At some point our evolutionary past (exactly when is debated, though most would say within the last 200 ky years or so), our ancestors began to regularly produce material symbols (e.g., jewellery, parietal art, etc.). As yet, there's no widely accepted account as to what drove this intuitively crucial evolutionary transition. In this talk, I sketch two new lines of thinking about the origins of material symbol use, with an eye towards solving some outstanding puzzles in this area. (Among them: why do material symbols take so long to appear in the archaeological record, especially if (proto-)language evolved quite a lot earlier, as many now argue?) The first line of thought examines the role of material symbols in producing and maintaining common knowledge within and between human social groups. Put simply, common knowledge is not just shared information (as when each of the members of some collective have all received the same message); rather, it is shared information that is known to be shared. (Think of the sounding of a village bell on the hour: to a good approximation, it not only tells all the villagers the time; it tells all the villagers that it tells all the villagers the time.) The second concerns the distinctively normative dimension of material symbol use. In particular, by publicly donning a symbol that's indicative of a particular status, an individual opens themselves up to sanction by those who would contest that status. (Think of a bikie patch or other gang symbol worn in public.) As a result, the absence of third-party sanctioning effectively serves to ratify the individual's claimed status, in way that is plain for all to see. I shall also briefly consider how these two lines of thought interrelate, though my main goal is to establish the relevance of each singly.

About the Speaker
Dr Ronald J. Planer is Lecturer in the School of Liberal Arts at the University of Wollongong. He researches the natural history of human social and cognitive evolution.   

Presented as part of the School of Archaeology and Anthropology's 2025 Biological Anthropology Research (BAR) Seminar series.