Gener styr syn på orättvisa

Inom spelteorin finns ett känt spel som kallas ultimatumspelet:

”The ultimatum game is an experimental economics game in which two players interact to decide how to divide a sum of money that is given to them. The first player proposes how to divide the sum between themselves, and the second player can either accept or reject this proposal. If the second player rejects, neither player receives anything. If the second player accepts, the money is split according to the proposal. The game is played only once, and anonymously, so that reciprocation is not an issue.”

Diverse experiment har visat att andraspelaren mycket ofta tackar nej till låga bud, trots att det innebär att hon tackar nej till pengar. Det kan tolkas som att hon är villig att betala för att bestraffa en gniden förstaspelare, som ger ett i hennes tycke orättvist erbjudande

En studie från 2007 visar att denna tendens att avvisa alltför låga bud i hög grad förefaller genetiskt bestämd. Abstract:

”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.”

En möjlig implikation skulle kunna vara att vår uppfattning om vad som är orättvist mer allmänt har evolutionära rötter. Det kan i sin tur antyda att vi bör kunna ifrågasätta denna uppfattning, i den mån vi inser att den uppkom i en kontext som skiljer sig från den vi lever i idag (i linje med vad F. A. Hayek föreslår i ”The Atavism of Social Justice”).