Dr Nigel Blackwood, Kings College London
One in five violent offenders are what psychiatrists would describe as psychopaths. They’re callous, unemotional and from childhood show violent tendencies. They’re also responsible for a disproportionately large amount of crime. But a big problem dealing with psychopathic criminals is that punishments - like prison - usually offer no deterrent to re-offending. Now Nigel Blackwood and his team at Kings College London, have discovered that this may be because their brains are wired up differently. He explained to Kat Arney what defines a psychopath...
Nigel - Psychopaths are individuals who have been involved in anti-social behaviours across their lifespan. They're conduct disordered as kids with what we call callous-unemotional traits and grew up to be adult psychopaths. So, in common with the broader anti-social group, they have a lifespan history of impulsivity, risk-taking behaviours, poor decision-making. So, they lack in empathy. They're callous. They're interpersonally manipulative. They use aggression in an instrumental way to get what they want.
Kat - What's the wider impact to society of these kinds of people?
Nigel - So, the broad anti-social group, a small number of men are responsible for the vast majority of offending behaviours in our society today. That psychopathic subgroup are likely to start offending earlier have a higher frequency of offending behaviours, and are most likely to re-offend when they're released from prison. So, that's a very important group to try and intervene in.
Kat - How did you go about in trying to study this group of people in more detail?
Nigel - So, there's plenty of studies that look at the differences between psychopath’s brains and normal subjects in the community. But if we really think there's something important about psychopathy, we’ve got to show that there's differences between people who are antisocial and psychopathic and those who are antinsocial are not psychopathic. So, we looked at 50 men, some from the community, and the vast majority of coming out of prison and to being looked after in probation services. We made sure that they had violently offended in the past, so they've been involved in murder, attempted murder, GBH, rape, and then decided whether they were or were not truly psychopathic. And then we looked at the differences in those three groups in our brain scanner.
Kat - What did you find that was different between them?
Nigel - Well, I suppose there's a folk idea that the psychopathic group don't respond to punishment, just because there's reduced sensitivity to punishment. They have years of being punished by their parents, by their teachers, by the prison system, and they just don't respond anymore. But that isn’t what we found. So, we found at the moment at which the psychopathic group were punished in a task which involved reward and punishment, they showed increased activity in areas that track such information. So, they're not just reduced in the sensitivity to punishment. There's something fundamentally different about the way they process punishment information.
Kat - To play devil’s advocate slightly, if this is something that's just intrinsic in the way someone’s brain is wired up, you're wired to be a psychopath, why don't we just keep them imprisoned forever?
Nigel - Well, we know that this subgroup are more genetically vulnerable, but we shouldn’t pessimistic at this stage that these kids are doomed from the womb and we’ve got to preventatively detain them. What we need to be trying to fix is changing the treatment programmes. And I think we can maintain at least some sense of therapeutic optimism about our approach to such people.