to large numbers of people gives it solidarity and
stability.
	It was not long after man first gave birth to the concept of
"intelligence" that he began to conjure about the respective roles of
heredity and environment in its formation.  Until the development of
I.Q. tests, scientists could only guess--but given a means to measure
intelligence, they could at last make more accurate estimates.  For
many years the accepted figure for heredity (in intelligence causality)
was 75 to 80 percent.  More recently, however, environmentalists have
argued that early training and quality of environment are the major
factors producing a high or low I.Q.
	The environmentalists had almost dominated the purlieus of
I.Q.  while the geneticists sought the quiet paths of the birds
and the bees and the Drosophilus fruit flies.  But one scientist made
certain observations in print (favoring heredity 80 percent to 20
percent) and discovered perhaps to his surprise that his statements
quickly fanned a flame of controversy.
	The scientist was Arthur Jensen, Professor of Educational
Psychology at the University of California (Berkeley).  Previously the
author of numerous articles on individual differences in human
learning, and cultural, developmental and genetic determinants of
intelligence and learning ability, Jensen was invited by the editors of
the Harvard Educational Review to write an article entitled "How Much
Can We Boost I.Q. and Scholastic Achievement?"  The article stated that
since intelligence is largely hereditary, the I.Q. cannot be boosted
substantially by compensatory education.  The essay evoked many
responses both indignant and laudatory.  Some labeled the article
irresponsible and racist.  Others claimed that the press had seized
upon the article, exaggerated a few of its points and played them up
out of context to bolster their political and social stance.
	The fields of academia were thus well plowed and sown with the
seeds which sprouted forth in the Atlantic Monthly.  Professor Richard
J. Herrnstein, then chairman of the psychology department at Harvard
University, wrote a scholarly article entitled "I.Q."  In it he
reviewed the history of I.Q. tests, summarized with scientific
detachment many of Professor Jensen's findings, and put forth the
hypothesis that social standing will be based to some extent on
inherited differences among people.  Although many scientists felt that
Herrnstein only summarized familiar conclusions and research that had
been done over a long period of time--he was roundly attacked by
environmentalists.
	The issue, oversimplified, is this:  To what extent does
heredity influence the intelligence of an individual?  To what extent
does environment affect I.Q.?  How valid are I.Q. tests in measuring
intelligence?
	The purpose of the series of articles which follow is not to
present an answer or even an opinion--but rather to present a sampling
of the most lucid, concise arguments, gathered from prominent
researchers and academicians involved in the dispute.
	Draw your own conclusions, keeping in mind a last word from
Thomas Jefferson, a man who knew how to engage in argument and to rise
above it:  "I tolerate with the utmost latitude the right of others to
differ with me in opinion without imputing them criminality."


--------- 
Scott Tai 
92 / 911 / 6077