This is partly because evolutionary research nearly always upholds the right-wing world view adhered to by 90 per cent of the press. A new study claiming a "gene for" depression or being gay is far more likely to attract column inches or television documentary coverage than one indicating a major causal influence of class, gender bias or parental care on our psychology.
A fine example is a social psychological text published earlier this year, Wednesday's Child by Antonia Bifulco and Patricia Moran (Routledge). Thus far, the sole attention it has attracted is one brief news report in this newspaper.
Complete with accessible case histories, the book describes the results of four studies that have been undertaken over the last 30 years of the social origins of depression in women, funded by the Medical Research Council at Royal Holloway and Bedford New College, London University.
Previous publications from the same research unit have provided by far the most influential and important demonstration of the causes of depression, evidence of infinitely greater significance than anything produced by geneticists before or since: in a sample of 458 women, those with a low income (23 per cent) were far more likely to be depressed than those with a high income (6 per cent) - a finding that has been replicated in nine further studies world-wide.
To a jaded media executive the fact that being poor puts women at much greater risk of depression is of almost no interest. But Wednesday's Child moves the story on to a new level by explaining why some low-income women become depressed, but not others; the reason is quality of care during childhood.
Bifulco and her colleagues interviewed 500 women about whether they had been neglected or abused as children. One third of those who had suffered one of these childhood adversities had been depressed in the 12 months before being interviewed, compared with only 12 per cent of women who had suffered no childhood problem. Equally striking, of the women who had suffered all these forms of childhood adversity together (neglect, sexual or other physical abuse), one half had been depressed in the last year.
To separate the direct impact of childhood adversity from other influences, Bifulco examined the effects of four other factors that are known to be important: loss of a parent before the age of 16, parental conflict, parental psychiatric problems, and poverty.
As in previous studies, all these were strongly associated with depression in the adult women. However, this association was found only when coupled with neglect or abuse. If you had lost a parent, for example, or had disharmonious, poor or psychiatrically disturbed parents, it made you more likely to be depressed in adulthood only if you had also been abused or neglected. This research poses a major challenge to the genetic triumphalism that has swept our media.
Try reanalysing Bifulco's findings from the widely held assumption that depression is substantially caused by genetic factors. First of all, if depression is four times more common among poor women than in rich women does that mean that the poor have much more "depressing" genes? There is not a scrap of evidence to support the idea, although it is theoretically possible.
Even if genes explain why the poor are more depressed, how come women who are neglected or abused are so much more likely to be depressed than those who are not? Surely, these are purely environmental experiences which have nothing to do with a girl's genetic make-up.
The genetic retort is that, yes, the neglect and abuse are environmental but perhaps the propensity to inflict them on children is genetic - that parents are born with genes that make them into neglectful or abusive parents. There is a small amount of evidence that parenting styles may be slightly influenced by genes but, taken overall, Bifulco's new book makes genetic explanations of depression seem a very long shot.
Far more likely is that genes play a negligible role in much depression and that being abused and neglected as a child is depressing. Being poor - not bad genes - makes stressed-out parents more likely to be abusive and neglectful. This environmental explanation has the added practical attraction of suggesting that if we reduced the proportion of people being raised in poor and abusive or neglectful homes, the amount of adult depression would consequently decline.
Sadly, despite the potential significance of Bifulco's discoveries, they have attracted just one small newspaper report. Unlike, for example, the American evolutionary psychologist Steven Pinker, author of How The Mind Works, whose contribution to our understanding of human psychology is tiny by comparison, there have been no in-depth interviews with Bifulco and no lengthy articles commissioned from her.
Oliver James's `Britain on the Couch - Why We're Unhappier Compared With 1950 Despite Being Richer' is now available in paperback (Arrow, pounds 7.99)Reuse content