Shared worlds and shared minds: A theory of collective learning and a psychology of common knowledge.

The study of observational learning, or learning from others, is a cornerstone of the behavioral sciences, because it grounds the continuity, diversity, and innovation inherent to humanity's cultural repertoire within the social learning capacities of individual humans. In contrast, collective learning, or learning with others, has been underappreciated in terms of its importance to human cognition, cohesion, and culture. We offer a theory of collective learning, wherein the cognitive capacity of collective attention indicates and represents common knowledge across group members, yielding mutually known representations, emotions. evaluations, and beliefs. By enhancing the comprehension of and cohesion with fellow group members, collective attention facilitates communication, remembering, and problem-solving in human groups. We also discuss the implications of collective learning theory for the development of collective identities, social norms, and strategic cooperation.