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., 2006; Mohlenhoff and Codding, 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 changes in each of these cases can be understood as the result of time management strategies related to the social transmission process.

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 modi es a technological intensi cation model based on the marginal value theorem (Bettinger et al., 2006;Mohlenhoff and Codding, 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 changes in each of these cases can be understood as the result of time management strategies related to the social transmission process.