CRIME GENES

摘要

Reducing a convicted murderer's sentence because they have certain genes sounds a little far-fetched, but it has already happened. In Italy and the US, a common genetic variant, present in around a third of Caucasian men, has been successfully used inthe defence of violent criminals. Yet both the science and the ethics of the issue are still very much under debate.The variant in question is an allele conveying low activity of monoamine oxidase A (MAOA)1, an enzyme involved in regulating the metabolism of several neurotransmitters, including dopamine and serotonin, which influence brain function (Shih etal., 1999).