Statistically high rates of violence accompany population groups of African descent wherever they go. From the townships of South Africa to the ghettos of Detroit and Philadelphia to entire nations such as Haiti or Jamaica -- there is a close relationship between statistically high rates of violence and the high prevalence of persons of African descent.
Why are blacks so violent -- statistically -- wherever in the world they go? The answer to the question is as complex as the human genome -- and the close, complex interaction between the genome and the environment.
A few of the genetic pieces of the puzzle may slowly be falling into place. Take the so-called "warrior gene," for example. This variant is found in black males almost 10 X more frequently than in white males. This "warrior gene" is actually an abnormal "promoter" for the monoamine oxidase A (MAOA) gene. This abnormal promoter has the effect of reducing the activity of monoamine oxidase enzyme, which results in more of the monoamine transmitters (serotonin, norepinephrine etc) in the brain -- leading to agitation, impulsiveness, and other dysfunctional behaviours.
We examine the effect of the 2R allele of MAOA on a range of antisocial outcomes. ► The 2R was related to arrest, incarceration, and lifetime antisocial behavior. ► These associations were only observable for African-American males. ► Only 0.1% of Caucasian males carried the 2-repeat allele. [ed: compared to about 10 times that proportion of African American males with the 2-repeat allele]_SourceIt is important to understand is that there is not just one "violence gene" or "warrior gene" that can explain the high rates of violence seen among black populations. Multiple genes are involved, as well as multiple environmental interactions with the genes, arising from within the person himself, and from his environment.
A functional VNTR polymorphism in the promoter of the monoamine oxidase A gene (MAOA-LPR) has previously been shown to be an important predictor of antisocial behavior in men. Testosterone analogues are known to interact with the MAOA promoter in vitro to influence gene transcription as well as in vivo to influence CSF levels of the MAO metabolite 3-methoxy-4-hydroxyphenylglycol (MHPG) in human males. We examined the possible joint effects of testosterone (measured in CSF) and MAOA-LPR genotype on antisocial personality disorder and scores on the Brown–Goodwin Aggression scale in 95 unrelated male criminal alcoholics and 45 controls. The results confirm that MAOA genotype and CSF testosterone interact to predict antisocial behaviors. The MAOA/testosterone interaction also predicted low levels of CSF MHPG, which tentatively suggests the possibility that the interaction may be mediated by a direct effect on gene transcription. _Interaction of Testosterone w/ MAOA Promoter geneThere are many important subtleties to keep in mind. An abusive childhood, for example, is more likely to "activate" abnormal behaviours that may be potentiated by particular gene allele forms. The importance of environmental "provocations" should also be kept in mind.
We report an experiment, synthesizing work in psychology and behavioral economics, which demonstrates that aggression occurs with greater intensity and frequency as provocation is experimentally manipulated upwards, especially among low activity MAOA (MAOA-L) subjects. In this study, subjects paid to punish those they believed had taken money from them by administering varying amounts of unpleasantly hot (spicy) sauce to their opponent. There is some evidence of a main effect for genotype and some evidence for a gene by environment interaction, such that MAOA is less associated with the occurrence of aggression in a low provocation condition, but significantly predicts such behavior in a high provocation situation. _MAOA Predicts Aggression
Even between persons with similar genetic complements, there will likely be different levels of provocation required before violence is resorted to. Genetic variants can make a person more sensitive to stress, with a lower "violence threshold."
There are also cognitive factors involved, including fear of punishment, and the calculated probability of being caught and punished.
In addition, when a person thinks he has little to lose and more to gain, he is more likely to choose actions that may lead to violence. He is more likely to make such choices when he is relatively comfortable with the idea of violence, or when low levels of intelligence / executive function combine with high levels of impulsivity to block out the possible consequences of his choices.
Even with the limited evidence available so far, it is possible to hypothesise that high impulsivity -- at least partially due to genetic causes -- can combine with higher testosterone levels, lower IQ, poorer EF, and environmental provocations to lead to higher likelihoods of violent behaviour.
It is important to emphasise that when African American males are steeped in a culture of hatred toward persons of European or Asian descent from a very young age and throughout their lifetimes, that it is more likely that they will take violent action against such persons when given the opportunity to do so with minimal risk to themselves.
The Scribd document "MAOA Varies by Race" comes from a 2011 Comprehensive Psychiatry study which describes how the "more normal" variant of the MAOA promoter gene protects men of European descent from developing an antisocial personality -- despite being abused as a child. The study failed to demonstrate a similar protective effect for black boys and men.
Finally, the reason that the term "warrior gene" is a misnomer, is that a true warrior relies on a large number of skills -- including the ability to abstain from violence when it is not appropriate. The MAOA promoter gene variant described in studies above would not provide a battlefield warrior with any meaningful advantage -- and would likely prove disruptive to a disciplined warrior squad.
Interesting. I wonder what kind of environmental factors caused the adaptative behaviors that in turn caused the genetic predisposition?
ReplyDeleteMultiple genes are involved in any complex behaviour difference. Genes tend to mutate or otherwise change, and then the environment selects the winner of that genetic lottery. And so on.
ReplyDeleteThe variant allele in the MAOA promoter DNA probably came about for no particular reason. But there is a question as to why that allele would be selected for at higher rates in African populations.
One of the hypotheses is that men with this promoter variant tend not to maintain long term relationships, but rather impregnate multiple women throughout their lives. This might cause the variant promoter to be expressed across larger and larger parts of the population over time.
Men in general seem programmed to spread their seed far and wide, but men with the MAOA promoter variant as described in the papers may put more of their hearts and souls into it.
High illegitimacy rates in black populations are caused by several factors at multiple levels -- from genes to culture. The MAOA promoter variant may be one of the causes.
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ReplyDeleteThank you. I put some more thought into this. Here's another idea, and it happens to coincide with the MAOA phenomenon.
ReplyDeleteIt is my understanding that Homo Sapien emigrated out of Africa because of drought and scarcity of hunting opportunities. This makes it likely that those who ventured out had lower aggression levels that made them less able to compete for food. However, they had enhanced left-brain problem-solving abilities. These abilities gave them the confidence to leave a familiar environment and venture into the unknown, leaving their more competitive brothers to fight over the scarce resources on the African continent.
Those who ventured out (I think of them as the nerds of the Paleolothic era) had to develop cold-weather survival strategies such as the construction of sturdier forms of shelter and clothing. Most importantly, they had to develop their long-range planning skills. They no longer had to plan from day to day as they did in Africa, but rather, year to year.
In this more challenging environment, a smaller percentage survived. It was no longer a case of the strongest surviving, as it was in Africa; these cold-weather gene pools had to be downright elite.
In addition to the development of new cognitive skills, there had to have been an advancement in their social skills as well. A riskier survival rate would have called for a more pressing need to maintain harmony and close bonds within the group. (Close bonds will compel people to take risks for each other). Essentially, men would have felt less of a need to spread their seed liberally, and more compelled to keep their own "elite" family units strong and intact. In essence, he was now ploughing deep, not wide.
Additionally, men would have had to curtail their knee-jerk reaction to kill encroaching males. Instead, strangers would have been carefully evaluated. Possibly, they were a threat, but equally possibly, they might have knowledge to share, such as new methods of tool-making or herding patterns. Knowledge in these cold-weather regions was just as valuable a commodity as food. Thus, it behooved a man to view strangers as a possible opportunity and to use his social skills to form a rapport rather than to automatically kill them.
Presuming that Asian and Middle-Eastern man's adaptations were an intensified focus on the care and feeding of one family unit (as opposed to creating family units over a large geographical area), as well as a more measured and thoughtful evaluation of outside groups, the MAOA promoter within him would have had to adjust accordingly. Aggression toward encroaching males and liberal seed-spreading could actually impede his survival, not advance it.
Meanwhile back in Africa, there was no need for the MAOA promoter to adjust. Life was comparatively easy. If one family unit didn't survive, no worries. The conditions were such that a man could liberally spread his seed knowing that a comfortable percentage would survive. After all, the survivors were strong, but they weren't elite as their Asian and Middle-Eastern counterparts were. Thus, life on the African continent was a little more expendible.
Additionally, all encroaching males could safely be assessed as a threat and thus, automatically fought off. No evaluation was necessary because knowledge-sharing and rapport-building in this milder environment were not quite as imperative.
In essence, one subset of Homo Sapien had to adjust its level of aggression to its environment and the other subset did not.
I am not a scientist; I'm just postulating from my right brain. Feedback is wholeheartedly welcome, even from challengers. Thanks in advance.
Very interesting, thanks. How would you test your hypothesis?
ReplyDeleteThe MAO A gene is not the only neurotransmitter related gene to have variants in promoter regions that appear to influence aggressive behaviour under particular environmental conditions.
Behaviour differences related to these different gene forms appear as early in primate evolution as the rhesus monkey.
As population genetics grows in skill, the various politically correct social sciences are likely to feel more and more under siege by biological realities.
There is a need for more science journalists who are willing to report on this coming avalanche of findings -- despite the threat the findings pose to the reigning power of politically correct academic and political dogma.
Another possible impact on the genetics of cognition and behaviour, was the interbreeding between neandertals and homo sapiens outside of Africa. Some of the advantageous genetic traits you describe may have been evolved by neandertals before homo sapiens arrived on the scene, then transferred to homo sapiens as the parting gift of a fading species.
ReplyDeleteIntriguing. This could very well be, especially when you consider how quickly Neanderthal succombed to Homo Sapien's dominance. It's really remarkable that Neanderthal thrived in Europe for so long (260,000 years), however, immediately upon Homo Sapien's arrival, his numbers and territory began to diminish. He survived for just another five to thirteen thousand years before he was overcome.
ReplyDeleteA more passive genetic makeup could have contributed to Neanderthal's inability to stand his ground (coupled, of course, with the intellectual disadvantages which led to Homo Sapien gaining control of the most fertile hunting grounds).
Neanderthal, in those sporadic matings with Homo Sapien, could very well have contributed that mitigating balance of passivity. From a right-brain perspective, this is bittersweet. A parting gift indeed.