Letās look at a culture without race and see what cognitive ability does to crime.
Hakan Stattin and Ingrid Klackenberg-Larsson followed 122 Swedish males from ages three though thirty. They measured IQ at ages three, five, eight, eleven, fourteen, and seventeen and counted the number of registered criminal offenses through age thirty. Frequent offenders, those men with four or more criminal offenses, averaged IQ scores of only 91 points; sporadic offenders averaged 97 IQ points; and nonoffenders averaged a full 102 points. Remarkably, IQ at age three significantly correlated with registered crime at (Spearmanās) rho = -.25. IQ at the later ages also correlated with crime at around rho = -.20.
Scott Menard and Barbara Morse studied 257 high school students in San Diego, California, measuring both IQ and self-reported delinquency. IQ was correlated with nonserious crimeāsuch as petty theft, liquor violations, vandalism, truancy, and running awayāat r = -.08. IQ was correlated with serious crimeāsuch as gang fights, auto theft, grand theft, and robberyāat r = -.16.
Another source
The majority of studies have found IQ differences between offenders and nonoffenders (e.g., Ellis &Walsh, 2003). On average, the IQ for chronic juvenile offenders is 92, about half a standard deviation below the population mean. For chronic adult offenders, however, the average IQ is 85, 1 standard deviation below the population mean. A study of Texas inmates who entered the prison system in 2002 indicated that approximately 23% of the inmates scored below 80, almost 69% scored between 80 and 109, and only 9.6% scored above 110 (Ellis & Walsh, 2003).
And then once they are incarcerated:
The interesting thing about the last one to me is this:
Diamond, who is earning a Ph.D. in criminology, said an individualās IQ captures the ability to navigate a social environment in addition to assessing academic capabilities.
Which I donāt believe is limited to the incarceration environment. The same stressors exist outside.
āItās not too surprising then that people who are deficient in these regards would be more prone to respond physically and lack an advanced repertoire for handling situations,ā she said.
Indeed itās not.
āItās more about IQ playing a role, and that itās not only about a particular personās IQ, but itās about collective IQ in an environment of confinement.ā