From: scott@ailab.ncsu.edu (Scott A Tai)
Subject: Do IQ Tests Measure Intelligence?
Reply-To: tai@m-net.ann-arbor.mi.us
Organization: NCSU Artificial Intelligence Systems Laboratory
Date: Thu, 30 Jul 1992 03:07:26 GMT


DAVID C. McCLELLAND 
DO I.Q. TESTS MEASURE INTELLIGENCE?
-----------------------------------

	Psychology has one great practical success to its credit in the
twentieth century--namely the intelligence testing movement.  Many
tests have been devised which predict success in school with remarkable
regularity.  Literally tens of thousands of validity coefficients have
been calculated, demonstrating that those who score higher on aptitude
or intelligence tests usually do better in their school work.
Selecting, at random, a finding which is quite typical for the United
States, I recently observed in a longitudinal study reported by Costa
that Kuhlman-Anderson I.Q. scores obtained in the sixth grade
correlated 0.59 with twelfth-grade rank in class.  In other words
knowing how a child scores on an intelligence test when he is eleven or
twelve years old enables you to predict fairly accurately how well he
or she will be doing in school some six or seven years later.  Rank in
class at graduation from secondary school in turn predicts whether he
can go on to the university and how good a university he or she will
get into.  As a consequence, knowing a person's intelligence-test score
or scholastic-aptitude-test score has become a matter of great
importance in the United States, not only to admissions officers who
use it to pick people for college but also to businesses and civil
service commissions who use it to decide who is "bright enough" to be a
police officer, a social worker, or a firefighter.
	Testing has therefore become big business.  The Educational
Testing Service which gives the Scholastic Aptitude Test used by most
of the better-known colleges and universities in the United States
employs several thousand people and has a large plant spread over
hundreds of acres in Princeton, New Jersey.  Thousands of young people
pay to take its tests annually to see if they are qualified to get into
the college of their choice.  The testing technology has been so sold
to the American public that only in a few of the more "backward" parts
of the society is it not used in the schools or business or civil
service.  And of course it is spreading fast to the rest of the world,
which is beginning to discover the utility of tests for picking those
who will do well in school.
	To be sure, the testers themselves loudly insist that there are
other important human qualities besides the ability to take scholastic
aptitude tests, but as Wing and Wallach have shown, admissions officers
may believe they take these other qualities into account but in fact
their selection decisions can be almost perfectly predicted by
aptitude-test scores alone.  The desire to select more "intelligent"
people for schooling or for almost any occupation proves overpowering.
It quickly reduces other qualifications to insignificance.
	While the intelligence-testing movement in the United States
has been moving on from one triumph to the next, some questions have
been raised about its theoretical underpinnings, both by scholars and
by policy makers who wonder if its growing power over people's lives is
justified.  One difficulty with tests has long been known but little
commented on perhaps because its seriousness has not been fully
appreciated.  It is very simply that if academic achievement tests are
taken seriously as measures of real competence, then the *quality* of
education does not seem to contribute to improving competence.  Back in
the 1930's in the United States, a number of private schools tried to
improve the quality of their education as part of what was then known
as the "progressive education movement".  Standardized scholastic
achievement tests were used to evaluate the effects of this supposedly
improved education as compared with more traditional teaching.
	By and large no effects of the supposedly higher-quality
education could be discovered in the test scores.  The educators felt
they were doing a better job but the test scores did not indicate that
they were.  The same finding has turned up again and again since that
time.  Certain colleges in the United States are widely acknowledged to
be better than other colleges--in the sense that they have better
faculties, more books in the library, higher endowments, better
laboratory facilities, and so forth.  Yet repeated studies as
summarized by Jacob have failed to show any test-score differences
attributable to the better education supposedly obtained in the elite
colleges.  If the graduates of those colleges perform better on
achievement tests, it is because they scored higher on them at entrance
to college, not because they received a better education subsequently.
	Most recently in a very important social document on equality
of educational opportunity, Coleman again showed that the *quality* of
education (here in secondary school) seemed to have very little effect
on the academic achievement test scores of children.  In other words
the children who went to poor schools with poorly trained teachers,
dilapidated buildings, and crowded classrooms did no worse on the tests
than children who went to excellent, well-equipped schools with low
teacher-pupil ratios, once one had corrected for the initial
differences in intelligence and social background of the pupils
attending the two types of schools.  In other words what the test
results seem to have shown over and over again is that quality of
education makes no difference in improving competence.
	What does make a difference are the attributes of the people
getting the education--their intelligence, their social
characteristics, and so forth.  Why then should citizens spend so much
money trying to improve education?  Why should educational
psychologists be trying to find better ways of educating pupils?  Why
is money wasted on conferences to try to find ways of improving
education--if in fact the data clearly show that educational variations
have very little effect on academic achievement, which in turn is
considered the main measure of competence for life's tasks?
	One reason is that we keep suspecting that the educators may be
right in continuing to think that the quality of education does make a
difference.  It may be the psychological testers who are wrong:  their
tests may simply not be adequate measures of the competence which
better education produces.  In fact there may even be a built-in
theoretical reason why most existing tests are inadequate measures of
the variations in the quality of education.  Most testers have worked
hard to create tests which are reliable--that is, which will give the
same score when the same individual is tested again.  An instrument
which is designed to be very reliable may not be very sensitive to
changes that have actually taken place in the person through
education.
	But this theoretical problem has never shaken the
self-confidence of the testing movement.  It has continued to roll on
like a juggernaut overwhelming all such doubts.
	When many psychologists began to examine really seriously for
the first time the assumptions on which the intelligence testing
movement had been built, it took them no time at all to discover that
many intelligence tests had a built-in middle-class bias.  The
vocabulary used in the tests was so-called "standard English", not the
dialect spoken in many ghetto communities.  So the children from these
communities often did not even understand the instructions for the
tests, let alone the words they were supposed to identify which were
not part of the vocabulary in common use in their community.  Correct
answers to questions also often assume a standard middle-class way of
life.  For example a child is asked on an intelligence test, "What
would you do if you were sent to the store by your mother to buy
something and you found the store didn't have it?"  The "intelligent"
or correct answer is supposed to be that you would go to another store
to see if they had it.  However this is certainly not an intelligent
answer for a ghetto child who is under strict orders from his mother to
come straight home from the store because she is afraid the child might
be robbed or beaten if he or she strayed too far from familiar
territory.  Yet if he says he would go home he is judged by the testers
to be less intelligent.  It is also easy to see from these examples why
there is a correlation between test performance and later performance
in school because the teacher, as a representative of standard
middle-class culture, will expect the same language and types of
behavior as the person who made up the so-called intelligence test.
The teacher will either not understand the dialect that is used in
class or will give the child a lower mark for using "bad" language and
the ghetto child will before long go through life stigmatized as being
less intelligent and a poor student.
	Looking at the problem this way forced psychologists to
consider seriously another possible explanation for many of the
existing correlations between intelligence test scores, doing well in
school, and holding down higher-status jobs later in life.  Those who
control not only economic and social opportunities but also what
language and values are the standards by which others will be judged,
may in fact be able to use test scores to maintain their power.  All
one needs to assume is that more powerful families are in a much better
position to help their children get higher-status jobs: they know the
right people; they can send their children to the right schools; they
can use their influence to get them jobs directly.
 So it turns out that people in higher-status jobs score higher on
so-called intelligence tests.
	But where is the direct evidence that the higher score on the
test in fact indicated that the person was better able to do the
higher-status job?  As every psychologist knows, correlation does not
mean causation.  It doesn't follow that because professionals score
higher than laborers on certain tests that it is the ability to perform
those particular tests which enabled them to be professionals rather
than laborers.  The reason why people have assumed that causation was
involved is that the test scores were supposed to indicate how
intelligent the person was, and it seems reasonable to assume that
being a professional requires more of something called intelligence
than being a laborer does.  However it is by no means as self-evident
as it once was that these test scores measure the kind of intelligence
implied by the logic of this argument.  They may simply indicate that
the person has the *credentials* that the power elite insists that he
or she must have in order to hold a higher-status job.  The connection
between test performance and job performance may well be extrinsic
rather than intrinsic.  That is, being able to use the right words may
have nothing to do intrinsically with whether a person is a cleverer
lawyer, but those in power in a society simply decree that a person
cannot be a lawyer unless he or she uses the correct vocabulary.  In
this sense the test becomes an instrument for those in power to screen
out those who do not know the right words and who are therefore
"unqualified" to be lawyers in the minds of those who control such
things.  Now such a selection procedure may be justifiable in one way
or another but it does serve to make clear that the central issue is
who is in power and controlling resources, not who is genetically
inferior in intelligence.
	American psychologists have long accepted without question
Professor Terman's conclusion that his gifted children (those with
higher intelligence test scores) grew up to be more successful
occupationally, maritally, and socially than those of average
intelligence and that they showed fewer "morally deviant" forms of
psychopathology such as alcoholism or homosexuality.  Yet the power
analysis just carried out suggests that neither Professor Terman nor
anyone else has as yet brought forward conclusive evidence that it is
giftedness per se as he measured it that is responsible for these
happier life outcomes.
 For his gifted children were also drawn very disproportionally from
the ranks of the educated, the wealthy, and the powerful.  This means
that they had not only a better chance to acquire the characteristics
measured in the test but also had to be happier (since they had more
money) and also to have access to higher occupations and better social
standing.  Maybe test scores measuring "giftedness" are simply another
symptom of their generally more favorable social status.


-- Scott Tai
   tai@m-net.ann-arbor.mi.us
   198 / 2060 / 12677
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