We show that infectious disease is a major contributor to the worldwide distribution of human cognitive ability, as measured by psychometric IQ. In areas where infectious disease is high, average human intelligence tends to be lower, and in areas where infectious disease is low, average human intelligence tends to be higher. In separate studies, we tested this across world nations (chapter 2) and across states of the USA (chapter 3). In efforts to disseminate our research to wider audiences, I reviewed the findings contained in chapters 2 and 3 using language that is accessible to non-biologists (chapter 4). Although it contains no original research, this chapter makes our research more readily available to people in non-biological fields, such as economics and political science, who may be interested in our findings. An early prediction we made, based on our first analysis, was that infectious disease could account for the apparent link between IQ and rates of asthma that other research has discovered (chapter 5). Additionally, this chapter attempts to reconcile the predictions made by several related hypotheses.
Intelligence, Development, Parasite-stress hypothesis, Hygiene hypothesis, Asthma, Developmental stability, Cognitive development, Life History, Brain growth, Flynn Effect, Parasites, Biogeography
Level of Degree
UNM Biology Department
First Committee Member (Chair)
Second Committee Member
Third Committee Member
Eppig, Christopher. "Infectious disease and the worldwide distribution of IQ." (2011). https://digitalrepository.unm.edu/biol_etds/32