Douglas Starr in Aeon:
[I]f you look at the totality of peer-reviewed studies of the past several years, it’s hard not to come to the conclusion that biology plays some role in criminal behaviour, impossible to quantify. The new science of epigenetics proposes an interaction between environment and heredity, in which environmental factors (such as childhood abuse) can affect the expression of genes. In other words, the nature-nurture division that scientists have been arguing about for more than a century is narrowing, and might someday disappear. Genes and brain structure do not represent a simple on-off switch that determines a person’s behaviour but, as some studies show, they can indicate a vulnerability. A temperamentally-impulsive young man who lives in deprivation and has been handed a gun is more likely to make a bad decision than an equally impulsive guy from a nice neighbourhood holding a tennis racket.
Raine has been studying brain scans for decades, and he has come up with a kind of grand unified theory of violence. He describes it with the phrase ‘from genes to brain to antisocial behaviour’. Certain gene abnormalities can lead to structural brain abnormalities that lead to emotional and cognitive abnormalities (such as poor impulse control) that can lead to anti-social behaviour. At the same time, he writes, early life experiences – including maternal neglect, poor nutrition, or being surrounded by gang violence – can feed into the cycle.
‘In this context,’ writes Raine, ‘how moral is it for us to punish many criminals as harshly as we do?’
Here’s where today’s researchers fundamentally diverge from their 19th-century forbearers, not only in the content of their research but its direction. No one is suggesting the existence of ‘born criminals’, or that such people need to be permanently locked away. Fallon posits a ‘three-legged stool’ model of psychopathy, involving genes, brain function and early childhood exposure to emotional, physical or sexual abuse. The one component we can affect – childhood violence – involves social, not biological, intervention. Raine and other criminologists propose that courts consider an alleged criminal’s genetic and neurological make-up prior to sentencing – not to impose lifetime segregation for someone with violent predispositions, but to include appropriate treatment and care.
More here.