Games Species Play

On the day James Watson and Francis Crick discovered the structure of DNA, Crick was heard to remark that they had "found the secret of life." With all due respect for DNA, I would like to nominate another candidate for secret of life: non-zero-sumness. An ugly word, I know, but remember: deoxyribonucleic acid didn't get where it is today on the basis of its looks.

Alas, unlike Francis Crick, I can't claim to have discovered the secret I'm touting. It was discovered half a century ago by the founders of game theory, John von Neumann and Oskar Morgenstern. They made a distinction between zero-sum games and non-zero-sum games. In zero-sum games, the fortunes of the players are inversely related. In tennis, in chess, in boxing, one contestant's gain is the other's loss. In non-zero-sum games, one player's gain needn't be bad news for the other(s).

Indeed, in highly non-zero-sum games the players' interests overlap entirely. In 1970, when three Apollo 13 astronauts were trying to get their stranded spaceship back to Earth, the outcome would be either equally good for all of them or equally bad. (It was equally good.)

Since game theory was born, it has found ever broader application. Genes, for example, can be viewed as players. The handful of genes in a primordial one-celled organism were in roughly the position of the Apollo astronauts. They were in the same boat--a dinky bloblike boat--and so faced an ultimatum: cooperate to sustain your vehicle or die.

The genes didn't think about this logic, of course. But since genes that didn't comply with it--didn't interact constructively--were dumped by natural selection, life came to be filled with teams of genes that played non-zero-sum games well. Larger and larger teams of genes played more and more elaborate games. In other words, more complex life forms evolved, notably including Homo sapiens. Basically, you are a large and well-played non-zero-sum game. Congratulations!

Some animals, besides being non-zero-sum games, are good at playing them. Vampire bats returning from a successful blood-sucking expedition share the proceeds with bat buddies that had a tougher night on the parasitism front. Since these magnanimous bats will someday be needy themselves, this reciprocal altruism is a win-win game. Natural selection favored animals good at win-win gamesmanship.

No other animal plays non-zero-sum games as tirelessly as we do. Much of your emotional life is natural selection's way of getting you to play. Gratitude for favors rendered and guilt over neglecting a friend help you start or sustain potentially win-win games.

The words on this page--indeed, words, period--are a product of non-zero-sumness. The game theorist Thomas Schelling has noted that in a purely zero-sum game there is no rational reason to communicate. If you see opposing coaches talking before a football game, they are probably talking about some realm where their interests overlap--swapping gossip, maybe, or rescheduling a game to avoid injuries in bad weather. But neither coach has cause to communicate honestly about the game.