Cultural transmission : exploring the role of language and transmission pathways in social networks

Abstract

This thesis investigates previously underexamined or unexplored aspects of the cultural transmission process with the overall aim of advancing cultural evolutionary theory. The first study implements the linear transmission chains experimental design to systematically compare language versus demonstration as social transmission modes in adult and child chains. Despite its importance in social learning, language is extremely underexamined as a distinct mode of transmission. The results, however, illustrate that it supports the type of high-fidelity social transmission that is required for cumulative cultural evolution, especially in children. The second study examines social learning from a multi-generational perspective. By using a novel design, it investigates how the context of acquisition of a cultural trait affects the onward transmission of that trait. This is the first experimental instance in which onward transmission is examined. The findings suggest that a context-congruence bias impacts cultural transmission and it even modulates model-based biases. The context-congruence bias is the first factor found to link acquisition and onward transmission. The third study uses qualitative data to explore how cultural information flows in a real-world social network. It explains how the previously proposed transmission biases may impact acquisition and onward transmission, and how vertical congruence – the result of our proposed context-congruence bias – can lead to increased longevity and stability. By exploring cultural transmission at the level of the individual, we uncover new questions and present new hypotheses. As different social learning and teaching mechanisms are documented, their connection with trait longevity is also considered. In the final chapter, the implications of the studies are discussed, as are their possible limitations and the avenues for future research that arise from the findings.