Uncertainty about social interactions leads to the evolution of social heuristics

Individuals face many types of social interactions throughout their lives, but they often cannot perfectly assess what the consequences of their actions will be. It is known that unpredictable environments can profoundly affect the evolutionary process, but it remains unclear how uncertainty about the nature of social interactions has shaped the evolution of social behaviour. By means of an evolutionary simulation model, we here show that even intermediate uncertainty leads to the evolution of simple cooperation strategies that disregard information about the social interaction at hand (‘social heuristics’). Moreover, the evolution of social heuristics greatly affects cooperation levels – in our simulations, increasing uncertainty nearly doubled the level of cooperation. These results provide new insight into why social behaviour, including cooperation in humans, is often observed to be seemingly suboptimal. More generally, our results show that social behaviour that seems maladaptive when considered in isolation may actually be well-adapted to a heterogeneous and uncertain world.status: publishe