Many living organisms, including humans, form groups. In behavioral ecology, it has been believed that individuals within a group cooperate with each other to search for food and escape from external enemies, increasing the probability of survival and resulting in the maintenance of the species. However, we always find contrarians (perverse individuals), which behave differently from everyone else. Why do contrarians arise in a group of living organisms where it would make the most sense for each member to be prosocial?

We thought that contrarians, outcasts from a group, who appear to be anarchic and disruptive to the group’s order, might play an essential role in the group. For example, contrarians take a less attractive option that the majority of the group does not choose, which is expected to resolve the overconcentration of the attractive option, reducing competition within the group. Furthermore, contrarians may greatly benefit the group as a whole in the long run by exploring and finding new resources and ideas, of which the group is not yet aware.

Through ecological, behavioral, genetic, neurophysiological, and psychological studies on various species, our research aims to demonstrate the idea that “diversity in the behavior and thinking of individuals within a group contributes not only to the benefit and happiness of the individuals but also to the benefit, stability, robustness, and flexibility of the group as a whole.”