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It pays to be altruistic

21 April 2010

Selfless acts such as giving to charity or contributing to public goods have long puzzled behavioural scientists.  Evolutionarily, it’s difficult to explain behaviours which have no obvious benefit to the individual.

However, in a study published this week in the Royal Society journal Biology Letters,  Karolina Sylwester and Gilbert Roberts at Newcastle University’s Institute of Neuroscience suggest an answer – we act cooperatively in order to enhance our personal reputation.  The study shows that acting cooperatively can be thought of as an investment in a reputation, where the returns are increased gains due to the ‘investor’s’ enhanced status.

The researchers devised a game in which four participants contributed a quantity of ‘lab pounds’ into a public pool, which was then split equally amongst all players.  The contribution made by each participant was then revealed to each player, who was asked to select a preferred partner for the next stage of the game.  Perhaps unsurprisingly, those who had contributed the most to the pot in the first round were most commonly selected as preferred partners.  In the second round of the game, pairs of participants contributed lab money to a common pool again, which was either doubled and then split equally between the pair or, in ‘bonus rounds’, multiplied by eight and distributed to the players as before.

Overall, those who played the game cooperatively, maximising their own investment in the common pool, gained the best reputation and walked away from the experiment with greater quantities of cash.  This is the first time scientists have shown that investing in ones’ reputation – through acting altruistically – can have financial benefits.  While it is not implied that all cooperative behaviour is performed in the expectation of some later benefit, the experiment shows that at least in some situations, cooperation can be thought of as an adaptive strategy.