Research has already established that there are four main forms of “reciprocity” that drive people to behave prosocially: wanting to do something nice for somebody who had been kind to you (direct reciprocity); doing good in the presence of people who might reward your generosity (reputational giving); paying it forward after experiencing kindness yourself (generalised reciprocity); or doing something for someone you’d seen be generous (rewarding reputation).
But most of these motivations have been studied individually: what happens when — as in real life — they all occur at once? In a new study published in Science Advances, David Melamed and colleagues find that people intrinsically want to help each other — even when those drivers seem like they are competing with one another.
“From an evolutionary perspective, it’s kind of perplexing that it even exists, because you’re decreasing your own fitness on behalf of others,” Melamed concludes. “And yet, we see it in bees and ants, and humans and throughout all of nature.”



