Latin American students consistently score low on international tests of cognitive skills. In the PISA 2012 results, students in seven Latin American countries had an average score of 395 in mathematics, or about 100 points lower than the average score of 497 in four Scandinavian countries. We estimate the effect of socioeconomic characteristics on student scores in Latin America and Scandinavia and find that 50 points of the difference are explained by Latin American parents' lower average educational and socioeconomic characteristics, 25 points are explained by Latin America's weak cultural orientation toward reading books and the remaining 25 points are explained by the lower effectiveness of Latin American educational systems in teaching cognitive skills.