Causes of violence: Take 2

Lee, T., Chan, S., & Raine, A. (2008). Strong limbic and weak frontal activation to aggressive stimuli in spouse abusers Molecular Psychiatry, 13 (7), 655-656 DOI: 10.1038/mp.2008.46

Raine, A. (2008). From Genes to Brain to Antisocial Behavior Current Directions in Psychological Science, 17 (5), 323-328 DOI: 10.1111/j.1467-8721.2008.00599.x


If the name Adrian Raine sounds familiar to you, then congratulations! You were paying attention. Raine was part of the USC group we had talked about in class – the one with the English accent, remember? Though Raine is now at the University of Pennsylvania, he's still putting out high-quality research looking into the biological bases of criminality.

Case in point: his 2008 paper with Lee and Chan. This was an imaging study performed to look for neurological differences between men who abuse their spouses and those who don't. Their idea is that men who tend towards battery are less able to control their reactions to negative emotions, and thus more likely to act on them – violently. This study relied on the old psychological standby of inhibition, the Stroop task. However, they also used a modified Stroop that focused on emotional content. What they found was that the abusers weren't any worse than the controls on the basic Stroop task, but when emotions were brought in they suddenly became significantly slower to react. This was reinforced by the fMRI data, which showed both less activity in prefrontal regions, responsible for control and inhibition, and greater activity in limbic regions (associated with emotion) including the cingulate gyrus and hippocampus.

So there are psychobiological distinctions between men who do and do not abuse their spouses. This is fantastic!, right? We can just do brain scans on suspects to determine whether or not they're at high risk of offending and separate them – maybe for treatment, maybe just for the protection of society. Well, if you're still excited about these possibilities (and I would have hoped that my neo-Orwellian rhetoric would have turned you off by now), let me refer you to his second paper, published in Current Directions in Psych. Science. Here, Raine quickly sums up where we stand in the nature/nurture dialogue (it's not a debate anymore) on antisociality: “...the field is now moving on to the more important, third-generation question: ‘Which genes predispose to which kinds of antisocial behavior?'” Part of that answer is mutations in genes like MAOA leading to behavior like deficits in moral reasoning.

However, there are two critical things to remember: one, that genes only code for proteins (usually), and not for specific behaviors; and two, that biology is not destiny. Raine points out that there are epigenetic factors that help determine an ultimate phenotype. The idea that what's coded in DNA doesn't exactly translate to biological manifestations isn't new, but it's easy to forget. However, things like diet or hormone levels in pregnant mothers can and do have life-long consequences in terms of development. Raine brings up some pointed ethical questions in his penultimate paragraph that should sound familiar to anyone who's studied or thought about genetics and behavior. The only thing I'll add to that is a reminder to exercise restraint when interpreting any study that claims to have found a link between some gene and... well, anything, really.