A Sequential Canonical Cascade Model of Social Biogeography: Plants, Parasites, and People

This sequential canonical cascade model of social biogeography is an extension of an integrated model of human cognitive ecology (Cabeza de Baca and Figueredo Intelligence 47:63–71, 2014) that predicted state-level life history and cognitive abilities in Mexico. We integrate such population-level factors by utilizing a sample of 66 recognized national polities for which sufficiently complete information was available on all the variables modeled. These national polities were limited to those found in Europe, Asia, and Africa. The Americas and Australia were excluded to avoid sampling parts of the world that had recently undergone massive colonizations by human and nonhuman animals and plants from other zoogeographic zones, which might have disrupted the evolutionarily expected relations between physical, community, and social human ecologies. Data were obtained from national census databases and international organizations, and only national polities with complete data were analyzed, meaning that no missing data were imputed based on values from nearby or otherwise similar polities. This integrated model of social biogeography proposes that abiotic climatic factors in the physical ecology as well as biotic factors in the community ecology produce variations in subsistence and natural resources that then impact biometric markers of life history, triggering changes in social equality, within-group and between-group peace, sexual equality, macroeconomic diversification, and human capital. These effects, in turn, ultimately produce changes in brain volume and aggregate cognitive abilities. The final equation in our cascade model explains 88 % of the variance in aggregate cognitive abilities by supplying more detailed information on socioecological conditions than previous work.