Anatomy of evil

You are judging a case of a man charged with child molestation.  His wife found a stash of child pornography in a cupboard, and was horrified to discover he had been making sexual advances towards his 11-year-old step-daughter, as well as soliciting prostitutes in massage parlours.  Worse, he is a policeman and school-teacher, supposedly a pillar of society, but as many people testify he has recently become increasingly impulsive and unable to resist urges – often resulting in highly immoral behaviour.  What sentence do you recommend for him?

The night before the sentencing, he complains of headaches and goes to hospital, where he is given an MRI scan.  Neurologists find a brain tumour in his orbitofrontal cortex, supposedly the seat of social behaviour and impulse-control, and say this could be responsible for his depraved behaviour.  Does your sentence change? 

This is roughly what happened in the case of a 40-year-old man in Kansas in 2002 (the story was reported in the New Scientist here).  He wasn’t given a jail sentence after the diagnosis, and his behaviour went back to normal after the tumour was removed.  This is something that would not have happened 20 or 30 years ago, before the advent of neuroimaging techniques that allow us to examine the brain in far more, high-definition detail than has been possible before.  Neuroscience is changing the way we see evil; the presence of a brain tumour, to most people, means less culpability should attributed to the perpetrator.  But how much does neuroscience know about what causes people to commit terrible acts, and does that excuse criminals from their deeds?

Psychopathy (closely related to antisocial personality disorder) is the classic, Jekyll-and-Hyde type of evil, characterised by callousness, lack of remorse and incapacity for love; maladaptive personality traits that tend to last a lifetime and very often lead to senseless violence, arson and exploitation of others.  Neuroimaging studies have shown that psychopathic patients have an underactive amygdala, a brain structure which normally responds to fearful or sad facial expressions: in other words, they appear to lack the ability to empathise with other people’s emotions, although they might understand perfectly well how people behave (leading to a tendency to exploit and manipulate people to their own ends).  Psychopaths don’t respond emotionally the way that healthy people do to ideas, words or images that normally elicit strong emotional reactions – puppies, happy couples, injured people.  Psychopaths treat all of these things as neutral, devoid of emotional content.  There is also suggestion that it is associated with frontal lobe abnormalities, as with the Kansas man earlier. 

Popular science writer Simon Baron-Cohen has written a book arguing for the view of evil as a lack of empathy (Zero Degrees of Empathy), which would explain the psychopathic tendency to commit serious destructive crimes – including murder – out of pure self-interest or just boredom.  But empathy can’t be the whole story.  Lack of a theory of mind, or insight into how other people think and feel, is characteristic of autism and a prerequisite of empathy; but cruelty is not an autistic trait.  There must be something other than an inability to empathise which drives psychopathic people to malicious behaviour and not autistic people, although current research falls short of confirming what this might be.

So in the light of such neuroimaging evidence, how far can “evil” like this be considered a brain disorder, the way a tumour can?  And does this excuse malevolent or criminal behaviour?

In British law courts there is the idea of diminished responsibility as a defence which can go some way to absolving a defendant of their acts.  This is a broad term which can include any abnormality of mental functioning: paranoid schizophrenia, epilepsy, sleepwalking, and so on.  Increasingly, psychologists and neurologists are being brought in as expert witnesses to legal cases and judgements of culpability are being influenced by new knowledge about the physiological underpinnings of criminal behaviour, as in the case of the Kansas man, particularly because to many people if something shows up on a brain scan it’s no longer the premise of personality or free will.

The question is how far the “my brain did it” defence can be taken – legally or morally.  At what point does free will step in?  Clarence Darrow, an attorney defending two young men charged with murder, famously made a similar case in Illinois in 1924.  He argued that his clients, who had spent months planning the kidnap and murder of a 14-year-old boy purely as an intellectual exercise, were the products of a long list of external factors to their upbringing: their emotional immaturity, glandular abnormalities, education in Nietzsche’s philosophy of the übermensch.  “Life is a series of infinite chances,” is what Darrow argued; every event in the universe, including every act people make, is the product of a web of causality or an accident of fate.  It was by chance that the two defendants came together, and it was by chance that they were taught Niezschean thought, and without these chance events the crime would not have been committed.

Darrow succeeded in getting his defendants a more lenient sentence than they would have got – they escaped the death penalty.  But extending Darrow’s deterministic view further, every act that people commit, every instance of evil, can be put down to a person’s upbringing or genetically inherited personality traits, or the series of chance events that puts them in a particular situation at a particular time and allows the act to happen.  Where does free will come into this?  Or, to take a 21^st-century reincarnation of the riddle, if everything you do is mediated by your brain, where does brain function stop and free will start?

In folk neuroscience there is a conception that at some point, brain malfunction overrides free will and cases like the Kansas man’s or psychopathy appear.  But this is not quite true; brain function underlies everything we do: the good, the bad, and the utterly mundane (or else what is operating your muscles to move, or allowing you to proceed from one thought to the next?).  It’s a fact that lies implicit in every theory of human behaviour and the human condition – law, psychology, philosophy, economics.  As many neuroscientists and philosophers argue, this doesn’t undermine the idea of free will; it’s just an interpretation of how free will works in terms of neural connections.

It is undisputed that new research in the brain sciences is having an increasing effect in the law courts, and there are worries over whether juries are capable of understanding the significance of such medical evidence that might be presented to them, not least because of the tendency to think that if something’s in the brain, it’s not a person’s fault.  An understanding of how brain abnormalities produce impulsive or immoral behaviour is changing how we think of “evil” – but whether this knowledge can relieve perpetrators of responsibility, or even eradicate   the old-fashioned conceptions of evil and morality – remains to be seen.

Emma Roscow