Christopher Eppig|Corey L. Fincher|Randy Thornhill
Parasite prevalence and the worldwide distribution of cognitive ability
University of New Mexico|University of New Mexico|University of New Mexico
study hypothesize worldwide distribution cognitive ability determined part variation intensity infectious diseases energetics standpoint developing human difficulty building brain fighting infectious diseases time metabolically costly tasks using three measures average national intelligence quotient iq found zeroorder correlation average iq parasite stress ranges r 076 r 082 p lt 00001 correlations robust worldwide well within five six world regions infectious disease remains powerful predictor average national iq temperature distance africa gross domestic product per capita several measures education controlled findings suggest flynn effect may caused part decrease intensity infectious diseases nations develop