The Network Dynamics of Category Formation.

How do separate cultures arrive at similar category systems across a wide range of semantic domains? Foundational work in cognitive science argues that cross-cultural coherence in category systems emerges because people independently produce the same categories as a result of universal psychological processes. Category coherence across cultures is thus viewed as incompatible with social theories of categorization, which argue that categories are defined contextually through communication, leading to highly divergent (i.e. path dependent) category systems. Here, we present findings from a novel study of real-time category formation to demonstrate that social processes can give rise to divergence and convergence in category systems among experimental micro-cultures, depending on the size of the social network individuals are communicating in. In this study, we used an online web platform to experimentally control the size of people's social networks as they collaboratively categorized a novel continuum of arbitrary shapes. In dyads (N=2), communication generated highly divergent category systems, but in social networks (N=50), it led independently replicated populations to consistently converge on remarkably similar category systems. In networks, individuals were more likely to produce and adopt labels that were better at coordinating with any random person in the network, leading the same subset of categories to diffuse in separate populations. These results challenge the longstanding view that processes of social construction lead to path dependency, by showing that category coherence across cultures may be attributable to processes of social coordination and diffusion in communication networks. [ABSTRACT FROM AUTHOR]