6.6 Contagion as Social Cohesion

It is possible that joy contagion evolved to encourage social cohesion. In their 2021 review paper on play vocalizations and laughter, Sasha Winkler and Gregory Bryant explore the literature of play vocalizations in 65 mammalian species. In cases where laughter appears to serve a specific function, it is demonstrated to either 1) encourage one’s play partner to continue a current action (e.g., tickling or wrestling) or 2) signal to one’s play partner that the following actions are not malicious – even if they mimic typically aggressive or violent behaviors. By signaling this lack of maliciousness in one’s behavior, common behaviors like play fighting, wrestling, or chasing can take place without misunderstanding.

Primatologist Isabel Behncke suggests that laughter and play do, in fact, have an important role in the cohesion of social groups. With clear rules, opportunities to practice conflict resolution, and sharing of joy with others, play may be a crucial aspect of primate evolution and a necessity to address societies current and future concerns.

Watch Behncke’s Ted talk, “Evolution’s gift of play, from bonobo apes to humans,” to learn more about how play can inspire creativity and social problem solving.