The Prisoner’s Dilemma

It’s a classic thought experiment, mathematical problem and a cause of much philosophical debate. Over the years it has found its way into every sphere of existence from serious lecturing to game shows to, on numerous occasions, real life. It has been argued as being the basis for all religion, and its place in our society. And to think that it, in its purest form, is nothing more than a story about two men in a jail- the prisoner’s dilemma.

The classic example of the dilemma goes roughly as follows; two convicts suspected of a crime are kept in single custody, separated from one another and unable to converse. Both are in fact guilty of the crime, but the police only have evidence to convict them for a small charge, worth a few months in jail if neither of them confess (the ‘cooperation’ option). However, if they ‘rat out’ on their partner, they should be able to get themselves charged with only a minor offence for complicity, worth a small fine, whilst their partner will get a couple of years behind bars. But, if both tell on one another, revealing their partnership in the crime, both can expect a sentence of around a year.

The puzzle comes under the title (in mathematics) of game theory, and was first formally quantified in the 1950s, although the vague principle was understood for years before that. The real interest of the puzzle comes in the strange self-conflicting logic of the situation; in all cases, the prisoner gets a reduced punishment if they rat out on their partner (a fine versus a prison sentence if their partner doesn’t tell on them, and one year rather than two if they do), but the consequence for both following the ‘logical’ path is a worse punishment if neither of them did. Basically, if one of them is a dick then they win, but if both of them are dicks then they both lose.

The basic principle of this can be applied to hundreds of situations; the current debate concerning climate change is one example. Climate change is a Bad Thing that looks set to cause untold trillions of dollars in damage over the coming years, and nobody actively wants to screw over the environment; however, solving the problem now is very expensive for any country, and everyone wants it to be somebody else’s problem. Therefore, the ‘cooperate’ situation is for everyone to introduce expensive measures to combat climate change, but the ‘being a dick’ situation is to let everyone else do that whilst you don’t bother and reap the benefits of both the mostly being fixed environment, and the relative economic boom you are experiencing whilst all the business rushes to invest in a country with less taxes being demanded. However, what we are stuck with now is the ‘everyone being a dick’ scenario where nobody wants to make a massive investment in sustainable energy and such for fear of nobody else doing it, and look what it’s doing to the planet.

But I digress; the point is that it is the logical ‘best’ thing to take the ‘cooperate’ option, but that it seems to make logical sense not to do so, and 90% of the moral and religious arguments made over the past couple of millennia can be reduced down to trying to make people pick the ‘cooperate’ option in all situations. That they don’t can be clearly evidenced by the fact that we still need armies for defensive purposes (it would be cheaper for us not to, but we can’t risk the consequences of someone raising an army to royally screw everyone over) and the ‘mutually assured destruction’ situation that developed between the American and Soviet nuclear arsenals during the Cold War.

Part of the problem with the prisoner’s dilemma situation concerns what is also called the ‘iterative prisoner’s dilemma’- aka, when the situation gets repeated over and over again. The reason this becomes a problem is because people can quickly learn what kind of behaviour you are likely to adopt, meaning that if you constantly take the ‘nice’ option people will learn that you can be easily be beaten by repeatedly taking the ‘arsehole’ option, meaning that the ‘cooperate’ option becomes the less attractive, logical one (even if it is the nice option). All this changes, however, if you then find yourself able to retaliate, making the whole business turn back into the giant pissing contest of ‘dick on the other guy’ we were trying to avoid. A huge amount of research and experimentation has been done into the ‘best’ strategy for an iterative prisoner’s dilemma, and they have found that a broadly ‘nice’, non-envious strategy, able to retaliate against an aggressive opponent but quick to forgive, is most usually the best; but since, in the real world, each successive policy change takes a large amount of resources, this is frequently difficult to implement. It is also a lot harder to model ‘successful’ strategies in continuous, rather than discrete, iterative prisoner’s dilemmas (is it dilemmas, or dilemmae?), such as feature most regularly in the real world.

To many, the prisoner’s dilemma is a somewhat depressing prospect. Present in almost all walks of life, there are countless examples of people picking the options that seem logical but work out negatively in the long run, simply because they haven’t realised the game theory of the situation. It is a puzzle that appears to show the logical benefit of selfishness, whilst simultaneously demonstrating its destructiveness and thus human nature’s natural predisposition to pursuing the ‘destructive’ option. But to me, it’s quite a comforting idea; not only does it show that ‘logic’ is not always as straightforward as it seems, justifying the fact that one viewpoint that seems blatantly, logically obvious to one person may not be the definitive correct one, but it also reveals to us the mathematics of kindness, and that the best way to play a game is the nice way.

Oh, and for a possibly unique, eminently successful and undoubtedly hilarious solution to the prisoner’s dilemma, I refer you here. It’s not a general solution, but it’s still a pretty cool one 🙂

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3500 calories per pound

This looks set to be the concluding post in this particular little series on the subject of obesity and overweightness. So, to summarise where we’ve been so far- post 1: that there are a lot of slightly chubby people present in the western world leading to statistics supporting a massive obesity problem, and that even this mediocre degree of fatness can be seriously damaging to your health. Post 2: why we have spent recent history getting slightly chubby. And for today, post 3: how one can try to do your bit, especially following the Christmas excesses and the soon-broken promises of New Year, to lose some of that excess poundage.

It was Albert Einstein who first demonstrated that mass was nothing more than stored energy, and although the theory behind that precise idea doesn’t really correlate with biology the principle still stands; fat is your body’s way of storing energy. It’s also a vital body tissue, and is not a 100% bad and evil thing to ingest, but if you want to lose it then the aim should simply be one of ensuring that one’s energy output, in the form of exercise  exceeds one’s energy input, in the form of food. The body’s response to this is to use up some of its fat stores to replace this lost energy (although this process can take up to a week to run its full course; the body is a complicated thing), meaning that the amount of fat in/on your body will gradually decrease over time. Therefore, slimming down is a process that is best approached from two directions; restricting what’s going in, and increasing what’s going out (both at the same time is infinitely more effective than an either/or process). I’ll deal with what’s going in first.

The most important point to make about improving one’s diet, and when considering weight loss generally, is that there are no cheats. There are no wonder pills that will shed 20lb of body fat in a week, and no super-foods or nutritional supplements that will slim you down in a matter of months. Losing weight is always going to be a messy business that will take several months at a minimum (the title of this post refers to the calorie content of body fat, meaning that to lose one pound you must expend 3500 more calories than you ingest over a given period of time), and unfortunately prevention is better than cure; but moping won’t help anyone, so let’s just gather our resolve and move on.

There is currently a huge debate going on concerning the nation’s diet problems of amount versus content; whether people are eating too much, or just the wrong stuff. In most cases it’s probably going to be a mixture of the two, but I tend to favour the latter answer; and in any case, there’s not much I can say about the former beyond ‘eat less stuff’. I am not a good enough cook to offer any great advice on what foods you should or shouldn’t be avoiding, particularly since the consensus appears to change every fortnight, so instead I will concentrate on the one solid piece of advice that I can champion; cook your own stuff.

This is a piece of advice that many people find hard to cope with- as I said in my last post, our body doesn’t want to waste time cooking when it could be eating. When faced with the unknown product of one’s efforts in an hours time, and the surety of a ready meal or fast food within five minutes, the latter option and all the crap that goes in it starts to seem a lot more attractive. The trick is, therefore, to learn how to cook quickly- the best meals should either take less than 10-15 minutes of actual effort to prepare and make, or be able to be made in large amounts and last for a week or more. Or, even better, both. Skilled chefs achieve this by having their skills honed to a fine art and working at a furious rate, but then again they’re getting paid for it; for the layman, a better solution is to know the right dishes. I’m not going to include a full recipe list, but there are thousands online, and there is a skill to reading recipes; it can get easy to get lost between a long list of numbers and a complicated ordering system, but reading between the lines one can often identify which recipes mean ‘chop it all up and chuck in some water for half an hour’.

That’s a very brief touch on the issue, but now I want to move on and look at energy going out; exercise. I personally would recommend sport, particularly team sport, as the most reliably fun way to get fit and enjoy oneself on a weekend- rugby has always done me right. If you’re looking in the right place, age shouldn’t be an issue (I’ve seen a 50 year old play alongside a 19 year old student at a club rugby match near me), and neither should skill so long as you are willing to give it a decent go; but, sport’s not for everyone and can present injury issues so I’ll also look elsewhere.

The traditional form of fat-burning exercise is jogging, but that’s an idea to be taken with a large pinch of salt and caution. Regular joggers will lose weight it’s true, but jogging places an awful lot of stress on one’s joints (swimming, cycling and rowing are all good forms of ‘low-impact exercise’ that avoid this issue), and suffers the crowning flaw of being boring as hell. To me, anyway- it takes up a good chunk of time, during which one’s mind is so filled with the thump of footfalls and aching limbs that one is forced to endure the experience rather than enjoy it. I’ll put up with that for strength exercises, but not for weight loss when two far better techniques present themselves; intensity sessions and walking.

Intensity sessions is just a posh name for doing very, very tiring exercise for a short period of time; they’re great for burning fat & building fitness, but I’ll warn you now that they are not pleasant. As the name suggest, these involve very high-intensity exercise (as a general rule, you not be able to talk throughout high-intensity work) performed either continuously or next to continuously for relatively short periods of time- an 8 minute session a few times a week should be plenty. This exercise can take many forms; shuttle runs (sprinting back and forth as fast as possible between two marked points or lines), suicides (doing shuttle runs between one ‘base’ line and a number of different lines at different distances from the base, such that one’s runs change in length after each set) and tabata sets (picking an easily repeatable exercise, such as squats, performing them as fast as possible for 20 seconds, followed by 10 seconds of rest, then another 20 seconds of exercise, and so on for 4-8 minute) are just three examples. Effective though these are, it’s difficult to find an area of empty space to perform them without getting awkward looks and the odd spot of abuse from passers-by or neighbours, so they may not be ideal for many people (tabata sets or other exercises such as press ups are an exception, and can generally be done in a bedroom; Mark Lauren’s excellent ‘You Are Your Own Gym’ is a great place to start for anyone interested in pursuing this route to lose weight & build muscle). This leaves us with one more option; walking.

To my mind, if everyone ate properly and walked 10,000 steps per day, the scare stats behind the media’s obesity fix would disappear within a matter of months. 10,000 steps may seem a lot, and for many holding office jobs it may seem impossible, but walking is a wonderful form of exercise since it allows you to lose oneself in thought or music, whichever takes your fancy. Even if you don’t have time for a separate walk, with a pedometer in hand (they are built into many modern iPods, and free pedometer apps are available for both iPhone and Android) and a target in mind (10k is the standard) then after a couple of weeks it’s not unusual to find yourself subtly changing the tiny aspects of your day (stairs instead of lift, that sort of thing) to try and hit your target; and the results will follow. As car ownership, an office economy and lack of free time have all grown in the last few decades, we as a nation do not walk as much as we used to. It’s high time that changed.