A quick note on 'altruism' in ultimatum games

I frequently come across people suggesting that results from ultimatum and dictator games ‘prove’ that humans are altruistic (which is stronger than ‘other-regarding’). Indeed, this at times seems to be the intent of the researchers, what with them calling punishers ‘altruistic punishers’ and all. I think this is dead wrong. Punishers are optimising over different time horizons and scales, sometimes time horizons and scales that transcend the laboratory, much to the chagrin of the researchers no doubt, but a behavioural psychology lab is very different to that of a natural scientist. Punishers may well be other regarding, may well be ethical and may well be ‘good people’, but altruism is a myth.


What are these ‘games’ that I speak of? A dictator game involves giving someone a sum of cash (say $100). They then offer an amount to another person. They can offer zero if they want. The split occurs and everyone walks away. In an ultimatum game if the passive party rejects the dictator’s offer then they both get zero. Hence in an ultimatum game the dictator has a larger incentive to offer a sum greater than zero in an ultimatum game. Theoretically, there should be no incentive to offer any money in a dictator game under a rational actor framework because individuals only maximise their own utility, which comes directly from maximising income.

Both of these games can be played multiple times over several rounds in which some of the recipients become dictators and vice versa. This introduces interesting dynamics where dictators know that recipients may become dictators later and stooge them if they don’t offer something in this round. Unfortunately, without some contract law or an infinite number of rounds, you never can be sure whether you won’t be the final dictator able to make off with a 100% take. In ultimatum games there is an incentive for recipients in the early rounds of repeated games to reject low offers to encourage higher offers in later rounds.

Two phenomena encourage some to regard behaviour in these games as ‘altruistic’. The first is when dictators in single round dictator games offer amounts greater than zero. This seems insane because there is no penalty to taking 100% of the dollars if you’re long term goal is to maximise your income. The second is when recipients reject offers greater than zero in single-round ultimatum games. This also seems insane because you won’t get a chance to make money off your decision to forgo income right now.

I propose the following more philosophically palatable explanation: these behaviours can be explained by the thinking of the ‘altruists’ extending beyond the confines of the laboratory. A recipient who receives a weak offer in a single-round ultimatum game might think: ‘if I don’t reject this dickhead now he is going to go out into the world and think he can stooge people whenever he can get away with it’. Similarly, a generous dictator might think: ‘I should offer more than zero so that this person thinks there are good people in the world and takes that attitude with them’. Researchers are reluctant to consider such explanation because they prefer the illusion that the experiment stops at the lab. But a psych lab is very different to a sealed room from of controlled particles.

 Such behaviour makes a lot of sense in a species that relies on collective action. You need to be able to trust your fellow primates and you need to be certain that if you behave like a dickhead one of your colleagues is going to come and discipline you.


This behaviour then is ‘other-regarding’ in the sense that it considers others because the flourishing of the group is good for the individual. Such behaviour is not theoretically undermined by the existence of super-selfish individuals. It makes evolutionary sense that you want a mix of collectivists and individualists in a social species. Sometimes you need people who take risks and do their own thing. Witness socialist countries where people have an equal share of poverty. Equally it is important to have collectivists to avoid things like the US economy, which a financial sector policy wonk acquaintance of mine once described as ‘driving at 80 miles an hour through mountain roads—exhilarating until you fall off’.     

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