The Prisoners Dilemma
You and your friend rob a bank and make out like bandits with $10,000,000. Everything is going great, until you’re both caught. The police throw you and your friend into separate interrogation rooms and begin to berate you. They make you an offer you seemingly can’t refuse: rat out your friend in exchange for a lighter sentence. Hey, who hasn’t been there before?
Hopefully not you but if you’ve watched any crime show (real or fake) you’re familiar with the scenario. The premise is a fairly simple one: Two people caught in a pickle, forced to make a decision that results in the best outcome for themselves. The question is: which decision is in the individual’s best interest?
On one hand, you can tell the cops how your friend was behind everything in hopes that they only send you to jail for a few months instead of a few years. On the other hand, you can play it cool and give them nothing. It sounds pretty simple, if you rat them out then how does that not help you? Well, what’s going on in the other room? The cops are giving your friend the same offer. So what happens if you both rat each other out? What happens if you both play it cool? What happens if you play it cool and your friend rats you out? What happens if you rat your friend out who plays it cool? This is a classic “Prisoners Dilemma“.
Four possible outcomes with varying degrees of benefit for the individuals involved.
| Person 2 cooperates | Person 2 betrays | |
| Person 1 cooperates | Most mutual benefit | Person 1 Loses |
| Person 1 betrays | Person 2 loses | Worst mutual outcome |
Human Nature of the Prisoners Dilemma
With all of this knowledge it seems easy to figure out what is best to do. But when individuals don’t know how their decision will impact the end result, human nature fails us. In fact, a recent study indicates that when presented with this general scenario (and it can be applied to literally anything, it does not always have to involve the law) humans only chose to cooperate 40% of the time. This means that more than half the time the decisions made by the individual hurts the group.
The Bachelor Pad
ABC managed to produce a surprisingly riveting finale to what can only be described as a vastly interesting commentary on human nature in The Bachelor Pad. For those that don’t already know, the series threw a group of single men and women into a house together and let them live. In essence, that was the show, with the exception that based on nothing at all (such as an academic or athletic competition), each week a man and a woman was voted off the show by their gender counterparts. It became advantageous for the individuals to align themselves with someone of the opposite sex so that person could fight for them at the end of each show in trying to get their peers to not vote their mate off the show. At the end of the tunnel? $250,000 to the last one standing.
The final two (which was designed to be a man and a woman, and therefore a couple) were voted into position by the peers (the cast of the show) but only one could win the prize, so they thought.
The final two contestants Natalie and Dave, learned that the strength of their relationship would ultimately determine who won the money. They were presented with a classic “prisoners dilemma” and sent into separate rooms to make their final decision.
| Natalie shares with Dave | Natalie keeps it all | |
| Dave shares with Natalie | Both take home $125,000 | Natalie takes home $250,000 |
| Dave keeps it all | Dave takes home $250,000 | Dave and Natalie take home nothing |
In the end both decided to share the money, in contrast to typical human behavior. One flaw in the design of ABC’s ending was that the contestants knew the outcome, often not the case in a typical prisoners dilemma. Furthermore, it is possible that the two did in fact have a relationship that helped guide their decision, or perhaps they merely fell under the 40% of humans who chose to cooperate. In any case, they both walked away with a cool $125,000
A final interesting caviet to the human nature of the Prisoner’s Dilemma
The setup of The Bachelor Pad’s Prisoners Dilemma was unique in that the contestants were privy to the ramifications of the wrong decision. As previously mentioned, this often isn’t how the Dilemma is designed, which helps fuel the natural human tendency for greed. Ultimately, whatever an individuals decision in such a scenario, it is based purely on greed: The best possible outcome for me.
We know that 60% of humans will make chose to not cooperate with their partner, thus 60% of the time they both lose. But what happens if you individuals to replay the dilemma over and over but not specifically tell them how they can win? This can be setup in a game that rewards each player with points for their decision and playing the game an unknown or random number of times. What we discover in such scenarios is that humans learn to work together to maximize their points.
The silver lining in the human nature of the Prisoner’s Dilemma
The ultimate goal in these scenarios is always driven by greed. The Dilemma is set up to work on that greed so that each individual loses. The proof of this comes from the study of the topic: More often than not, individuals do not chose to cooperate with their counterpart because on the surface it seems the most likely way to win. Since the odds are that each individual will not cooperate, the most common outcome is that both individuals lose. Thus, human nature (greed) is used against the individual so that they inevitably fail.
The silver lining in this though is that humans can learn through experience. Typically, with enough experience, both individuals learn to work together to maximize their gains.
This basic concept is known as the Nash Equilibrium, named after John Nash, the mathematician made famous (to non-math nerds) by the biographical movie A Beautiful Mind (depicting the schizophrenic academic’s life).
In short, an individual or entity (such as a nation, or business) can maximize returns (monetary or otherwise) by making the best decision for thyself but accounting for the decision of thy counterpart.
Most likely what happened on last night’s Bacheler Pad was that Natalie and Dave, being privy to the likelihood that they could walk away with nothing after otherwise winning the game, accounted for each others decision and ultimately chose wisely by sharing the money so that they each won.
As much as it pains LaymanPsych to say this, ABC managed to create a fascinating, albeit somewhat trashy, case study of human nature. And that is that.
More Reading
Preference, Belief, and Similarity: Selected Writings
Play out the prisoner dilemma with the computer