Experimental studies of cumulative culture in modern humans: What are the requirements of the Ratchet?

Abstract

The success of Homo sapiens as a species may be explained, at least in part, by their learning abilities. The archaeological record suggests that the material culture of humans during the Palaeolithic was fluid and diverse. Social learning abilities may therefore have allowed Homo sapiens to adapt rapidly to novel or changeable environmental conditions. A capacity for cumulative cultural evolution is certainly apparent in all contemporary human societies, whereas it appears either absent or extremely rare in other extant species. Here I review laboratory studies of cumulative culture in modern adult humans, designed to shed light on the social information required for this type of learning to occur. Although it has been suggested that cumulative culture may depend on a capacity for imitation, we found that imitation (at least in the narrow sense of action copying) was not necessary for human participants to exhibit ratchet-like effects of improvement over learner generations. We discuss the need for high fidelity reproduction in cumulative culture (independent of action copying).