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Genes made me do it: genetics, responsibility and criminal law

Genetics is just the latest specialist knowledge threatening to take the question of criminal responsibility away from law and hand it over to science. Graham/Flickr, CC BY-NC-SA

Welcome to Biology and Blame, a series of articles examining historical and current influences on the notion of criminal responsibility.

Today, Arlie Loughnan considers the challenge to the legal system posed by genetic science.

It’s not much of an exaggeration to say we’re in the midst of a crisis in criminal responsibility.

Society is becoming more aware of what causes people to commit crime. The range of causes includes addiction, a history of sexual or physical abuse, and “rotten social backgrounds”, as they say in the United States.

How, then, under these conditions, can we still call people to account for their actions in court, on the basis they acted freely and voluntarily when they committed an offence? Do we have to throw away ideas of responsibility for crime?

The heart of the law

Criminal responsibility is the conceptual core of criminal laws: it allows us to hold a person accountable for his or her conduct, and justifies punishment if they’re convicted.

Criminal responsibility is different to criminal liability, which concerns the outcome of a trial. Rather, it relates to whether a person is properly recognised as a subject of the law, or put another way, whether it’s appropriate that he or she is held to the moral standard of behaviour criminal laws encode.

Our notion of criminal responsibility centres on a person’s mental state – what the accused knew, thought or perceived. We construct the defendant as an abstract, rational entity – made up of a set of capacities or exercising a set of choices – and abstracted from his or her social and political context.

Genetic science is threatening ideas about criminal responsibility. Esther Dyson/Flickr, CC BY-NC

This approach reflects the influence of psychology on the historical development of the principles and practices of criminal law.

Now, genetic science – in this context, the influence of genes on human behaviour – is threatening or promising (depending on your perspective) to render criminal responsibility – and the ideas about blameworthiness or culpability at its heart – null and void.

Research suggests genetic as well as shared environmental influences are important factors in persistent antisocial behaviour. On the face of it, such research appears incompatible with beliefs about individual choice on which criminal law rests.

Genetic science does indeed pose a challenge for criminal law. It’s not possible or desirable to ignore developments in scientific knowledge, for the legitimacy of criminal law practices if nothing else. But genetic science isn’t yet living up to its promise – or threat – to overwhelm current practices.

Evidence from the United States, where the effect of genetics on crime has been hotly debated, indicates limited use. In particular, “gene evidence” appears to be brought into the courtroom by defence counsel, rather than prosecution, and to be used for mitigation at sentencing, rather than at the point of conviction.

As this suggests, the impact of this evidence is modest, and it’s being integrated into existing criminal practices.

A deeper understanding

It should also be remembered that genetics is the latest in a long line of specialist scientific knowledges that have promised or threatened to take the question of criminal responsibility away from law and hand it over to science.

Neuroscience, with its ability to produce a picture of the living brain, and cognitive psychology, with its insights into higher mental processes, have also claimed some territory.

Whether a particular genetic disease or condition impacts responsibility for crime is an entirely separate issue to having the genes. Gabriela Ferreira/Flickr, CC BY-NC-SA

And older ideas drawn from eugenics (about the degeneracy of particular families and whole populations) and phrenology (famous for its focus on the size and shape of the heads of criminals), for instance, were once thought to have all the answers to the problem of crime.

What’s all too easily lost in this perennial debate about science and criminal responsibility is an appreciation that legal evaluation of responsibility for alleged criminal conduct is not merely a mechanical exercise. Ideas of causation are not the same in law as in science.

A particular configuration of genes (or, more accurately, the interaction of those genes and the environment) may cause a particular disease, for instance, but whether the disease impacts responsibility for crime is an entirely separate issue.

Criminal responsibility is about factors such as someone’s appreciation of wrongfulness of their behaviour rather than genetic predisposition or tendency. And appreciation of wrongfulness doesn’t readily reduce to the configuration of genes.

Assessing responsibility for crime is a moral-evaluative task, one in which lots of different types of evidence – scientific and non-scientific – is taken into account.

At the end of the day, where the individual faces a serious charge, this evaluation is undertaken by a jury of lay people whose role is precisely to weigh all the evidence – and apply their (not expert) knowledge in evaluating an individual.

This is the first article in our series Biology and Blame. Click on the links below to read other pieces:

Part two – Irresponsible brains? The role of consciousness in guilt

Part three - Psychiatry’s fight for a place in defining criminal responsibility

Part four – Looking for psychopaths in all the wrong places: fMRI in court

Part five - Why shouldn’t addiction be a defence to low-level crime?

Part six – Natural born killers: brain shape, behaviour and the history of phrenology

Part seven - Put down the smart drugs – cognitive enhancement is ethically risky business

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