And the point is, what exactly? All of these genes are well known to be involved in steroid metabolism.

Off topic, but has anyone looked at this new paper on the 'warrior gene'? It doesn't seem to provide any new research, but relies on a paper by Widom and Brzustowicz suggesting that the effect of the low activity variant of MAO-A may be different for non-whites.


http://review.mai.ac.nz/index.ph...le/view/222/ 243

http://www.scoop.co.nz/stories/P...0909/ S00156.htm

Well the Maori can't have it both ways.

Up till this MAO-A cotroversy first appeared the cultural zeitgeist of NZ was that the Maori were a Warrior race. ( a good thing, denoting skill bravery, a certain machiavellian in your face-ness) Think Zulus , Ghurkas, Vikings.
Now with added side-connotations it is suddenly a bad thing.
NZ is now the most PC-riddled country in the world, any study in NZ, or by a NZer on the subject is career-endangering folly.

Interesting to see the numbers on this. Athletes sometimes like to argue about the role of genetics in success, especially as it relates to the ability to build muscle. This gives us some real numbers to drag into those arguments.

Chi,

The Gary Hook "essay" is hilarious. How ironic that those who believe that race is a social construct want us to believe that this gene acts differently in "non-whites." In fact, Widom and Brzustowicz suggested that biological racial differences could explain their finding of no protective effect from the 4-repeat MAOA VNTR allele in non-whites. They wrote, "given the differences in the allele frequencies in the white and non-white populations for the MAOA VNTR promoter polymorphism (observed in this study), as well as other polymorphisms within the MAOA gene and throughout the genome, it could be that there are substantially different frequencies of other MAOA modulating polymorphisms in white and non-white populations." Hook did not pass along that idea, preferring to only mention possible "environmental stressors." He criticizes applying what we know about the MAOA gene to Maori, yet he thinks that what Widom and Brzustowicz determined about "non-whites" can be generalized to include Maori.

Let us be clear. Widom and Brzustowicz did not prove that MAOA acts differently in non-whites. They only included 98 non-white males in their study. In contrast, Huang et al included 110 blacks, 10 Asians, 79 Hispanics, and 8 "other." Huang et al found that MAOA influences impulsivity. Beaver et al included 383 blacks and 1484 whites, and they found that MAOA influenced violent behavior. Weder et al included just 58 black and biracial subjects, but they found that the MAOA-environment interaction effect on aggression was significant specifically in that group. Of course, all these studies have somewhat low power, but the point is that Widom and Brzustowicz did not prove MAOA acts differently in non-whites. Even within their tiny 98-subject group of non-whites, they claimed that a sub-group of blacks also lacked a significant gene-environment interaction effect. They did not bother to offer numbers for how many of these mere 98 non-white males were black, even though a significant portion of the subjects were from a previous study in which 98% of the non-whites were white or black. They were hiding this information because their data suggest that blacks, compared to whites, have an order of magnitude more of the 2-repeat MAOA VNTR, which is far more likely to predispose to violence than the 3-repeat allele that earned MAOA the "violence gene" label.

For his part, Hook does not seem to understand the difference between the 3-repeat allele and Brunner syndrome, which completely shuts off MAOA. He thinks Brunner syndrome could not offer Darwinian advantage. Therefore, a more modest level of aggression from the 3-repeat allele would not, either. This was a poorly written attempt to browbeat scientists, much like the recent Catherine Elton essay in Time.

The Ahn et al study on hormones is relevant to MAOA because hormones influence MAOA expression. I am working on some analysis about it that I will post shortly on my blog. In the meantime, you can read what I wrote about Widom and Brzustowicz back in June.

I mistakenly wrote that 98% of the non-whites were white or black. Please note that it should read "98% of the subjects were white or black."

Here is the link to Catherine Elton's essay.