Reciprocal altruism: Why we form relationships with non-relatives

It was the birthday of a co-worker of Monica’s. It had been four years now them working together. Previously, they just used to greet each other on their respective birthdays. But this year Monica’s friend gave her a gift on her birthday. Monica felt compelled to the same for her friend, even though she’d never done it before.

When someone does a favor for us, why do we feel tempted to return it?

Why are we likely to help those who’ve helped us before?

Why do we tend to buy gifts for those who do the same for us?


Reciprocal altruism

One should expect altruistic acts from one’s immediate family- one’s closest genetic relatives. This is because by helping each other survive and reproduce, a family is essentially helping its shared genes to successfully pass on to the next generation.

But what explains altruism outside of the family?

Why do people form close bonds with those who’re not related to them?

It’s all due to a psychological phenomenon known as reciprocal altruism. In simple words, reciprocal altruism is nothing but mutual benefit. We form bonds with people and help them so that we may get helped in return. Friendships simply can’t exist without the prospect of mutual benefit.


Origins of reciprocal altruism


During most of our evolutionary history, hunting was the main activity for procuring food. But success from hunting was unpredictable and erratic. One week a hunter would obtain more meat than required and another week he’d acquire nothing at all.

Add to this the fact that meat can’t be stored for long and is easily spoiled. Our hunter ancestors, therefore, could only survive if they somehow ensured a continual supply of food.

This generated selection pressure for reciprocal altruism, meaning that those who had mutual altruistic tendencies were more likely to survive and out-reproduce those who did not have such tendencies. 

Those who were helped helped others in the future. Therefore, altruistic tendencies are widespread amongst today’s humans.

Reciprocal altruism is found in the animal kingdom too. 

Chimpanzees, our closest cousins, form alliances to boost their chances of survival and reproduction. A dominant male-male alliance in chimps is likely to out-reproduce other males.

Vampire bats that suck cattle blood at night don’t always succeed. It has been observed that these bats provide regurgitated blood to their ‘friends’ when they’re in dire need. These ‘friends’ are bats who had provided them with blood in the past! They form close associations with each other even though they’re unrelated.


Shadow of the future

Reciprocal altruism is likely to occur when there’s a large shadow of the future. If the other person thinks that they’ll be interacting with you frequently in the extended future, then they have a strong incentive to be altruistic towards you. They expect you’ll be altruistic towards them in the future too.

On the other hand, if the other person thinks that they won’t be interacting with you for long (i.e. a small shadow of the future), then there seems to be no point in being altruistic.

This is one reason why most friendships in schools and colleges happen at the beginning of the academic year and not when the course is nearing its end.

In the beginning, students seek other students who might benefit them during the course. There’s simply no point in making friends when you’re hardly going to interact in the future.

If it looks like a friend is going to be altruistic towards you beyond college, then you’re likely to form a lifelong bond with that friend. If a friend has helped you a lot in the past and so have you, then you’re likely to form a lifelong friendship with them because you’ve both already demonstrated your respective commitment to reciprocal altruism.

When there’s no future to look forward to, chances of reciprocal altruism are less. It’s all about mutual benefit.
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