“We can model many situations using what is called game theory…”
Shutterstock/Ann Kosolapova
It’s a dog-eat-dog world. Every man for himself, no matter the cost. If so, how could behavior such as cooperation emerge?
From evolutionary biology to international diplomacy, we can model many situations using something called game theory. These games feature actions or strategies available to each participant, as well as payoffs, which are positive or negative values that each player gains or loses with each outcome. Some games are “zero-sum”, in which one player’s gain is equal to another’s loss. Some are not.
A famous (and not zero-sum) game is particularly revealing here. The Prisoner’s Dilemma, in its primary form, imagines two “criminals” who have been arrested and held in separate cells with no way of communicating.
There is not enough evidence to convict either of the main charges, but enough to convict both on a lesser charge. Both are offered a deal simultaneously: testify that the other committed the more serious crime and be released while the other receives three years in prison. But there is a trap: if they both betray each other, they each spend two years in prison. If both remain silent, each gets a year for the minor charge.
Each player’s winnings can be shown as the number of years he serves in prison. If both remain silent, the payoff for each is -1. If player A betrays player B, A gets 0 and B gets -3. Betray yourself, and A and B get -2 each. How can a player maximize his winnings?
Sometimes each player has a strategy that is the best response to whatever the other player does. This is called the Nash equilibrium: everyone does what is best for themselves and gets the best possible outcome.
The dilemma is how the actions interact if they don’t know what the other will do. Imagine that you anticipate silence. If your opponent feels the same way, you will get a better payoff by betraying. If the opponent plans to betray, you get a better result by betraying as well. Either way, your best action is to betray. This is true for both players, so each betrays, with a combined payoff of -4.
If both players trust each other and remain silent, the combined payoff is -2. The fact that dog eat dog leads to a worse outcome than cooperation suggests how the latter could emerge.
In a famous experiment from the 1980s, 62 computer programs played 200 rounds of the prisoner’s dilemma. Importantly, they could make moves based on an opponent’s actions in previous turns. Selfish strategies tend to fare worse than altruistic strategies. Successful strategies did not betray first, but did so when an opponent had betrayed in a previous game. They were also forgiving, returning to silence when an opponent stopped betraying.
So even if “pure” game theory leads to a bad outcome, a little kindness can overcome this problem. Be kind, but don’t let anyone take advantage of you. You have game theory to back you up.
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