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The dark side of fair play

We often think of playing fair as an altruistic behavior. We’re sac­ri­ficing our own potential gain to give others what they deserve. What could be more selfless than that? But new research from Northeastern Uni­ver­sity assistant professor of phi­los­ophy Rory Smead suggests another, darker origin behind the kindly act of fairness.

Smead studies spite. It’s a conundrum that evo­lu­tionary biol­o­gists and behavioral philosophers have been mulling over for decades, and it’s still rel­a­tively unclear why the seemingly pointless behavior sticks around. Tech­ni­cally speaking, spite is char­ac­ter­ized as paying a cost to harm another. It yields vir­tu­ally no pos­i­tive outcome for the per­pe­trator. So why would evolution—which is supposed to weed out such behaviors—let spite stick around?

Smead’s research, conducted in col­lab­o­ra­tion with Patrick Forber of Tufts Uni­ver­sity and recently published in the journal Pro­ceed­ings of the Royal Society B, sheds new light on this nefarious phenomenon.

A common means of studying social behaviors is through sim­pli­fied models and games. One of these is called the ultimatum game, in which a one player proposes a division of resources the other player can either accept or reject. Suppose each inter­ac­tion concerns the dis­tri­b­u­tion of 10 one-​​dollar bills. The first player could suggest that he take $5 for himself and give the remaining $5 to the second player. That would be a fair play.

However, that first player could also go for an unfair option in which he keeps $9 for himself and gives just $1 to the second player. While the second player is worse off if he rejects the proposal (he’s got ziltch in his pocket instead of $1), he almost always does so in real-​​world versions of the game: It’s just not fair.

But when Smead and his colleagues decided to sim­u­late this game math­e­mat­i­cally to see how it would play out, they found that in fact the exact opposite happens. Fairness usually gets flushed out of the system since it’s more ben­e­fi­cial for both the first player (the proposer) to suggest unfair offers and for the second player (the responder) to accept them.

“Evo­lu­tionary models don’t match what we’re observing in real life,” Smead said. Clearly, he thought, there must be something else going on.

In the new study, Smead and Forber con­sid­ered that the ultimatum game is actually quite unlike the real world. It’s an extremely sim­pli­fied sim­u­la­tion of one of infinite ways that two indi­vid­uals could act. The researchers couldn’t, for obvious reasons, make the game as complex and nuanced as real world social inter­ac­tions, but they could instead just add a little more nuance to it and see what happened.

So that’s what they did. In their new version of the game, the researchers introduced something called “neg­a­tive assortment.” Think of assortment as the like­li­hood that a person you’re interacting with is similar to you. In neg­a­tive assortment, that like­li­hood is low, so in the ultimatum game the players would likely use different strategies.

Here’s where spite comes back into play. If you and I both commit to just making fair offers, but my strategy is to accept all offers—be they fair or unfair—and yours is to accept only fair ones, we are different. A spiteful strategy would be to both make only unfair offers, but reject such offers when they come from the other person.

In the orig­inal ver­sion of the ulti­matum game, a spiteful player will usu­ally walk away with nothing and for­feit the game. But with neg­a­tive assort­ment, spite becomes common and actu­ally ends up pro­moting fair­ness. “Acting fairly protects you from spite,” Smead explained.

Think of it this way. A “gamesman” is someone who only makes unfair offers to ben­efit him­self but accepts what­ever comes his way because he believes it’ll all wash out in the end. “Gamesmen become a target for spite because they’re making unfair offers,” Smead said. The “spiters” will reject those offers, even­tu­ally killing off the gamesmen.

But fair players will now do quite well in the pres­ence of spite. Since they don’t make unfair offers, they don’t risk being rejected by the spiteful players. Fairness actually becomes a strategy for survival in this land of spite.

“Real social life is com­pli­cated,” Smead said. While his new version of the ultimatum game is still a sim­pli­fi­ca­tion, it illuminates another possible expla­na­tion for fair behavior that hadn’t been con­sid­ered before.

– By Angela Herring



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