Thursday, January 25, 2007

Altruism and evolutionary psychology

BBC’s NewsNight yesterday (Jan 24th 07) had a quirky feature about heroism. The item featured a guy who had rescued a child and her mother from a burning car, which promptly exploded a few seconds later. He was lucky to have survived.

In the style of news programmes these days, under his name banner across the screen was the role the programme had allocated him. It was the one word: ‘Hero’.

I cringed.

The presenter then raised the question as to why the hero had risked his life in this way. The mother and child were unrelated to him - no genetic advantage seemed to be involved. This was posed to the pundit, a ‘professor in evolutionary biology’ from Imperial College.

The professor gave his opinion that altruism was a ‘mistake’. Brain circuitry which was meant to help closely-related kin had been ‘hijacked’ by these individuals.

I cringed again.

I’ve seen this reductionist argument over and over. It cannot be right. A kin-based altruism which kept making mistakes would have been powerfully-selected against. There is a much better explanation based on the fact that we can’t easily recognise kin.

The same textbooks which have a problem with altruism often observe that children brought up together from a young age observe the incest taboo - they do not form sexual associations, even if genetically unrelated. Why is this relevant? Because we do not have inbuilt DNA-testers, we cannot easily determine our degree of social relatedness to others. We use social-proximity cues to proxy for (close or not-so-close) kin-relatedness.

Most analysts concur that our ‘environment of evolutionary adaptedness’ was an extended kin-group of up to 120 members. In such a group, a random pair of individuals have relatively low genetic overlap and certainly cannot determine the degree of relatedness by observation: the basis of altruism is therefore Trivers’ reciprocal altruism (but based on kin-group selection) as we shall now examine.

Psychologically we have strong emotional drives to identify with a group, and such identification produces a constellation of ‘loyal’ behaviours including altruistic heroism. In a harsh world, the extended kin-group could not cohere and survive without strong loyalties.

if we stir into the mix:
  1. kin-groups;
  2. strong selection pressure for kin-groups expressing in-group loyalty against those with weak social ties;
  3. the learned nature of who is in the group;
we have a perfectly acceptable theory of heroism which makes it strongly selected for, not a ‘mistake’.

There, how hard was that?

PS. OK, I concede that maybe that was what the professor really meant: it's hard to make any kind of argument when you're restricted to 45 seconds. Still, it came across as stupid. Sorry!