Chimps beat humans at game theory

In Chimpanzee choice rates in competitive games match equilibrium game theory predictions, a paper in Nature by Colin Camerer and colleagues, researchers document the astounding performance of chimpanzees in classic game-theory experiments -- a performance that's substantially superior to humans who play the same games:

Camerer had chimps play versions of the matching pennies game also called the cat and mouse game. In the cat and mouse game each player can go left or go right. The cat wins when cat and mouse choose the same strategy. The mouse wins when they choose different strategies. In the simple version the best strategy is 50:50, toss a coin. When the payoffs change, however, the optimal strategies still involve randomization but they change in surprising and nonobvious ways.

Chimps play the cat and mouse game very well. First, the chimps converge on the Nash Equilibrium strategies. In one set of games the Nash equilibrium strategies had randomization frequencies of .5, .75 and .8 and the chimps played .5, .73 and .79. Second, when payoffs change the chimps adapt their strategies very quickly simply by observation of outcomes.

Chimps Rock at Game Theory [Alex Tabarrok/Marginal Revolution]

(via Kottke)