Race and crime: an international dilemma.
Rushton, J. Philippe
Society, Jan-Feb 1995
In their magisterial Crime and Human Nature, J.Q. Wilson and R.J. Herrnstein
noted that the Asian underrepresentation in U.S. crime statistics posed
a theoretical problem. The solution proposed by criminologists as early
as the 1920s was that the Asian "ghetto" protected members from
the disruptive tendencies of the outside society. For blacks, however,
the ghetto is said to foster crime.
The overrepresentation of blacks in U.S. crime statistics has existed
since the turn of the twentieth century. The census of 1910 showed more
blacks than whites in jail, in the north as well as in the south. Official
figures from the 1930s through the 1950s showed that the number of blacks
arrested for crimes of violence in proportion to the number of whites ranged
from 6:1 to 16:1. These statistics have not improved in the interim.
Breaching a long taboo, liberals from Bill Clinton to Jesse Jackson
have recently made it respectable to theorize about "black-on-black"
crime. Conservative magazines like the National Review have also begun
to discuss aspects of the race/crime link (see "Blacks... and Crime,"
May 16, 1994; "How to Cut Crime," May 30, 1994). What is yet
to be acknowledged, however, is the international generalizability of the
race/crime relationship. The matrix found within the United States, with
Asians being most law-abiding, Africans least, and Europeans intermediate,
is to be observed in other multiracial countries like Britain, Brazil,
and Canada. Moreover, the pattern is revealed in China and the Pacific
Rim, Europe and the Middle East, and Africa and the Caribbean. Because
the "American dilemma" is global in manifestation, explanations
must go well beyond U.S. particulars.
I emphasize at the outset that enormous variability exists within each
of the populations on many of the traits to be discussed. Because distributions
substantially overlap, with average differences amounting to between 4
and 34 percent, it is highly problematic to generalize from a group average
to a particvular individual. Nonetheless, as I hope to show, significant
racial variation exists, not only in crime but also in other traits that
predispose to crime, including testosterone, brain size, temperament, and
The global nature of the racial pattern in crime is shown in data collated
from INTERPOL using the 1984 and 1986 yearbooks. After analyzing information
on nearly 100 countries, I reported, in the 1990 issue of the Canadian
Journal of Criminology, that African and Caribbean countries had double
the rate of violent crime (an aggregate of murder, rape, and serious assault)
than did European countries, and three times more than did countries in
the Pacific Rim. Averaging over the three crimes and two time periods,
the figures per 100,000 population were, respectively, 142, 74, and 43.
I have corroborated these results using the most recent INTERPOL yearbook
(1990). The rates of murder, rape, and serious assault per 100,000 population
reported for 23 predominantly African countries, 41 Caucasian countries,
and 12 Asian countries were: for murder, 13, 5, and 3; for rape, 17, 6,
and 3; and for serious assault, 213, 63, and 27. Summing the crimes gave
figures per 100,000, respectively, of 243, 74, and 33. The gradient remained
robust over contrasts of racially homogeneous countries in northeast Asia,
central Europe, and sub-Saharan Africa, or of racially mixed but predominantly
black or white/Amerindian countries in the Caribbean and Central America.
In short, a stubborn pattern exists worldwide that requires explanation.
Testosterone and the Family
The breakdown of the black family and the strengths of the Asian family
are often used to explain the crime pattern within the United States. Learning
to follow rules is thought to depend on family socialization. Since the
1965 Moynihan Report documented the high rates of marital dissolution,
frequent heading of families by women, and numerous illegitimate births,
the figures cited as evidence for the instability of the black family in
America have tripled.
A similarly constituted matrifocal black family exists in the Caribbean
with father-absent households, lack of paternal certainty, and separate
bookkeeping by spouses. The Caribbean pattern, like the American one, is
typically attributed to the long legacy of slavery. However, the slavery
hypothesis does not fit data from sub-Saharan Africa. After reviewing long-standing
African marriage systems in the 1989 issue of Ethology and Sociobiology,
anthropologist Patricia Draper of Pennsylvania State University concluded:
"coupled with low investment parenting is a mating pattern that permits
early sexual activity, loose economic and emotional ties between spouses...
and in many cases the expectation on the part of both spouses that the
marriage will end in divorce or separation, followed by the formation of
The African marriage system may partly depend on traits of temperament.
Biological variables such as the sex hormone testosterone are implicated
in the tendency toward multiple relationships as well as the tendency to
commit crime. One study, published in the 1993 issue of Criminology by
Alan Booth and D. Wayne Osgood, showed clear evidence of a testosterone-crime
link based on an analysis of 4,462 U.S. military personnel. Other studies
have linked testosterone to an aggressive and impulsive personality, to
a lack of empathy, and to sexual behavior. Testosterone levels explain
why young men are disproportionately represented in crime statistics relative
to young women, and why younger people are more trouble-prone than older
people. Testosterone reliably differentiates the sexes and is known to
decline with age.
Ethnic differences exist in average level of testosterone. Studies show
3 to 19 percent more testosterone in black college students and military
veterans than in their white counterparts. Studies among the Japanese show
a correspondingly lower amount of testosterone than among white Americans.
Medical research has focused on cancer of the prostate, one determinant
of which is testosterone. Black men have higher rates of prostate cancer
than do white men who in turn have higher rates than do Oriental men.
Sex hormones also influence reproductive physiology. Whereas the average
woman produces 1 egg every 28 days in the middle of the menstrual cycle,
some women have shorter cycles and others produce more than one egg; both
events translate into greater fecundity including the birth of dizygotic
(two-egg) twins. Black women average shorter menstrual cycles than white
women and produce a greater frequency of dizygotic twins. The rate per
1,000 births is less than 4 among east Asians, 8 among whites, and 16 or
greater among Africans and African-Americans.
Racial differences exist in sexual behavior, as documented by numerous
surveys including those carried out by the World Health Organization. Africans,
African-Americans and blacks living in Britain are more sexually active,
at an earlier age, and with more sexual partners than are Europeans and
white Americans, who in turn are more sexually active, at an earlier age,
and with more sexual partners than are Asians, Asian-Americans, and Asians
living in Britain. Differences in sexual activity translate into consequences.
Teenage fertility rates around the world show the racial gradient, as does
the pattern of sexually transmitted diseases. World Health Organization
Technical Reports and other studies examining the worldwide prevalence
of AIDS, syphilis, gonorrhea, herpes, and chlamydia typically find low
levels in China and Japan and high levels in Africa, with European countries
intermediate. This is also the pattern found within the United States.
International data on personality and temperament show that blacks are
less restrained and less quiescent than whites and whites are less restrained
and less quiescent than Orientals. With infants and young children observer
ratings are the main method employed, whereas with adults the use of standardized
tests are more frequent. One study in French-language Quebec examined 825
four- to six-year olds from 66 countries rated by 50 teachers. All the
children were in preschool French-language immersion classes for immigrant
children. Teachers consistently reported better social adjustment and less
hostility-aggression from east Asian than from white than from African-Caribbean
children. Another study based on twenty-five countries from around the
world showed that east Asians were less extraverted and more anxiety-prone
than Europeans who in turn were less outgoing and more restrained than
Differences between individuals in testosterone and its various metabolites
are about 50 percent heritable. More surprising to many are the studies
suggesting that criminal tendencies are also heritable. According to American,
Danish, and Swedish adoption studies, children who were adopted in infancy
were at greater risk for criminal convictions if their biological parents
had been convicted than if the adopting parents who raised them had been
convicted. In one study of all 14,427 nonfamilial adoptions in Denmark
from 1924 to 1947, it was found that siblings and half-siblings adopted
separately into different homes were concordant for convictions.
Convergent with this adoption work, twin studies find that identical
twins are roughly twice as much alike in their criminal behavior as fraternal
twins. In 1986 I reported the results of a study of 576 pairs of adult
twins on dispositions to altruism, empathy, nurturance, and aggressiveness,
traits which parents are expected to socialize heavily. Yet 50 percent
of the variance in both men and women was attributable to genetics. The
well-known Minnesota Study of Twins Raised Apart led by Thomas J. Bouchard,
Jr., has confirmed the importance of genetic factors to personality traits
such as aggressiveness, dominance, and impulsivity. David Rowe at the University
of Arizona reviewed much of this literature in his 1994 book Limits of
Family Influence. He explains how siblings raised together in the same
family may differ genetically from each other in delinquency.
Genes code for enzymes, which, under the influence of the environment,
lay down tracts in the brains and neurohormonal systems of individuals,
thus affecting people's minds and the choices they make about behavioral
alternatives. In regard to aggression, for example, people inherit nervous
systems that dispose them to anger, irritability, impulsivity, and a lack
of conditionability. In general, these factors influence self-control,
a psychological variable figuring prominently in theories of criminal behavior.
Behavior genetic studies provide information about environmental effects.
As described in Rowe's book, the important variables turn out to be within
a family, not between families. Factors such as social class, family religion,
parental values, and child-rearing styles are not found to have a strong
common effect on siblings. Because individual minds channel common environments
in separate ways siblings acquire alternative sets of information. Although
siblings resemble each other in their exposure to violent television programs,
it is the more aggressive one who identifies with aggressive characters
and who views aggressive consequences as positive.
Within-family studies show that intelligence and temperament separate
siblings in proneness to delinquency. It is not difficult to imagine how
an intellectually less able and temperamentally more impulsive sibling
seeks out a social environment different from his or her more able and
less impulsive sibling. Within the constraints allowed by the total spectrum
of cultural alternatives, people create environments maximally compatible
with their genotypes. Genetic similarity explains the tendency for trouble-prone
personalities to seek each other out for friendship and marriage.
One objection sometimes made to genetic theories of crime is the finding
that crime rates fluctuate with social conditions. Generational changes
in crime, however, are expected by genetic theories. As environments become
less impeding and more equal, the genetic contribution to individual difference
variation necessarily becomes larger. Over the last 50 years, for example,
there has been an increase in the genetic contribution to both academic
attainment and longevity as harmful environmental effects have been mitigated
and more equal opportunities created. Thus, easing social constraints on
underlying "at risk" genotypes leads to an increase in criminal
The role of low cognitive ability in disposing a child to delinquency
is established even within the same family where a less able sibling is
observed to engage in more deviant behavior than an advantaged sibling.
Problem behaviors begin early in life and manifest themselves as an unwillingness
or inability to follow family rules. Later, drug abuse, early onset of
sexual activity, and more clearly defined illegal acts make up the broad-based
syndrome predicted by low intelligence.
Racial differences exist in average IQ-test scores and again the pattern
extends well beyond the United States. The global literature on IQ was
reviewed by Richard Lynn in the 1991 issue of Mankind Quarterly. Caucasoids
of North America, Europe, and Australasia generally obtained mean IQs of
around 100. Mongoloids from both North America and the Pacific Rim obtained
slightly higher means, in the range of 101 to 111. Africans from south
of the Sahara, African-Americans, and African-Caribbeans (including those
living in Britain) obtained mean IQs ranging from 70 to 90.
The question remains of whether test scores are valid measures of group
differences in mental ability. Basically, the answer hinges on whether
the tests are culture-bound. Doubts linger in many quarters, although a
large body of technical work has disposed of this problem among those with
psychometric expertise, as shown in the book of surveys by Snyderman and
Rothman. This is because the tests show similar patterns of internal item
consistency and predictive validity for all groups, and the same differences
are to be found on relatively culture-free tests.
Novel data about speed of decision making show that the racial differences
in mental ability are pervasive. Cross-cultural investigations of reaction
times have been done on nine- to twelve-year olds from six countries. In
these elementary tasks, children must decide which of several lights is
on, or stands out from others, and move a hand to press a button. All children
can perform the tasks in less than one second, but more intelligent children,
as measured by traditional IQ tests, perform the task faster than do less
intelligent children. Richard Lynn found Oriental children from Hong Kong
and Japan to be faster in decision time than white children from Britain
and Ireland who were faster than black children from Africa. Arthur Jensen
has reported the same three-way pattern in California.
The relation between mental ability and brain size has been established
in studies using magnetic resonance imaging, which, in vivo, construct
three-dimensional pictures of the brain and confirm correlations reported
since the turn of the century measuring head perimeter. The brain size/cognitive
ability correlations range from about 0.10 to 0.40. Moreover, racial differences
are found in brain size. It has often been held that racial differences
in brain size, established in the nineteenth century, disappear when corrections
are made for body size and other variables such as bias. However, modern
studies confirm nineteenth-century findings.
Three main procedures have been used to estimate brain size: (a) weighing
wet brains at autopsy; (b) measuring the volume of empty skulls using filler;
and (c) measuring external head size and estimating volume. Data from all
three sources triangulate on the conclusion that, after statistical corrections
are made for body size, east Asians average about 17 c[m.sup.3] (1 cubic
inch) more cranial capacity than whites who average about 80 c[m.sup.3]
(5 cubic inches) more than blacks. Ho and colleagues at the Medical College
of Wisconsin analyzed brain autopsy data on 1,261 American subjects aged
25 to 80 after excluding obviously damaged brains and reported, in the
1980 issue of Archives of Pathology and Laboratory Medicine, that, after
controlling for age and body size, white men averaged 100 grams more brain
weight than black men, and white women averaged 100 grams more brain weight
than black women. With endocranial volume, Beals and colleagues computerized
the world database of up to 20,000 crania and published their results in
the 1984 issue of Current Anthropology. Sex-combined brain cases differed
by continental area with populations from Asia averaging 1,415 c[m.sup.3],
those from Europe averaging 1,362 c[m.sup.3], and those from Africa averaging
Using external head measurements I have found, after corrections are
made for body size, that east Asians consistently average a larger brain
than do Caucasians or Africans. Three of these studies were published in
the journal Intelligence. In a 1991 study, from data compiled by the U.S.
space agency NASA, military samples from Asia averaged 14 c[m.sup.3] more
cranial capacity than those from Europe. In a stratified random sample
of 6,325 U.S. Army personnel measured in 1988 for fitting helmets, I found
that Asian-Americans averaged 36 c[m.sup.3] more than European-Americans
who averaged 21 c[m.sup.3] more than African-Americans. Most recently,
I analyzed data from tens of thousands of men and women aged 25 to 45 collated
by the International Labour Office in Geneva and found that Asians averaged
10 c[m.sup.3] more than Europeans and 66 c[m.sup.3] more than Africans.
Racial differences in brain size and IQ show up early in life. Data
from the National Collaborative Perinatal Project on 19,000 black children
and 17,000 white children show that black children have a smaller head
perimeter at birth and, although they are born shorter in stature and lighter
in weight, by age seven "catch-up growth" leads them to be larger
in body size than white children, but still smaller in head perimeter.
Head perimeter at birth correlated with IQ at age seven in both the black
and the white children.
Origins of Race Differences
Racial differences exist at a more profound level than is normally considered.
Why do Europeans average so consistently between Africans and Asians in
crime, family system, sexual behavior, testosterone level, intelligence,
and brain size? It is almost certain that genetics and evolution have a
role to play. Transracial adoption studies indicate genetic influence.
Studies of Korean and Vietnamese children adopted into white American and
white Belgian homes showed that, although as babies many had been hospitalized
for malnutrition, they grew to excel in academic ability with IQs ten points
higher than their adoptive national norms. By contrast, Sandra Scarr and
her colleagues at Minnesota found that at age 17, black and mixed-race
children adopted into white middle-class families performed at a lower
level than the white siblings with whom they were raised. Adopted white
children had an average IQ of 106, an average aptitude based on national
norms at the 59th percentile, and a class rank at the 54th percentile;
mixed-race children had an average IQ of 99, an aptitude at the 53rd percentile,
and a class rank at the 40th percentile; and black children had an average
IQ of 89, an aptitude at the 42nd percentile, and a class rank at the 36th
No known environmental variable can explain the inverse relation across
the three races between gamete production (two-egg twinning) and brain
size. The only known explanation for this trade-off is life-history theory.
A life-history is a genetically organized suite of characters that evolved
in a coordinated manner so as to allocate energy to survival, growth, and
reproduction. There is, in short, a trade-off between parental effort,
including paternal investment, and mating effort, a distinction Patricia
Draper referred to as one between "cads" and "dads."
Evolutionary hypotheses have been made for why Asians have the largest
brains and the most parenting investment strategy. The currently accepted
view of human origins, the "African Eve" theory, posits a beginning
in Africa some 200,000 years ago, an exodus through the Middle East with
an African/non-African split about 110,000 years ago, and a Caucasoid/Mongoloid
split about 40,000 years ago. Evolutionary selection pressures are different
in the hot savanna where Africans evolved than in the cold arctic where
The evidence shows that the further north the populations migrated out
of Africa, the more they encountered the cognitively demanding problems
of gathering and storing food, gaining shelter, making clothes, and raising
children successfully during prolonged winters. The evolutionary sequence
fits with and helps to explain how and why the variables cluster. As the
original African populations evolved into Caucasoids and Mongoloids, they
did so in the direction of larger brains and lower levels of sex hormone,
with concomitant reductions in aggression and sexual potency and increases
in forward planning and family stability.
Despite the vast body of evidence now accumulating for important genetic
and behavioral differences among the three great macro-races, there is
much reluctance to accept that the differences in crime are deeply rooted.
Perhaps one must sympathize with fears aroused by race research. But all
theories of human nature can be used to generate abusive policies. And
a rejection of the genetic basis for racial variation in behavior is not
only poor scholarship, it may be injurious to unique individuals and to
complexly structured societies. Moreover, it should be emphasized that
probably no more than about 50 percent of the variance among races is genetic,
with the remaining 50 percent due to the environment. Even genetic effects
are necessarily mediated by neuroendocrine and psychosocial mechanisms,
thus allowing opportunity for benign intervention and the alleviation of
Richard Lynn. "Race Differences in Intelligence:
A Global Perspective." Mankind Quarterly, 31 (1991), 255-296.
Richard J. Herrstein and Charles Murray. The Bell Curve.
New York: Free Press, 1994.
David C. Rowe. The Limits of Family Influence. New York:
J. Philippe Rushton. "Race and Crime."
Canadian Journal of Criminology, 32 (1990), 315-334.
J. Philippe Rushton. "Cranial Capacity Related
to Sex, Rank, and Race in a Stratified Random Sample of 6,325 U.S. Military
Personnel." Intelligence, 16 (1992), 401-413.
J. Philippe Rushton, David W. Fulker, Michael C.
Neale, David K.B. Nias, and Hans J. Eysenck. "Altruism and Aggression:
The Heritability of Individual Differences." Journal of Personality
and Social Psychology, 50 (1986), 1192-1198.
Mark Snyderman and Stanley Rothman. The IQ Controversy,
the Media, and Public Policy. New Brunswick, N.J.: Transaction Publishers,