Tommy Morrison and George Foreman (Chris Gardner / AP).
Tommy Morrison and George Foreman (Chris Gardner/AP).

Brown university professor of political science Rose McDermott has a fascinating guest post over at Political Violence @ a Glance:

There’s a dirty little secret that academics don’t like to talk about but explains why some individuals choose to fight. Some people, especially some men, like to fight. They even like to kill.

McDermott identifies two primary factors that make some people more likely to fight than others: testosterone (a familiar and well-established claim) and, more controversially, genes:

To be clear, I am not, nor will I ever, claim that there is a “gene for” anything; such a construction betrays a deep misunderstanding of the nature of genetic pleiotropy, whereby it requires many genes in combination and in interaction with the environment, along a long trajectory of developmental processes, to produce any behavior. That said, when we examine the influence of particular factors on large populations, we can begin to see how particular genetic factors explain the variance between individuals. From this perspective, one of the few robust polymorphisms related to aggression is a low activity form of monoamine oxidase (MAOA). Because this is on the X chromosome, men are more likely to manifest the effects of this polymorphism if they have it.

We have written quite a bit on the study of genopolitics on the Monkey Cage before. My own view is that these non-deterministic genetic arguments are plausible but that I have no way to evaluate the validity of specific truth claims. I just don’t have the expertise, and very few social scientists do. This is important as there is increasing data availability of genetic variation across populations, and someone will (or more likely already has) correlated some of this with conflict data of sorts. All kinds of things can go wrong in interpreting the resulting correlations.

Luckily McDermott is a cautious and sophisticated guide. She does especially well in countering the claim that we don’t necessarily need to care all that much if our genes influence political behavior because there is little that we can ethically do about it (see here for a version of this argument by Larry Bartels on the link between genes and political views). To McDermott, the key is the interaction between the environment and genes:

Why would this matter? Likely because those environmental events provide cues that signal to the body that it needs to activate processes designed to increase the odds of survival in a threatening environment. If the environment is not threatening, you likely don’t need them, and they could get you into trouble. In addition, such aggression does not show up randomly. Rather, it occurs in the context of direct provocation, when an individual might feel threatened and need to fight to secure resources in a hostile social situation. In other words, the environment provides critical cues that allow for the activation of particular gene expression through epigenetic and developmental processes we are just now beginning to try to understand. Such individuals may, however, prove more likely to self-select into environments, such as the military, where fighting is not only allowed but encouraged.

I must admit that I still don’t fully understand the takeaway points. For example, toward the end she claims that:

However, if we look around the world, there is a lot of conflict. And not all of it results from injustice. Some of it emerges in hostile environments among communities who may not need to fight, but like to fight, for various reasons.

That sounds a bit more deterministic to me. Is the threatening environment not a precondition? If we find that prevalence of a specific gene in a group is correlated with more conflict, are we going to conclude that men in this group on average “enjoy” fighting more? Go read the whole thing (see here for another story on McDermott’s research).