He conducts research into human cultural evolution: explaining cultural change using the concepts, tools and methods of evolutionary theory. Specifically, he uses lab experiments and theoretical models to simulate the individual-level social learning processes – who copies what, from whom, and when – that generate large-scale patterns of cultural change and diversity. Much of his work has examined technological evolution, looking at arrowheads and handaxes. More recently he has been studying immigration as a source of cultural change and stasis. His 2011 book, Cultural Evolution, was his attempt to synthesise cultural evolution research across multiple disciplines to encourage a unified evolutionary science of culture