Home > philosophy > Prisoner’s Dilemma

Prisoner’s Dilemma

There are some remarkably simple thought experiments which we can perform to reveal surprisingly subtle and deep truths about the nature of reality and how the universe really works. There are many of these in the history of science and some of the most famous were those used by Einstein to clarify his ideas on relativity, but in this blog post I want to concentrate on some more related to social sciences.

I initially got the idea to write this entry after listening to a an episode of the excellent BBC Radio 4 podcast “In Our Time” on the subject of Game Theory. Of course I already knew a bit about the subject but this just reminded me how cool it really is.

Most people have heard of the game “rock paper scissors”. This is a game for two people who simultaneously reveal their hand shaped like one of those objects. Each object can defeat another object or be defeated by another object. For example paper defeats rock by covering it but is defeated by scissors which cut it.

So what is the best strategy to win that game? Assuming your opposition also knows the best strategy there is no way to win in the long term (but you can draw). And the best strategy is to present one of the three shapes randomly. That’s a trivial example so let’s move on.

Imagine you and an accomplice are arrested by the police and offered a deal (because the police have no strong evidence against you). If you confess and your accomplice doesn’t you go free but the accomplice gets a long jail term (5 years). If you both confess the prosecutor will give you both a reduced sentence (4 years). If neither confesses you both get jailed for a lesser charge (2 years) which the police do have sufficient evidence for.

So what should you do? From your own point of view you should always confess because if your accomplice also confesses you get a lesser sentence (4 years instead of 5) and if your accomplice doesn’t you go free. But if both use this same strategy you will both get a higher sentence than you would if you both stayed silent (4 years instead of 2).

It’s called the prisoner’s dilemma and is an example of the difference between individual and group rationality. But so what? Who cares about a game imagined by philosophers? Does this have any actual relevance in the real world? Well I guess it could if you were in the exact situation described but, as I hope you will have guessed, the underlying issue goes away beyond that.

A lot of the original research in the related branch of maths, game theory, was done to understand the possible ramifications of nuclear deterrent strategies int he 1950s. So this is serious stuff. And it’s relevant today too, even after the end of the cold war.

Let’s apply the same type of idea to environmental issues (such as global warming) and to social issues (such as accumulation of wealth). The “players” in these games can make decisions to undermine the rights of others for their own benefit (such as catching fish of an endangered species) and as long as others don’t do the same they do well (the fishery is partly depleted which is a loss for others, but they gain a lot of profit which is a big gain for them) except if too many people use the same strategy (and why wouldn’t they) everyone is worse off because the profit is less and the fishery is destroyed.

More generally note that this is an undeniable proof that libertarian ideology doesn’t work. Libertarianism relies on the individual making rational decisions which are also good for the majority, but clearly even if an individual makes a rational decision (which is extremely questionable in itself) there are many situations (I would say the majority and maybe all) where that is not the best for the group at all.

So it’s in the maths, and maths doesn’t lie! Libertarianism and the neo-liberal economic agenda can never work, for those two very good reasons (individual good doesn’t map to group good, and rationality is far from guaranteed).

The question then becomes how can the optimal group rationality be applied when people tend to act to maximise individual rationality (if they act rationally at all). That’s the hard question, of course, because group oriented government hasn’t been conspicuously successful.

But that’s assuming that you equate extreme Soviet style socialism with a true group oriented political system. I don’t. Saying group oriented control has failed because the Soviet bloc failed is a straw man argument. We need to work towards a much better system than that but again I’m not sure what it should be.

But whatever it is we need to start by admitting that the current system of individuals maximising their personal power and wealth is not the optimal solution for the majority. That way most of us really are prisoners.

Advertisements
  1. No comments yet.
  1. No trackbacks yet.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: