Neuroscience and the Law

Neuroscience is revolutionizing our understanding of how the brain works. In the process it is challenging ago-old ways of thinking about crime and punishment. Some neuroscientists even say that it’s time to completely rethink our judicial system in light of their discoveries. That’s because our current legal system presupposes a certain picture of how the mind works that many neuroscientist now believe is almost entirely wrong.
This week, our topic is neuroscience and the law. Neuroscience is revolutionizing our understanding of how the brain works. In the process it is challenging ago-old ways of thinking about crime and punishment. Some neuroscientists even say that it’s time to completely rethink our judicial system in light of their discoveries. That’s because our current legal system presupposes a certain picture of how the mind works that many neuroscientist now believe is almost entirely wrong. Common sense counts a person morally responsible for a wrongful action only if the action results from their free, conscious, deliberate choice. Pretty much the same idea is expressed in the law via the concept of a guilty mind or mens rea. Under the law, an act can’t make you guilty unless your mind is guilty too.
There are, of course, exceptions to this last claim, since, to be precise, the law distinguishes several different modes of culpability — strict liability, negligence, recklessness… A wrong doer doesn’t have to make a free, conscious, deliberate choice to be culpable in these lesser ways. But the main point still stands. The law sharply differentiates between actions we freely, consciously, and deliberately choose and actions that we don’t so choose. It holds us most responsible and punishes us most severely for actions of the former sort.
Modern neuroscience purports to throw cold water on the idea that we freely choose our actions. And neuroscience teaches us that most of what the brain does to cause behavior happens without the benefit of conscious deliberation at all. Conscious deliberation is at best the small tip of a really huge iceberg. And the stories we tell ourselves about the causes of our behavior, according to some neuroscientists, are just after the fact confabulations, with no real basis in the neural facts of the matter.
I have to admit, though, that I’m not quite sure the story is as simple as I’ve just suggested or that there is really such a direct conflict between common sense and the law, on the one hand, and the deliverances of neuroscience, on the other. That’s because all that the law really needs is the distinction between doing something on purpose, in full awareness of the consequences of the action, on the one hand, or doing something out non-culpable ignorance or doing something because your neuronal circuitry is misfiring, on the other. As long as we can make such distinctions, the law has all it needs in the way of freedom, consciousness and criminal culpability. Think of the difference between me – a relatively normal person with a relatively intact brain – and, say, a paranoid schizophrenic. Surely, neuroscience doesn’t show that, as far as the law is concerned, we all might as well be paranoid schizophrenics.
The problem with this approach, though, is that neuroscience simply refuses to draw sharp lines. As far as neuroscience is concerned, it’s all on a continuum. Take a supposedly normal, law abiding citizen, upset their dopamine or serotonin balance just a teeny-tiny bit, or make a tiny little lesion in just the right place in their neural circuitry and presto-chango you’ve turned your upstanding law-abiding citizen into a viscous criminal.
This is not to suggest that all criminal behavior is the result of bad neural chemistry and circuitry and is, therefore, excusable. To be sure, all human behavior –- every bit of it — is the result of our neural chemistry and circuitry. The point is that relatively small differences in our brains can make huge differences in our behavior. And since we don’t have much direct, conscious control over our neural chemistry and circuitry, we have less much direct conscious control over our behavior than the law imagines.
Even so, it doesn’t directly follow that we should necessarily excuse criminal behavior. Think of we do we with other sorts of bad outcomes that are caused by chemical imbalances or bad wiring? We treat them with medication or therapy or surgery. One day soon we’ll be able to do the same when bad brain chemistry leads someone to perform criminal acts. And punishment need not be ruled out altogether either – though it probably needs a new basis. Typically with think of punishment is retribution. But if there is no such thing is freedom, if conscious, purposeful deliberation is just an epiphenomenon and not where our behavior is really and truly generated, then perhaps nobody really intrinsically deserves to be punishment.
But there is another possible basis for punishment – one that may be of more neurologically sound. Punishment provides negative feedback. And the brain sometimes changes itself in respond to negative feedback. Perhaps neuroscience can help us learn which forms of punishment provide effective feedback and which don’t.
Lest you think I’ve simply swallowed the neuroscience Kool-aid, I should say that there are still lots of questions we need to address before I’m willing to drink it down gladly. For example, I worry that everything I’ve been saying so far presupposes a philosophically problematic – I won’t say naïve — concept of freedom – what philosophers sometimes call contra-causal freedom. That’s a kind of absolute and total freedom that leaves our actions entirely and exclusively up to the will. I admit we don’t freedom in that sense. And maybe neuroscience can help us to see that. But I strongly doubt that either common sense or our legal system presupposes that we have freedom in that sense. And if we don’t there is no real conflict between our criminal justice system and what neuroscience is telling us about how the brain causes behavior. Is there?
Photo by Robina Weermeijer on Unsplash