To improve global human capital, an understanding of the interplay of endowment across the full range of socioeconomic status (SES) is needed. Relevant data, however, are absent in the nations with the most abject poverty (Tucker-Drob & Bates, 2016), where the lowest heritability and strong effects of SES are predicted. Here we report the first study of biopsychosocial gene–environment interaction in extreme poverty. In a sub-Saharan sample of early teenage twins (N = 3192), we observed substantial (~30–40%) genetic influence on cognitive abilities. Surprisingly, shared environmental influences were similar to those found in adolescents growing in Western affluent countries (25–28%). G × SES moderation was estimated at aˋ = .06 (p = .355). Family chaos did not moderate genetic effects but did moderate shared environment influence. Heritability of cognitive abilities in extreme poverty appears comparable to Western data. Reduced family chaos may be a modifiable factor promoting cognitive development.
