Learn to play well with other people.

It’s a world where dogs eat dogs. Each to their own, regardless of the cost. If so, how could behavior like cooperation ever arise?

From evolutionary biology to international diplomacy, we can model many situations using so-called game theory. These games have 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 result. Some games are “zero-sum” games, where one player’s gain is equal to another’s loss. Some are not.

A famous (non-zero-sum) game is especially revealing here. The prisoner’s dilemma, in its primary form, imagines two “criminals” who have been captured and kept in separate cells with no way to communicate.

There is not enough evidence to convict on either of the main charges, but there is enough to convict both on a lesser charge. The two are offered a deal simultaneously: testify that the other committed the felony and walk free while the other receives three years in prison. But there is a problem: if they both betray each other, they will each spend two years in prison. If both remain silent, each will receive one year for the lesser charge.

Each player’s payoffs can be shown as the number of years he or she 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. They betray each other and A and B each get -2. How can a player maximize payout?

Sometimes each player has a strategy that is the best response to whatever the other player does. This is called a Nash equilibrium: both do what is best for them and both get the best outcome.

The dilemma is how actions interact if you don’t know what the other will do. Imagine that you plan silence. If your opponent feels the same way, you’ll get a better reward if you betray them. If the opponent plans to betray you, you will get a better result if you betray too. 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 gives an idea of ​​how the latter might arise.

in a famous 80s experiment62 computer programs played 200 rounds of the prisoner’s dilemma. Crucially, they could make moves based on an opponent’s actions in previous rounds. Egoistic strategies tended to have worse results compared to altruistic ones. Successful strategies did not betray first, but rather did so when an opponent had betrayed in a previous game. They were also forgiving and fell silent again when an opponent stopped betraying them.

So while “pure” game theory leads to a bad outcome, a little kindness can overcome it. Be kind, but don’t let anyone take advantage of you. You have game theory to back you up.

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