Combinatorial culture: a hominin adaptation detected through use-wear analysis

Human cultural adaptation is uniquely structured by combination and recombination, with the behaviours of cooperation, language, and composite material culture presented as key elements. The emergence of this combinatorial culture is poorly understood, with theoretical evidence suggesting an early Middle Pleistocene genesis within a variability selection framework. Searching for combinatorial culture is best approached by archaeological detection of its physical manifestation, in the form of lithics, which in antiquity were hafted to a handle. Building on the work of Rots (2010), this is shown to be best approached with experimentally informed lithic use-wear analysis. An extensive experimental program is undertaken, with the results from this reference data explored using heatmaps, density-based cluster analysis, and predictive modelling using multinomial logistic regression. These analytical approaches, along with blind testing, demonstrate that use-wear is a suitable method for the detection of experimental bifaces which have been hafted. Five bifaces from the Middle Pleistocene site of Beeches Pit, UK, are analysed using both a traditional use-wear approach, and with the use of the predictive models. While the results do not indicate hafting, they do show that two of the tools were used for butchery related tasks, and that one of the bifaces was used as a strike-a-light. The detection of a strike-a-light at Beeches Pit, extends the chronology of this technology by approximately 400,000 years. Strike-a-light technology also represents a form of combinatorial culture in its technological and social complexity.