About 40 per cent of people’s decisions as to whether an economic offer is fair or unfair are governed by genetic influences, scientists have said.

David Cesarini, a Ph.D. student in MIT's Department of Economics, and his colleagues in Sweden recruited twins from the Swedish Twin Registry for their study, published in the Proceedings of the National Academy of Sciences.

The participants were assigned to play an experimental economic game, wherein a proposer makes an offer to a responder on how to divide a sum of money. The offer would be an ultimatum, and if the responder rejected it, none of the two participants would receive anything.

Since rejections in the ultimatum game entailed a zero payoff for both parties, the researchers reckoned that the responder would accept any positive amount, and routinely reject free money in order to punish the proposer for making unfair offers.

As identical twins share the same genes but fraternal twins do not, the researchers were able to detect genetic influences by comparing the similarity with which identical and fraternal twins played the game.

The researchers found that identical twins were more likely to play with the same strategy than fraternal twins.

“Compared to common environmental influences such as upbringing, genetic influences appear to be a much more important source of variation in how people play the game,” Cesarini said.

“This raises the intriguing possibility that many of our preferences and personal economic choices are subject to substantial genetic influence,” said lead author Bjorn Wallace of the Stockholm School of Economics, who conceived of the study.

src: timesofIndia