Friday, January 25, 2013

Genes and behavior

Matt Ridley referred recently to some new research on a population of free-living monkeys (macaques) which claims to show that individuals having a specific version of two genes tended to be less social.

But, as Ridley points out, there is nothing very surprising here, as studies of human twins have previously found evidence of genetic heritability with respect to sociability and related traits similar to that reported in the monkeys.

'The mutations making monkeys less social,' Ridley explains, 'have been tied to anxiety and a tendency to avoid risks. This may explain why they persist. Although well-connected monkeys generally have more offspring, anxious monkeys may be more vigilant to threats.'

It may not be drawing too long a bow to see here an embryonic simian parallel to the conservative/liberal divide, as traits like anxiety and risk aversion are normally associated with a conservative tendency.

The weight of research evidence has gradually muted the protests that this sort of research (linking genes and behavior) used to inflame.

Ridley alludes, for example, to the controversies sparked by the pioneering work of Seymour Benzer, who set out in the 1960s to find mutations in fruit flies that affected behavior. [On a slightly different tack, Benzer's mother was quoted as asking skeptically: 'From this, you can make a living?']

Benzer 'was soon able to identify mutations related to hyperexcitability, learning, homosexuality and unusual circadian rhythms, like his own: Benzer was almost wholly nocturnal.'

Ridley is not a genetic determinist, however. 'A discovery that genes affect behavior is no more or less deterministic than a discovery that family or education does so. Whether you are anti-social because your mother was unemotional – a fashionable theory in the 1960s – or because of a mutation tells you nothing about whether your condition can be remedied by some intervention.'

This is the crucial point: the extent to which these tendencies are amenable to change. Individual variation complicates the picture of course: some of us, no doubt, are more nocturnal or whatever than others.

But I daresay future research will lead, not only to detailed knowledge of particular gene-behavior linkages and potential intervention techniques, but also to a more satisfactory general understanding of the potential for reconfiguring our brains than we have at present.

Which is not to say that we should be too ready to intervene, even where it is possible; but, clearly, where it proves not to be possible – or not to be practicable – it makes sense to embrace our natural tendencies and integrate them as best we can into a broad social vision and way of life.