The formal schooling niche: Longitudinal evidence from Bolivian Amazon demonstrates that higher school quality augments differences in children's abstract reasoning.

Although it is widely accepted that abstract reasoning and schooling are crucial for occupational success and human capital development in wage-based labor markets, the pathways by which schooling affects cognition remain unclear. This study examines the effects of a pervasive cultural institution, formal schooling, on the development of children’s abstract reasoning skills over a four-year period in the Bolivian Amazon (n=290 children; 8-18 years; 42% female). Assessing school attributes, children’s school-derived skills and nutritional status, and parental factors on children’s abstract reasoning, we find that children attending higher quality schools score higher on abstract reasoning assessments relative to children attending low-quality schools. Performance gaps persist and increase over time, suggesting that higher school quality is a positive and more important causal determinant of abstract reasoning than many child- and family-level characteristics during population transitions to obligate formal schooling.