Using data from the Program for International Student Assessment of the Organization for Economic Cooperation and Development, this researcher finds that students living in intact families had higher math and reading scores than their peers from single-parent families and step parent families. Intact-family students had the highest math scores in 21 of 30 countries relative to students in both single-parent and step-parent families. In reading, intact-family students scored higher than single-parent students in 18 countries and higher than step-parent students in 26 countries. In the US, students from intact families scored on average 50 and 45.5 points higher on reading scores and 53 and 43 points higher on math scores than their peers from single-parent and step-parent families, respectively.
Family size, family type, and student achievement: Cross national differences and the role of socioeconomic and school factors. Journal of Comparative Family Studies 37 (Winter): 1-24.