  Understanding how cooperative behaviours can emerge from competitive
interactions is an open problem in biology and social sciences. While
interactions are usually modelled as pairwise networks, the units of many
real-world systems can also interact in groups of three or more. Here, we
introduce a general framework to extend pairwise games to higher-order
networks. By studying social dilemmas on hypergraphs with a tunable structure,
we find an explosive transition to cooperation triggered by a critical number
of higher-order games. The associated bistable regime implies that an initial
critical mass of cooperators is also required for the emergence of prosocial
behavior. Our results show that higher-order interactions provide a novel
explanation for the survival of cooperation.
