Drivers of technological richness in prehistoric Texas: an archaeological test of the population size and environmental risk hypotheses

This paper reports a study that sheds light on an issue that is important for understanding human behavioral evolution-the factors that influence hunter-gatherers' decisions regarding the number and degree of specialization of their tools. Two primary drivers of technological richness and complexity have been proposed in the anthropological literature: population size and environmental risk. In general, ethnographic studies tend to support environmental risk as the primary driver, whereas the limited number of archaeological studies that have been carried out seem to support population size. These findings are difficult to reconcile because problems exist for both sets of studies. The present study was designed with these problems in mind. We used an archaeological dataset to test which of the hypothesized driving factors-population size or environmental risk-best explains changes in technological richness. More specifically, we investigated whether changes in the number of point types in Texas from the first occupation more than 13,000 years ago to the Late Prehistoric period, around 400 years ago, are better explained by environmental risk or by population size. Bivariate correlations and a generalized linear model indicate that temporal changes in point-type richness in Texas are significantly associated with changes in one of our proxies of risk-global temperature. We found no relationship between temporal changes in point-type richness and changes in population size. Thus, the results derived from this study are consistent with the environmental risk hypothesis and inconsistent with the population size hypothesis.