Tuesday, October 02, 2007

Heritability of the Ultimatum Game   posted by Razib @ 10/02/2007 11:12:00 AM

Finally, behavioral economics & human variation! Heritability of ultimatum game responder behavior:
Experimental evidence suggests that many people are willing to deviate from materially maximizing strategies to punish unfair behavior. Even though little is known about the origins of such fairness preferences, it has been suggested that they have deep evolutionary roots and that they are crucial for maintaining and understanding cooperation among non-kin. Here we report the results of an ultimatum game, played for real monetary stakes, using twins recruited from the population-based Swedish Twin Registry as our subject pool. Employing standard structural equation modeling techniques, we estimate that > 40% of the variation in subjects' rejection behavior is explained by additive genetic effects. Our estimates also suggest a very modest role for common environment as a source of phenotypic variation. Based on these findings, we argue that any attempt to explain observed ultimatum bargaining game behavior that ignores this genetic influence is incomplete.

That means that 40% of the variation in response to the Ultimatum Game is due to variation in genes. Yes, I know the Ultimatum Game is pretty bizarre. And I know there might be all sorts of complexities. But it's a start!

(and it's Open Access)