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The Prisoners' Dilemma
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True or false? For those who are playing The prisoners' dilemma repeatedly, it is random that decides the winner.
Here are Bob and Diana in their cells. They committed a crime, and agreed on one thing before they got caught. They will not tell the police anything. Now, in prison, they can no longer talk to each other. Bob is thinking.
A good thing Diana and I promised not to say anything. Since we’re cooperating and keeping quiet, we’ll probably get a year each in jail, but we’ll soon be out again. But What if Diana betrays me, and blames everything on me? Then my punishment will be longer. Five years?
And she would be released, while I’m rotting in here. Yes, of course she’ll betray me. That’s not good. What should I do? What if I blame everything on her instead?
We’ll probably get a bit longer time in prison than if we cooperate, two years each. That’s a long time, but at least I won’t have to do five years. I have to betray her too. And if she actually does cooperate and keeps quiet, while I betray her, then I will be released at once! And she’ll get five years.
That would be the best thing for me. Bob has reckoned that if Diana cooperates with him then it’s better for Bob to betray. 0 years is better than 1. And if Diana betrays, then it’s a lot better for him to betray too. 2 years is better than 5.
Whatever Diana chooses, it is always better for Bob to betray her. Diana thinks exactly the same way. So, both of them betray, and they get two years each in prison. What if they had both been quiet, cooperated? If they had kept their promises?
They would have got only one year each in jail, instead of what now happened, two years each. It would have been better for them both. But they both acted selfishly and the result was worse than if they had also taken care of each other. This problem is called The Prisoners’ Dilemma. Let’s make it into a game.
You will play it. You can choose from the buttons “Cooperation” and “Deceit”. Your opponent has the same choice. Two buttons, “cooperation” or “deceit”. It’s the same pattern as for Bob and Diana in their cells.
The objective is to get as short a time in prison as possible. Bob and Diana figured out that the safest option was to choose “deceit”. At least when you play only once. But if you play many times, over and over again, then, how do you minimise the time in prison? Scientists have examined this many times and eventually they found the best strategy.
It has three simple rules: 1. Start with cooperation. 2. If your opponent betrays you, it must not go unpunished. Get even, betray, in the next round.
3. Be forgiving. You get back for the deceit once, but then you forgive, and choose cooperation again. Cooperate, retaliate if someone betrays, but then forgive. Does that remind you of something?
Or someone? Are you thinking perhaps of yourself? Of humankind? We like gathering together and being helpful. If someone betrays us, the first impulse is often to get even, but we are also ready to forgive, since company and cooperation are things we enjoy.
Most human beings are like that. The game Prisoners’ Dilemma shows that it might be beneficial for an individual in the long run to cooperate, even when in the short run it is better for the individuals to look after themselves. Cooperation is not only good for you, but also for the people around you.