Ecology

Biology

Closeness

Taboo

Computer science

Anthropology

Business

Psychology

Mathematics

Sociology

Mathematical analysis

Sociality

Knowledge management

Proceedings of the National Academy of Sciences

Significance Humans are an unusually cooperative species, and our cooperation is of 2 kinds: altruistic, when actors benefit others at a cost to themselves, and mutualistic, when actors benefit themselves and others simultaneously. One major form of mutualism is coordination, in which actors align their choices for mutual benefit. Formal examples include meetings, division of labor, and legal and technological standards; informal examples include friendships, authority hierarchies, alliances, and exchange partnerships. Successful coordination is enabled by common knowledge: knowledge of others’ knowledge, knowledge of their knowledge of one’s knowledge, ad infinitum. Uncovering how people acquire and represent the common knowledge needed for coordination is thus essential to understanding human sociality, from large-scale institutions to everyday experiences of civility, hypocrisy, outrage, and taboo.

Common knowledge, coordination, and strategic mentalizing in human social life