Plenary speaker

FreeHS is honored to invite Dr. Edward Hagen, Professor of Anthropology at Washington State University as our plenary speaker. The plenary talk will be held from 11:30 AM - 12:30 PM on 08 November. 

The evolution of "recreational" substance use: Dramatic age and sex differences and the tradeoff between drug toxicity and antiparasitic benefits

Abstract: Psychoactive drugs are widely used, it is thought, because they hijack reward-related neural circuitry. If so, drugs should be equally appealing to children and to adults of both sexes. Many drugs, however, are plant defensive chemicals. Hence, children, and to a lesser extent adult women, should have evolved to avoid consuming them to protect their, or their fetuses' and nursing infants', developing nervous systems, respectively. Analyses of national and cross-national data find virtually no substance use among children, a switch-like transition to substance use in adolescence, and a nearly universal male bias in substance use. They also find that various reproductive indices, such as total fertility rate and age of the youngest child, are negatively associated with women's substance use, even after controlling for indices of women’s social, economic, and educational status. These results suggest that protection of fetuses and nursing infants helps explain female drug use decisions. The onset of substance use in almost all adolescents of both sexes might be explained by the diminishing developmental costs of toxin exposure vs. its increasing antiparasitic benefits in ancestral environments, a hypothesis supported by experimental studies among Congo Basin hunter-gatherers.