TRAGEDY

Nothing could be worse than losing a child who has died in her twenties, after a career of alcoholism and drug-taking documented in prurient detail by the tabloids. But the suffering endured by Amy Winehouse's parents must be made worse by the judging voices echoing in the aching emptiness she will have left behind. The sheer number of explanations of the addiction that accompanied her journey from a brilliantly successful artist to a tragic figure betrays the poverty of our understanding.

Given the increasing fashion for seeking biological bases for human behaviour, it is not surprising that genetic explanations for addiction have been sought. It is true that the children of addicts may be more likely to become addicts themselves; and comparisons of genetically similar twins brought up either together or apart suggest that environmental influences do not entirely account for this association. But the evidence of a hereditary contribution to addictive behaviours falls far short of that sufficient to support the kind of genetic fatalism made popular by Émile Zola when he explored the doomed Rougon-Macquart family in a mighty cycle of novels.

Just how remote some biological approaches are from human life is betrayed by the fact that one of the favourite animal models for studying alcoholism is the fruit fly. Like us, they lose postural control and sexual inhibition when they are exposed to alcohol.