No such thing as a born killer Against nature Nature trail is leading us off the path Of mice and men Doing what come naturally Natural order of things It ain't natural naturally?

Refutation: There is more to us than genes and environment, argues Kenan Malik

Two recent events have revived the debate about whether criminal behaviour is genetically determined. In the United States, Stephen Mobberley, a convicted murderer, is appealing against his death sentence on the grounds that his crime was the product of a genetic predisposition. In Britain, the prestigious CIBA Foundation is hosting a conference this week of geneticists, psychologists and anthropologists on "The Genetics of Criminal and Antisocial Behaviour". Both reflect the growing consensus that human behaviour can be seen in biological terms.

There are two main arguments put forward by advocates of a link between crime and genetics. First, they say, as genes are clearly responsible for natural attributes, why should they not also be responsible for human behaviour, including behavioural dysfunctions? And since we can influence animal behaviour through genetic manipulation, why not with humans? Second, they concede that genes do not determine criminal behaviour, but they argue that our genetic heritage works together with environmental factors to influence behaviour.

So far, attempts to link specific human behaviours to specific genes have failed woefully. Over the past decade researchers have claimed that schizophrenia, alcoholism, manic depression and violence are all linked to particular genetic defects. In each case, the claim has been shown to be false. There are, however, deeper problems with the attempt to link behaviour and genetics than simply the lack of experimental data.

The parallels drawn between natural attributes and social behaviour and between the causation of animal and human behaviour are false. Human social behaviour actually reflects our capacity to overcome our biological heritage. Humans are uniquely social beings. This is why human social behaviour cannot be considered in the same terms as natural attributes.

Take the question of the propensity to violence or aggression. In animals, aggression is certainly a natural attribute which can be defined in strict terms and whose parameters can be subject to laboratory or field experiments. For humans, this is not so. The word "aggression", or "violence", is a catch-all which lumps together a variety of different behaviours under a single rubric. The idea that the same set of factors - call them genes, hormones or neuro-transmitters - that led Eric Cantona to karate-kick an abusive fan could also be responsible for atrocities in Bosnia is implausible, to say the least.

Aggression in human beings is not a natural attribute, but is socially created and socially defined. The very term "anti-social behaviour" attests to that. But the norms of social behaviour vary across time and between societies. What is acceptable behaviour in one society or one age is a crime in another. In such circumstances, the idea that crime or anti- social behaviour is determined by our innate nature has no meaning.

The argument that the environment and genetics together determine behaviour also diminishes the social character of human life. Many scientists have toiled to establish what proportion of a particular behaviour is hereditary and what proportion is determined by the environment. But human beings are not the passive sum total of their genetic or environmental influences; our behaviour is shaped by a proportion of one and a percentage of the other. We are active shapers of the world. Unlike animals, humans can act purposively: we make our environment and, in so doing, transform the relationship between biology and the environment.

The relationship between human beings, our environment and our natural attributes is mediated by society. Any scientific investigation that fails to take this into account can have but a poor understanding of human behaviour.