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.