Social dynamics signals in archaeological time-series: How cultural transmission and production biases shape assemblage diversity.

High-resolution studies on scales of decades to centuries indicate that social systems shift to greater complexity and back, a phenomenon usually referred to as social cycles. In archaeological data, such cycles are reflected in the increase and decrease of diversity in material culture signals. However, the exact correlation between assemblage diversity cycles and social complexity remains unclear. Addressing this topic, our model investigates the impact of cultural transmission and production biases on the variation in material culture sets and explains how the observable variability in empirical evidence results from the same basic complex dynamic behavior. A single mathematical algorithm describes path-dependency, gradual changes, and rapid transformations of the empirically visible assemblage composition as the replacement of components of material culture in archaeological assemblages. Our simulations capture the direct impact of short-term fluctuations and delayed sensitive dependence on the initial conditions (chaotic effects) of the assemblage diversity. The model finds a decrease in variation (standardization) in assemblages to be an outcome of production bias, potentially reflecting changes in social complexity.