Thus evolutionary psychology explains human universals, from the claimed preference of men to have sex with younger women to that of women to marry older men, in terms of genetic programmes laid down during an evolutionary past that have built our modular minds to ensure the survival of our selfish genes.
More conventional genetics offers us genes not for such so-called universals but for differences - for violence, alcoholism and criminal behaviour, to say nothing of religiosity and tendency to mid-life divorce. In combination with neurophilosophers, these new breeds see our minds reduced to our brains, and our brains to computational devices. Soon every one of our thoughts and actions, they argue, will be explicable in terms of neural processes.
I regard many of these claims as not merely excessive but unattainable, because they mis-speak the ways that minds and brains work as parts of open systems, as much the products of our personal life histories, culture and social organisation as that of our biology. It is not, of course, that genetics and biochemistry are irrelevant to the workings of mind and brain, but that their causal determinacy is greatly overrated.
It is clear that the reasons for an action offered by neurogeneticists lie deep within the workings of the brain, hormone system and genes. So should I be responsible for any decision to hit someone? Should I be responsible before the law? Should I face one of Jack Straw's new courts? Or should I be incarcerated as an incorrigibly violent psychopath? And what, for that matter, of the person I hit - are his words or actions causing me to hit him not equally a product of brain processes that are immune to the concept of responsibility?
Let's be clear that we aren't that far away from such discussions. The legal status of "not guilty by reason of insanity" - the so called McNaghten rules - is based on a legal fiction which is a neuroscientific nonsense, that there is a clear-cut distinction to make between actions conducted through free will and those conducted involuntarily. I don't mean here the freedom we all have to dine at the Oxo Tower, constrained only by whether we have the money, but the freedom beloved of philosophers and the Judaeo-Christian tradition, in which God gave us all free will.
Already in the US, claims of diminished responsibility by virtue of possessing a gene predisposing towards violence are creeping into the courts. The evidence that possession of such a gene may indeed carry such predispositions is pretty flimsy, based as it is on a single study of a Dutch family in which eight members spread through three generations were all said to show forms of violent activity ranging from murder, through arson and rape, to "having a violent temper". This, of course, is the problem - "aggression" is a portmanteau term. We speak of aggressive surgery or aggressive business executives, in terms of praise; soldiers are supposed to show aggression, though we do not imagine that the Serbian butchers in Kosovo all carry this particular allele. But none the less the legal defence is being attempted in the US. And so, for that matter, is the reciprocal, the so-called Prozac defence, that a violent act was carried out under the influence of a drug legally and medically prescribed. So is the drug responsible, the person who took it, the doctor who prescribed it or the drug company that marketed it?
The increasing strength of neurogenetic knowledge brings new ways of intervening directly and powerfully into brain processes. Tailor-made pharmaceuticals for every conceivable aspect of the human condition, from erectile dysfunction to age-associated memory impairment, generate in their turn a host of newly coined diseases. The tendency to turn social problems into medical conditions - which I call syndromitis - is alive and well, and growing fast.