UCLA

Among the drivers and constraints on the evolution of complex hominin culture that have been proposed throughout the years, demographic factors have been particularly persistent, and they have recently again come to gain traction in the literature in the shape of the so-called treadmill model. The treadmill model connects cultural complexity to group size via a need to constantly “outrun a treadmill of cultural loss,” whose backward motion is caused by errors in culture transmission. The entrenchment of the treadmill explanation of cultural complexity, however, takes place against a background of critiques of the model and the presence of other explanatory propositions. This creates a need for deentrenchment: wider integration, elaboration, and critique of the premises of the treadmill model and the evidence advanced to validate it. We begin by reviewing the treadmill model, making an assessment of its current status, and then moving on to a more synthetic proposition by placing the model into the context of other models addressing the elaboration of cultural complexity.We end by considering the broader implications for the study of the evolution of culture and of human behavior to be gained from more integrated modeling of the various factors affecting cultural complexity.