http://www.abc.net.au/worldtoday/content/2012/s3498036.htm?site=perth
Scientists at King's College London scanned the brains of 66 prisoners who had been diagnosed as psychopaths, and found significantly less. grey matter than normal in major areas of their brains.
MEREDITH GRIFFITHS: So this work that's just been published how significant do you think it is that the people who had the antisocial personality disorderliness and psychopathy, that their brains actually had less grey matter in certain areas than the other men that were studied? How significant is it to actually have less grey matter in a part or parts of your brain?
ADRIAN KELLER: The significance is that the frontal and temporal lobes of the brain are critical for the development of judgement and moral reasoning and our capacity to understand the emotional experiences of other people. Therefore you might expect that a reduced grey matter in these areas could reflect a reduced capacity to develop these critical emotional skills.
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It's certainly very powerful evidence that psychopathy is distinct from the more poorly defined anti-social personality disorder, as a more discreet clinical entity. And I think that tallies with clinical experience that the psychopathy construct is a better defined construct, it's more useful clinically, and therefore can be identified biologically in a way that anti-social personality disorder as a more global, perhaps more amorphous clinical entity cannot be defined.
http://www.abc.net.au/worldtoday/content/2012/s3498036.htm?site=perth