Imagine that your boss wants you to work, but you'd rather watch cat videos. Your best strategy is to learn your boss's patterns so that you'll appear hard at work only when she's watching. New research shows that chimpanzees are better than humans at making this kind of Machiavellian deduction.

Caltech behavioral economist Colin Camerer wanted to understand the evolution of optimal decision-making. Working with a team including Kyoto University's Tetsuro Matsuzawa and PhD student Christopher Flynn Martin, he designed a game that he taught to six chimpanzees from Kyoto University Primate Research Institute. The "Inspection Game" is no more complicated than hide-and-seek. Two chimpanzees sit back to back, each with a computerized touch screen in front of him or her. Two blue boxes appear on the left and right sides of the screen. Each chimpanzee simply has to choose one of them, but the two chimps have different jobs. One of them is the "hider" – he wins if he chooses the opposite of his partner's choice. The other is the "matcher" – she wins if she chooses the same as her partner.

Let's say Ayumu is the hider and Ai is the seeker. Ayumu wins if he chooses "right," but his mom chooses "left" (or vice versa), while Ai wins whenever she and her son pick the same side. Each pair played 200 rounds, and winners received chunks of apple for their efforts.

One way to go about the game is to play randomly, but that isn't a particularly fruitful strategy. Not if your goal is to get as many pieces of apple as possible. Instead, the chimpanzees should try to accurately predict what their partners will do next, and play the game accordingly, without being too predictable themselves.

That's essentially the same as in the scenario I asked you to imagine above. Your goal should be to anticipate your boss's behavior, so that you can anticipate when she'll be watching you work and when you can get away with watching cat videos. At the same time, your boss needs to anticipate your strategy, perhaps by becoming more unpredictable.

Still, if both players behave most strategically, game theory predicts that there's a limit to how often either player can win, and it's called the "Nash equilibrium," named for mathematician John Nash Jr., who won the 1994 Nobel Memorial Prize in Economics.

#### Chimpanzees Rule Game Theory

In experiment after experiment, no matter the particular details of the game being played, humans tend to deviate widely from the Nash equilibrium, suggesting that there's something about human reasoning that prevents us from constantly making the most strategic decisions. That's why Camerer and his colleagues were so surprised by the performance of the chimpanzees in the Inspection Game. They performed almost at the Nash equilibrium!

Even when the researchers tried to confuse the chimpanzees by changing the reward distributions, or by arbitrarily switching who was the "hider" and who was the "seeker," the chimpanzees rapidly adjusted, maintaining their play at the most optimal of levels.