Lynn’s (2010) attribution of decreasing north-to-south PISA scores and GDP in Italy to inherited intelligence caused debate, but cognitive-capitalism’s tenet that regional/national intelligence, inherited or not, determines provincial/country wealth remains unchallenged. We introduce a new theory into the debate and test a UV radiation → intelligence → socioeconomic latent variable (SELV) model vis-à-vis a radiation → SELV → intelligence one. Only the latter is found well-adjusted in Italy, more so among adolescents than children. Since hair and eye color vary with latitude in Italy and UV radiation could be a proxy for ancestry, the models are retested among White students in the USA. Similar results observed suggest that, in both countries, increased UV radiation impairs socio-economic development, perhaps by reducing industriousness through oxidative stress. The ensuing l...

A debate in Mankind Quarterly positing racial categorization of populations vis-à-vis biological effects of UV radiation was based on data from a single country, used absolute latitude instead of UV radiation, and limited the analysis to path analysis. To overcome limitations of the studies, we utilized measurements of UV radiation for 26 Brazilian and 48 USA states instead of absolute latitude and performed seemingly unrelated regressions in addition to path analysis. NAEP scores and infectious disease rate were collected in USA and PISA scores and infant mortality in Brazil. Significant cognitive effects of European ancestry were replicated, but showed spuriousness, disappearing when the effects of UV radiation were controlled. Our evidence strongly suggests that UV radiation is a consistent antecedent of cognitive ability directly and through income in the USA and Brazil and through ...