How geography influences complex cognitive ability

• Published in: Intelligence (Norwood) Vol. 50; pp. 221 - 227
• Main Authors: León, Federico R., Burga-León, Andrés
• Format: Journal Article
• Language: English
• Published: New York Elsevier Inc 01.05.2015; Elsevier Science Ltd
• Subjects: Cognitive ability; Complex cognitive ability; Evolution; Genetics; Geography; Intelligence; Socioeconomic factors; Ultraviolet radiation; UVB radiation; Northeast Asia; Eastern Europe; Sub-Saharan Africa; Geography; Evolution; UVB radiation; Complex cognitive ability
• ISSN: 0160-2896; 1873-7935
• DOI: 10.1016/j.intell.2015.04.011

Evolutionary explanations for geography's influence on complex cognitive ability (CCA) imply virtually immutable components of between-nation IQ differences. Their weight vis-à-vis the weight of situational components was evaluated through an analysis of a 194-country data set. Additive effects of absolute latitude (AL) and longitudinal distance from Homo sapiens' cradle (LDC) explain Northeastern Asian higher, Sub-Saharan African lower CCAs. AL exerts cognitive influence directly and through socioeconomic development and evolutionary genetics whereas LDC does through evolutionary genetics; however, this occurs differently in Africa-Near East-Europe and elsewhere. The findings are understood assuming supremacy of contemporary UVB radiation→hormonal and climatic→socioeconomic mediators of the AL–CCA linkage whose effects are moderated by heterogeneous genetic and cultural adaptations to radiation and climate. Geography's cognitive effects are dynamic and public-policy actions may modify them. •This study tested the hypothesis that longitudinal distance from Homo sapiens cradle influences complex cognitive ability (CCA) and evaluated the relative contribution of evolutionary and contemporary factors as mediators of the effects of geography on CCA.•Additive effects of absolute latitude and longitudinal distance from Homo sapiens cradle explain Northeastern Asians higher and Sub-Saharan Africans lower CCAs.•Latitude influences CCA directly and through genetic distance from South Africa and socioeconomic development whereas longitude does through genetic distance, both differently in Africa-Near East-Europe and elsewhere in the world.•The findings are explained by contemporary cognitive influences of geography through UVB radiation-hormonal and climatic-socioeconomic mediators moderated by heterogeneous adaptations to radiation and climate along ancient human dispersal routes.