Oliver James: Blame games

Proponents of the genetic view of what makes us different from our siblings had high hopes for the Human Genome Project - it was going to identify the schizophrenia gene, the gay gene and so on.

The first disappointment was when the project found far fewer genes than was expected (around 25,000). This led Craig Venter, the leader of much of the research, to conclude that 'the wonderful diversity of the human species is not hard-wired in our genetic code. Our environments are critical'.

Undeterred by Venter, the genes were further sifted only to find that single ones for mental illnesses simply do not seem to exist. The fall-back position is that there must be dozens, or even hundreds, of combinations of genes responsible. So far this has not been demonstrated and the basis for claims that mental illness has a genetic cause are studies of identical twins.

These have been shown to be highly unreliable (see J Joseph, The Gene Illusion) and indeed, when the molecular geneticists have explored every pathway, it may well turn out twin-study estimates of heritability have been wildly exaggerated. In the case of Attention Deficit Hyperactivity Disorder (ADHD) for example, with hindsight, the over-statements may seem unjustified.

A recent British Journal of Psychiatrypaper began with the claim that ADHD is a 'highly heritable' disorder. However, it went on to reveal that molecular genetics has signally failed to identify genes which explain it, so their claim that it is '60-90 per cent' heritable relies wholly on twin studies. Indeed, America's prestigious National Institute of Health finds no evidence ADHD is a biological brain disorder.

Environmental explanation is to be found in child psychiatrist Sam Timimi's book, Naughty Boys. There are clear links to parental maltreatment (abuse, neglect) but, in addition, environmental biological factors can come into play, like diet or stress. Sons of mothers who are anxious during the third trimester of pregnancy are significantly more likely to have ADHD when followed up at three, five, seven and nine. The anxiety seems to be passed chemically through the placenta to the foetus.

Timimi asserts that there is a myth of genetic-neurological causes of ADHD and that the increased tendency to diagnose it in the past decade coincides with the drug companies' desire to promote lucrative amphetamine-based treatments. The geneticneurological argument became common currency when the pharmaceutical companies sought support for physical treatments. While there is no conspiracy, the doctors and researchers are mostly sided with the view of the companies.

Readers with sons on ADHD medication may dislike hearing all this. But there is now abundant evidence that the drugs have massive side effects and in many cases are just not needed. Timimi describes how using psychological treatments has meant he hardly ever has to employ them and the scientific case for chemical-free treatment grows stronger by the day.

The mental block

The excessive boozing of your undergraduate offspring is not associated with low self-esteem (Psychology of Addictive Behaviours). However, it is predicted if your little soak is a narcissist (me, me, me, I have to be the centre of attention, aren't I wonderful). Protectors against gargantuan ingestion of alcohol were doing well academically and believing in God's love - religious students did not get pissed nearly as much. Implication: Have a God-squadding, self-effacing, swot for a student offspring ...

Similarity in personality has often been claimed as a good predictor of whether couples will stay together. A new study shows that what matters more is whether your partner's personality fits your ideal of what one should be like, rather than whether they actually resemble you (Journal of Personality and Social Psychology). Forty-nine couples were followed for nine months. At the end, the most harmonious both fitted each other's ideal, more than being really similar types of people. Implication: Meeting your dream man is cool, but being his dream girl as well is coolest.

Exposure to male pheromones makes men more likely to feel positively about a product and to regard it as having masculine characteristics (Psychology & Marketing). The same hormones had no effect on women's perceptions.

Implication: If you are male and find yourself in a shop with an unaccountable urge to buy a bra for yourself, insist that they switch off the (hormone-packed) air-con.

Thanks to guardian.co.uk who have provided this article. View the original here.