How Culture Drove Us Into the Cognitive Niche

Abstract

How have humans become such outliers in our behavioral flexibility and our rapid learning? How have our brains evolved to learn and reason in evolutionarily novel domains, such as mathematics and number systems, laws and mores, or science and medicine? In this dissertation, combining work in cognitive science and cultural evolution, I seek to answer such questions by building informational-ecological models that show how minds that perform different computational strategies fare under different conditions. In the first chapter, I show, using a simple and general model, that any species that is heavily dependent on social learning to acquire much of its adaptive behavior would evolve to make increasingly accurate generalizations. This in turn demands greater mental capacity to learn abstract concepts and world-models. This model ties the evolution of our brains directly to the fact that our babies can expect to be born into a world where they can learn from other skilled individuals. However, our nature as a cultural species has done more than just making available skilled models to learn from. Culture can shape our informational environments (i.e. informational niche construction) in other ways as well. In chapter two of my dissertation, I show how differences between cultural populations in communication styles, or in how knowledge flows across a population, can alter how information is sampled, in such a way as to explain computationally why different cultural groups develop Analytic or Holistic thought--a major distinction made by cross-cultural psychologists. In the third chapter, I extend this informational-ecological perspective to the physical world of tools and dwellings, and the social world of norms, institutions and organizations, to show how the phenomenon of standardization in cultural products is yet another form of informational-niche construction, with far-reaching consequences that explain a wide range of cross-cultural findings in cognitive psychology, sociology, anthropology and political science. One source of increasing standardization in a cultural system is increased population mobility, and on my final chapter, I present archaeogenetic work showing how an ancient episode of increased mobility has led to the development of just such a standardized suite of bronze weaponry that took on ritual, political and economic significance across Northern Eurasian societies in the Bronze Age.