Blacks commit violent crimes at far higher rates than most other races, including whites and asians. Wherever blacks make up a significant percentage of the population, overall violent crime rates tend to be higher. It would be natural for someone of a scientific bent to look for genetic causes, when such a widespread and consistent behavioural phenomenon is seen in a particular population group.
A few years ago, a great deal of attention was given to the discovery of “The Warrior Gene,” the MAOA allele containing a 3 repeat region in its promoter region. This gene causes lower activity of the monoamine oxidase enzyme, and allows for much higher levels of monoamine neurotransmitters in the brain. These higher levels of neurotransmitters have been associated with higher rates of violence under certain circumstances. The MAOA 3R allele is more prevalent in black men than in whites.
But very little attention was given to the MAOA allele containing a 2 repeat region in the promoter. Research has shown (see below) that the prevalence of the 2R MAOA promoter allele in black men may be over ten times the prevalence of the 2R allele in white men, and over 100 times the prevalence in Asians.
The frequency distribution of variants of the MAOA gene differs between ethnic groups. 59% of Black men, 56% of Maori men, 54% of Chinese men, and 34% of Caucasian men carry the 3R allele. 5.5% of Black men, 0.1% of Caucasian men, and 0.00067% of Asian men carry the 2R allele. __Wikipedia article “Monoamine oxidase A and the Warrior Gene
Another estimate of the prevalence of the 2R allele by race is mentioned below:
According to earlier research, the violence-promoting tendencies of the MAOA 3R allele will not be triggered unless the male suffered from child abuse when young. Whether this association will hold up in further research — and whether it is actually a limit on the violence-causing activity of the MAOA 3R allele — is a question best settled by careful science. But the MAOA 2R allele — while much less common — seems to be under no such constraints.
Keep in mind that behaviour is influenced by multiple genes, but if it is true that roughly 5 – 10 % of black male genomes contain the potentially more dangerous MAOA 2R allele, how much of black crime overall might be “attributed” to this gene?
If only those who possess the 2R allele were especially prone to violence, we might expect to see an incidence of violent crime among black males of 5% or less. But if each violent offender is prone to commit multiple crimes before (and after) incarceration, the number of violent crimes committed by this small minority of black males could accumulate in an impressive manner over time.
Greg Cochran estimates that at any given time in the US, about 2.2 million black males are in prison, for a variety of offenses. That is far more than 5% of US black males, and even allowing that many of those offenses may not have been of a violent nature, it is clear that a higher number of black males are guilty of violent crime than could be explained by the prevalence of the 2R allele among black males.
This becomes particularly clear when one contemplates the ongoing black violence that continues to occur at an increasing rate in many urban areas, despite the incarceration of the above-mentioned 2.2 million black males.
Clearly both the population of black males behind bars, and the population of black males on the streets, contain a mixture of 2R and 3R MAOA alleles — and perhaps a few 3.5R and 4R alleles as well. So one could not blame the entirety of black violent crime on the 2R allele directly.
But what are the indirect effects on violent crime of an individual with the 2R allele? Violent gangs tend to coalesce around the most violent individuals. Gang leaders and other particularly violent criminals can become role models, using peer pressure to instigate heinous acts of violence which most of the individual members of the group might not have considered on their own.
In childhood, violent bullies on the schoolyard or in the neighborhood can make life hell for other children who would rather experience a “normal non-violent childhood.” These bullies likewise act as role models and magnets for other lads and girls who may feel a natural resonance with their violent behaviour.
Thus the 2R allele may have a “multiplicative effect” on group behaviour, far above its meagre prevalence within the population.
The only way to answer these questions is through careful and extensive genetic and forensic research, with free access to the involved populations of offenders and potential offenders given to scientific study.
Unfortunately, careful research in this area is not being widely funded by the US federal government, even though the federal, state, county, and municipal governments would benefit immensely from a better understanding of the origins of the violent criminal impulse.
Massive denial caused by political correctness and other counter-productive ideologies tends to hamstring the best efforts of science when attempting to understand race and gender based differences.
The end effect of this failure to carefully study crucially important population phenomena, could very well be cataclysmic. At the least, it is likely to be tragic.
For further study: