This paper revisits the role of human capital for economic growth among non-industrialised ethnic groups. We hypothesize that exposure to rare, natural events drives curiosity and prompts thinking in an attempt to comprehend and explain the phenomenon, thus raising human capital —directly and indirectly. We focus on total solar eclipses as one particular trigger of curiosity and empirically establish a robust relationship between their number and several proxies for economic prosperity: social complexity, technological level and population density. Variation in solar eclipse exposure is exogenous as their local incidence is randomly and sparsely distributed all over the globe. Moreover, unlike other natural phenomena, solar eclipses do not destroy capital, either human or physical. We also offer evidence compatible with the mechanism we propose, finding a more intricate thinking in ethnic groups more exposed to solar eclipses. In particular, we study the development of written language, the play of strategy games and the accuracy of the folkloric reasoning for eclipses.