How does culture change? We unify disconnected explanations of change that focus either on individuals or on public culture under a theory of cultural evolution. By shifting our analytical lens from actors to public cultural ideas and objects, our theory can explain change in cultural forms over large and long frames of analysis using formal evolutionary mechanisms. Complementing this theory, the paper introduces a suite of novel methods to explain change in the historical trajectories of populations of cultural ideas/objects (e.g., music groups, hashtags, laws, technologies, and organizations) through diversification rates. We deploy our theory and methods to study the history of metal music over more than three decades, using a complete dataset of all bands active between 1968 and 2000. Over the course of its history, we find strong evidence that the genre has been fundamentally shaped by competition between ideas for the cognitive resources actors can invest in learning about and reproducing this cultural form over time.
Bernard Koch is a PhD candidate in the sociology department at UCLA. Inspired by pre-graduate work in evolutionary biology and bioinformatics, his research now uses computational approaches to examine cultural dynamics in fields as diverse as science and music. In his work on culture, he seeks to wed theories of cultural evolution and cognition with formal models of population change from biology. Other projects elucidate how the culture and organization of scientific fields (e.g., machine learning, IQ psychology) create ethical and epistemic challenges. Lastly, he has broad interests in Bayesian modeling, machine learning, networks, and causal inference. His research has been published at NeurIPS, WWW, Sociological Methodology, and Science, among other venues.