School of Rocks: a Transmission Time Investment Model for Pleistocene Lithic Technology

Abstract

We propose a transmission time investment model for integrating the tenets of human behavioral ecology and cultural evolutionary theory to investigate agency and optimality in the social transmission of lithic technologies. While the cultural transmission process is often overlooked in discussions of optimality, we view it as a critical area for the application of adaptive reasoning to further understand the mechanisms responsible for change in lithic technologies. The proposed model modifies a technological intensification model based on the marginal value theorem (Bettinger et al. Journal of Archaeological Science, 33(4), 538–545, 2006; Mohlenhoff and Codding Evolutionary Anthropology, 26(5), 218–227, 2017) to explore how transmissibility may have affected the complexity of socially transmitted lithic production systems during the Pleistocene. This transmission investment model is contrasted with a passive demographic model derived from traditional explanations for changes in lithic technologies. To highlight how optimal considerations of transmissibility may have affected the long-term evolution of lithic technologies, we apply this model to three Pleistocene archaeological case studies investigating increases and decreases in lithic technological complexity. We propose that technological changes in each of these case studies is consistent with the predictions of the model, suggesting that time management strategies may have played a role in the long-term evolution of Pleistocene technologies. It is unlikely that transmission constraints alone were wholly responsible for the observed patterns, and future research should refine the measures of time availability and cost used here, as well as explore the interplay between transmission investment and other optimizing and social constraints.