Finding these genes will immediately raise the question of what society or individuals should do with the knowledge. My view is that, far from being afraid to find the truth in this area, society should be prepared to act upon it, even though economic, educational and other forms of inequality are the biggest barrier to most people realising their potential. For if genes do account for about 50 per cent of the variability in IQ scores, and if we believe that general cognitive ability is useful in life, then manipulating genes or their effects to increase IQ should be investigated. Plomin agrees that in principle this is possible, but points to practical difficulties and emphasises his aim of 'preventing IQ from being lowered rather than being heightened'. To understand intelligence', Plomin told me, 'we will need to detect many genes, each of which accounts for less than one per cent of the variability'.
Current techniques can only detect gene effects of five per cent or more.
Plomin's caveats are well made. But he is being a little naive. It seems clear that, in time, it will be possible to use the current research to mount a pharmacological intervention if we choose to. Unless scientists like Plomin are prepared to face up to this, and defend it if they think it is in principle a good idea, they will find it hard to win support for their work. He would like to believe that the ethical angst is a storm in a teacup produced by 'incredibly condescending' reporters who see themselves as 'protecting the public' against genetic determinism.