December 07, 2005
Wanted: More Race Realism, Less Moralistic Fallacy
J. Philippe Rushton
J. Philippe Rushton:
I.Q.: Why Africa is Africa – and Haiti Haiti]
"naturalistic fallacy," identified by
David Hume (1711–1776), occurs when reasoning jumps
from statements about what is to prescription
about what ought to be.
An example of the naturalistic
fallacy: approving of all wars if scientific evidence
showed warfare was part of human nature.
The converse of the naturalistic
fallacy is the
"moralistic fallacy"- jumping from
prescriptions about what ought to be to
statements about what is.
An example of the moralistic
fallacy: claiming that, because warfare is wrong, it
cannot be part of human nature.
The term "moralistic fallacy"
was coined by Harvard University microbiologist
Bernard Davis after calls for ethical guidelines to
control the study of what could allegedly become
"dangerous knowledge"…such as the genetic basis
For well over a generation, the
study of the genetic and racial aspects of I.Q. has
given rise to the best examples we have of the
moralistic fallacy in action. Happily, under the sheer
weight of evidence, there are now signs this
anti-intellectual and unscientific prohibition is
breaking down, at least in the academic world.
Despite repeated claims to the
contrary, there has been
no narrowing of the 15- to 18-point average IQ
difference between Blacks and Whites (1.1 standard
deviations). The differences are as large today as when
first measured nearly 100 years ago. These differences,
and the associated gaps in living standards, education
levels etc., are rooted in factors that are largely
heritable, not cultural. IQ differences are attributable
more to differences in brain size than to racism,
stereotype threat, item selection on tests, and all
the other suggestions given by the commentators.
It is time to meet reality. It is
time to stop committing the "moralistic fallacy"
that good science must conform to approved outcomes.
In 1969, the Harvard Educational
Review published a lengthy article by Berkeley
Arthur Jensen "How
Much Can We Boost IQ and School Achievement?"
|IQ tests measure socially
relevant general ability;|
|individual differences in IQ
have a high heritability, at least for the White
populations of the United States and Europe;|
programs have proved generally ineffective in
raising the IQs or school achievement of individuals
|because social mobility is
linked to ability, social-class differences in IQ
probably have an appreciable genetic component; and
tentatively, but most controversially,|
|the mean Black-White group
difference in IQ probably has some genetic
An enormous commotion ensued.
Jensen's conclusions, the theoretical issues they
raised, and the public policy recommendations that many
saw as stemming directly from them, were dubbed "Jensenism,"
a term which entered the dictionary.
Since then, Jensen has quietly
continued to publish. Steadily, his views have gained
support amongst fellow social scientists.
The Bell Curve
Richard Herrnstein and
Charles Murray presented general readers an update
of the evidence for the hereditarian position, along
with several policy recommendations. They introduced to
the general public the results of the 12-year National
Longitudinal Survey of Youth. This had found that most
17-year-olds with high scores on the
Armed Forces Qualification Test, regardless of
ethnic background, went on to occupational success by
their late 20s and early 30s. Those with low scores were
more inclined to welfare dependency.
The study also found that the
average IQ for African Americans was lower than those
for Latino, White, East Asian, and Jewish Americans (85,
89, 103, 106, and 113, respectively).
Currently, the existence of the
15-to-18 point difference (1.1 standard deviations)
between Blacks and Whites in the U.S. is not in itself a
matter of empirical dispute. A
meta-analytic review in Personnel Psychology
in 2001 by
Philip Roth and colleagues showed it also holds for
college and university application tests, for tests for
job applicants in corporate settings, and in the
Further, the Black-White IQ
difference shows up before 3 years of age on most
standardized test batteries, even after matching on
maternal education and other variables. Therefore it is
not due to poor education since this has not yet begun
to exert an effect. (The East Asian IQ advantage appears
by five years of age.)
The question still remaining: is
the cause of the group differences in average IQ purely
social, economic, and cultural? Or are genetic factors
To attempt a definitive answer, I
teamed up with Arthur Jensen and together we examined
ten categories of scientific evidence from around the
world published since Jensen’s path-breaking 1969 paper.
We concluded that the genetic
component in Black-White differences is even higher than
we had initially thought—likely 80%. This conforms to
the "default hypothesis" laid out in Jensen’s
The g Factor—that, by adulthood, genetic and
cultural factors carry the exact same weight in causing
the mean Black-White IQ difference as they do in causing
differences between individuals in IQ—about 80%
For each set of data we contrasted
a hereditarian model (50% genetic/50% cultural) and a
culture-only model (0% genetic/100% cultural). Our 50/50
model did not exclude environmental factors, but it did
require they be concretely demonstrable. Although the
evidence we reviewed provided strong support for the
genetic component of the model, we were unable to
demonstrate any environmental element.
Our 60-page review,
Thirty Years of Research on Race Differences in
Cognitive Ability, was published as the lead
article in the
June 2005 issue of Psychology, Public Policy, and Law,
a journal of the American Psychological Association,
along with four responses—three critical—and our own
reply (which lays out our refutations of our critics in
Here is some of the technical
evidence we reviewed that led us to our conclusions:
1. The Worldwide Pattern of IQ Scores.
Around the world, the average IQ
for East Asians centers around 106; for Whites, about
100; and for Blacks about 85 (in the United States) and
only 70 in sub-Saharan Africa. The same rank-order of
race differences is found for
"culture-fair" tests and reaction time measures.
(Reaction time tasks are so easy that all children can
do them in less than one second. More intelligent
children, measured by conventional IQ tests, perform
faster on these tasks. East Asians average faster
reaction times than Whites who have faster reaction
times than Blacks.)
VDARE.com readers may recall I
even traveled to South Africa to collect new IQ data
to corroborate the remarkably low test scores reported
for the general African population—mean IQ of 70. I
tested IQ scores from highly-selected Black students at
University of the Witwatersrand in Johannesburg.
Seven studies conducted at
universities in South Africa,
including my own, yielded a median IQ of 84.
Assuming that African university students are 1 standard
deviation (15 IQ points) above the population mean, as
university students typically are, the finding of a
median IQ of 84 corroborates the general population mean
All over the world, mean IQs differ
much less within major population groups than between
them. Whites have IQs close to 100 whether they live in
Europe, Canada, Australia,
New Zealand, or South Africa, whereas Blacks in
sub-Saharan Africa have IQs closer to 70 regardless of
whether they live in East, West, Central, or Southern
Africa—or whether the data were collected in the 1920s
or the 2000s
This worldwide pattern
contradicts the hypothesis that the low IQ of American
Blacks is due to
"White racism." Many of the African countries
showing a mean IQ = 70, such as Nigeria and Ghana, have
been independent for half a century—and the Caribbean
two centuries. There has been no documented
cultural achievement, or in IQ scores.
2. Race Differences are Most Pronounced on the
More g-loaded components of tests.
Charles Spearman coined the term
g for the general factor of mental ability (or
"general intelligence"), which he postulated lay
behind the observed ability of some children to do
better than others in a wide range of seemingly
Some test items load more on the
g factor than do other, more culturally malleable,
items. A test’s g loading is the best predictor,
not just of school grades and workplace performance, but
also of all the other indicators and correlates of
intelligence—including biological variables such as
brain size, reaction times, and heritability estimates
as calculated from twin studies.
Race differences are repeatedly
found to be higher on more g-loaded tests. Because
Black-White IQ differences are more pronounced on high
g-loaded tests than on low g-loaded tests,
the difference is unlikely to be the result of any
idiosyncratic cultural peculiarities in this or that
test. It is more likely to be due to heritage.
There is in fact no good evidence
that g is affected by anything other than
biology. That would require not just evidence that
training produces higher scores, but also evidence of
the broad transfer of training effects to other highly
Test constructors could in principle reduce the
Black–White difference to zero (or even reverse it) by
including only non-g items (or those negatively
loaded on g).
However, they would then be left
with a test that had little or no predictive power.
3. Blacks and Whites Regress Toward Their
Predicted (and Different) Means.
Basic genetic theory predicts that
the IQ of offspring will
regress towards the mean IQ of the population group
from which the parents come. This has been amply
documented for a number of physical traits in humans and
in other species.
Regression to the mean is seen,
typically, when individuals with high IQ scores mate.
Their children tend to show lower scores than their
parents. The converse happens for low IQ parents; they
have children with somewhat higher IQs. This is because
the parents pass on some, but not all, of their
exceptional genes to their offspring. It is analogous to
rolling a pair of dice and having them come up two 6’s
or two 1’s. The odds are that on the next roll, you will
get some value that is not quite as high (or as low).
Genetic theory predicts the precise
magnitude of the regression effect. Culture-only theory
makes no systematic or quantitative predictions. Black
children with parents of IQ 115 regress to the Black IQ
average of 85, while White children with parents of IQ
115 regress to the White IQ average of 100. Regression
to a lower average IQ helps to explain the fact that
Black children born to high IQ, wealthy, Black parents
have test scores 2 to 4 points lower than do White
children born to low IQ, poor White parents.
note: This finding has important social and political
implications. It means the strategy of buying off the
black elite with
affirmative action preferences cannot be a stable
solution in the longer term, because the black elite's
children will not be
able to take advantage of their parents' success.]
4. The Gene-Environment Architecture of IQ is the
Same in all Races.
Studies of Black, White, and East
Asian twins show that the heritability of IQ is about
the same in all races (50% or higher). There has been no
indication of any special cultural influences—such as
extreme deprivation, or being raised as a visible
minority—being at work in one group and not in the
A strong genetic contribution is
also indicated by Black-White differences being most
pronounced on the more heritable components of tests.
One study even found that the
degree of inbreeding depression (the tendency for inbred
populations to suffer more intensely from various types
of defects) found in various subtests
conducted on the Japanese in Japan predicted the
degree of Black-White differences found in the same
subtests in the United States.
There is no known non-genetic
inbreeding depression effects, or for why Japanese
results can be used to predict Black-White differences
5. Brain Size Differences.
Larger brains are more intelligent
because they contain more neurons and synapses and can
process information more efficiently. Two dozen studies
using magnetic resonance imaging (MRI) have shown that
brain size is related to IQ differences within race with
a correlation of about 0.40.
The different races also have
different brain sizes.
One study followed
50,000 children from birth to age 7. The East Asian
American children in the sample averaged a larger head
circumference at birth, 4 months, 1 year, and 7 years
than did the White children, who in turn averaged a
larger head circumference than did the Black children.
By age 7, the
East Asian American children had an average IQ of
110; Whites, 102; and Blacks 90.
The findings on race differences in
brain size are
highly reliable. They have been confirmed using four
independent procedures—MRI, endocranial volume from
empty skulls, wet brain weight at autopsy, and external
head size measures.
How do our critics handle this
evidence? Rather than refuting or challenging these
facts, they completely ignore them.
6. Trans-Racial Adoption Studies.
Average race differences remain
despite adoption of blacks by White middle-class
parents. This has been demonstrated by a number of
surveys, notably the
Minnesota Transracial Adoption Study. The effects
are especially noticeable after puberty.
7. Racial Admixture Studies.
Dozens of studies have found that
lighter-skinned African Americans and the
mixed-race "Coloreds" of South Africa (also
lighter skinned) have average IQs between those of (for
the most part) unmixed groups of Blacks and Whites. The
mixed-race "Colored" population of South Africa
has an average IQ of 85, intermediate to the respective
African and White means of 70 and 100.
Research has shown that the finding
is not due to lighter-skinned Blacks being treated
better through "expectancy effects" or
"labeling theory." In the Minnesota Transracial
Adoption Study, for example, some children were
misclassified, with their adoptive parents wrongly
believing that the mixed-race children had two Black
biological parents. Yet these children had the same IQs
as those of other mixed-race children correctly believed
by their adoptive parents to have had one Black and one
White biological parent.
The IQ of Blacks in the United
States, around 85, is substantially higher than the IQs
of Blacks in sub-Saharan Africa. There are two
explanations for this. The first is that American Blacks
have about 25% White ancestry. According to genetic
theory this would raise their IQs above the level of
Blacks in Africa. The second is that American Blacks
enjoy much higher standards of living, nutrition,
health care than they have in societies run by
Living in a White society has
raised rather than lowered the IQs of American Blacks.
8. Race Differences are Seen Over a Wide Range of
East Asians and Blacks fall at the
two ends of a continuum. Whites are in the middle. In
addition to brain size and IQ, this shows up on a suite
of 60 other life-history variables. These include speed
of maturation and longevity, personality and
temperament, family stability and crime, and sexual
behavior and fertility.
One striking example: around the
world the rate of dizygotic (i.e. two-egg) twinning is
less than 4 per 1,000 births among East Asians, 8 among
Whites, and 16 or greater among Blacks. The tendency to
produce dizygotic twins is heritable and mediated by sex
Another example: Black babies sit,
crawl, walk, and put on their clothes earlier than
Whites or East Asians. For walking: East Asians, 13
months; Whites, 12 months; Blacks, 11 months.
Blacks also have an earlier age of
sexual maturity than do Whites, who in turn have an
earlier age than do East Asians, whether measured by age
of first menstruation, first sexual experience, or first
9. Race Differences and Human Origins Research.
The fact that the three-way pattern
in IQ, brain size, and other traits is not unique to the
United States but occurs internationally is consistent
with a single, genetic-evolutionary theory. The
currently most commonly accepted view of human origins,
"out-of-Africa" theory, posits that Homo
sapiens arose in Africa about 150,000 years ago and
then expanded northward beyond Africa about 100,000
years ago, with a European-East Asian split about 41,000
Evolutionary selection pressures
were different in the hot savanna, where Africans lived,
than in the cold northern regions Europeans experienced,
or the even colder Arctic regions of East Asians.
Thus, the further north the
ancestral human populations migrated out of Africa,
about 100,000 years ago, the more they encountered the
cognitively-demanding problems of gathering and
storing food, gaining shelter, making clothes, and
raising children successfully during prolonged winters.
As these populations evolved into
present‑day East Asians and Europeans, the ecological
pressures selected for larger brains, slower rates of
maturation, and lower levels of sex hormone, and all the
other life history characteristics.
10. Culture-Only Theory Hypotheses Fail to
Account for the Race-IQ differences.
Culture-only theories do not
explain the race differences in IQ. They have especially
failed in explaining the East Asian data. The concept
that Black-White IQ differences are due to differences
in socio-economic status does not survive close
examination. Adjusting for socioeconomic status only
reduces the Black-White IQ difference by about
one-third. Nor does the evidence support other
culture-only hypotheses such as
test bias, test anxiety, or the consequences of
being a minority in a White society.
Massive society-wide interventions
such as ending segregation, the subsequent nationwide
program of school busing to achieve racial balance, and
Head Start programs have
failed to reduce the differences. Head Start
programs did produce modest gains in school retention
and graduation rates among Whites—but not Blacks.
Large scale, often well-publicized,
countywide amelioration projects (such as the $2 billion
program in affluent Montgomery County, Maryland, as well
Kansas City, Missouri, school district,
under judicial supervision since 1985), have never
yet made a replicable dent in the Black-White
achievement gap (despite low
student-teacher ratios and computers in every
The narrowing of the gap between
Black-White social conditions has not led to any change
in the magnitude of the Black-White IQ difference in
over 100 years.
How do critics explain the fact
that the Black-White difference is greater on backward
than on forward digit span memory, or on the more
complex rather than simple reaction time
measures—exactly as predicted by Spearman’s (1927)
How do they explain the fact that
Black students from families with incomes of $80,000 to
$100,000 score considerably lower on the SAT than White
students from families with $20,000 to $30,000 incomes?
How do they explain why social
class factors, all taken together, only cut the
Black-White achievement gap by a third?
Culture-only theory cannot predict
these facts; often its predictions are opposite to the
Discussing this evidence with those
who, for whatever reason, refuse to consider the
behavioral genetic or evolutionary aspect of race and
intelligence is little more than arguing past one
But the harsh fact is that the more
we remove environmental disadvantages, improving
everybody’s intellectual performance, the greater will
be the relative influence of genetic factors.
Equal opportunity will result in
unequal outcomes—within families, between
families, and between population groups.
Perhaps the fact that we have
learned to live with the first, and to a lesser degree
the second, offers some hope we can learn to do so for
J. Philippe Rushton [email
him] is a professor of psychology at the University of
Western Ontario, the author of
Race, Evolution, and Behavior: A Life History