Wednesday, February 04, 2009

Beauty is the eye of the ...group?

Science Now ran a very interesting story this week that I heard on the Science Podcast. It is based on an article that appeared this month in Neuron.

The researchers asked 21 young women to rate the attractiveness of 222 female faces while lying in an fMRI scanner. To avoid any confounding effects of race or sexual desire, all the test subjects and faces were white, and all the subjects were heterosexual. The volunteers saw each face for about 2 seconds and assigned it a score from 1 (least attractive) to 8 (most attractive). They were then told how another group of women had rated the face. These "group ratings" were actually generated by a computer that gave each face a different rating than the test subjects about two-thirds of the time. As the researchers suspected, the rostral cingulate zone and nucleus accumbens [areas of the brain believed to be part of that learning system]  fired up when the group ratings did not match the subject's score. Moreover, brain areas associated with reward were less active when a subject’s predictions deviated from the group's score...

What does this imply? It seems that when the group disagrees with us we modify our beliefs, which is what social learning would imply.  I think economists would be comfortable in fitting this into a framework like the "herding" or "informational cascade" models where we update our beliefs based on the revealed beliefs of others. But there also seems to be a direct "utility" (reward) we get from agreeing with others.  This seems like a pure payoff to conformity. The question is why would evolution instill both mechanisms?  Perhaps conformity is just a good strategy most of the time. So instead of learning from others we have some tendency to just mindlessly copy them. But it suggests that someone with social disorder might indeed be more creative because maybe they don't feel that disutility from having divergent beliefs. This would in turn create benefits for the conformers because every now and then the non-conformist comes up with something so demonstrably better that some of the conformists start doing it despite the psychic penalty from deviating. Can there be an equilibrium where the majority have conformist tendencies but a small minority do not?