Definition of Prisoners Dilemma

What is the "prisoner's dilemma"? What is the definition of the term "prisoner's dilemma"?

The "prisoner's dilemma" is a fascinating study of game theory and an example of a situation where the rational choice is not always the choice that is made.

The illustration of the term Prisoners Dilemma.

Let's take the standard "prisoner's dilemma" example that was framed by Merrill Flood and Melvin Dresher in 1950.

Two members of the same gang are arrested.

The prosecutors have enough evidence to sentence both members on a lesser charge, though they are hoping that a confession from one or both of the men will result in a greater charge.

The prosecutors offer both men the same deal. If you rat out the other member, you earn the possibility of serving no time in jail, provided that the other member stays silent.

If both gang members rat each other out, they will both serve two years in jail.

If one gang members rats the other out and the other stays silent, the collaborating gang member will go free, while the silent gang member will serve three years in jail.

If both gang members stay silent, both members will serve one year in jail on the lesser charge.

This is the "prisoner's dilemma" - do you stay silent or rat out your partner?

The correct choice, in terms of individual reward, is to rat out your partner, as there is a greater potential reward compared to staying silent.

Humans, however, tend to exhibit a bias towards co-operative behavior.

In another real world example, two athletes are given the opportunity to take steroids.

If neither athlete decides to take steroids, neither athlete gains an advantage over the other.

If one athlete decides to take steroids, they will gain an advantage over the other athlete and potentially make more money. There are obvious downside risks though, in the form of potential legal and health ramifications.

If both athletes decide to take steroids, neither athlete gains an advantage, though both athletes get all of the potential downside risk.

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