%0 Journal Article %A Richard Walker %A Anders Eriksson %A Camille Ruiz %A Taylor Howard Newton %A Francesco Casalegno %T Stabilization of cultural innovations depends on population density: testing an epidemiological model of cultural evolution against a global dataset of rock art sites and climate-based estimates of ancient population densities %D 2020 %R 10.1101/705137 %J bioRxiv %P 705137 %X Demographic models of human cultural evolution have high explanatory potential but weak empirical support. Here we use a global dataset of rock art sites and climate and genetics-based estimates of ancient population densities to test a new model based on epidemiological principles. The model focuses on the process whereby a cultural innovation becomes endemic in a population. It predicts that this cannot occur unless population density exceeds a critical value. Analysis of the data, using a Bayesian statistical framework, shows that the model has stronger empirical support than a null model, where rock art detection rates and population density are independent, or a proportional model where detection is directly proportional to population density. Comparisons between results for different geographical areas and periods yield qualitatively similar results, supporting the robustness of the model. Re-analysis of the rock art data, using a second set of independent population estimates, yields similar results. We conclude that population density above a critical threshold is a necessary condition for the maintenance of rock art as a stable part of a population’s cultural repertoire. Methods similar to those described can be used to test the model for other classes of archaeological artifact and to compare it against other models.Competing Interest StatementThe authors have declared no competing interest. %U https://www.biorxiv.org/content/biorxiv/early/2020/06/08/705137.full.pdf