The Influence of Extended Kin on Educational Achievement: An Examination of Cousin Order and Cousin Group Size

Despite growing interest in the potential influence of grandparents on grandchild status attainment, research has not addressed whether the ordinal position or number of grandchildren affects outcomes. The authors apply sibling and cousin fixed effects analyses to Swedish population data (cohorts born 1972–2003; N = 2,326,309), to examine how cousin order and cousin group size influence grade point average (GPA) percentile rank at the end of compulsory school. In sibling fixed effects analyses, second-born, fifth-born, and tenth or later–born maternal cousins achieve GPA ranked scores 0.66, 1.04, and 1.29 percentile points lower than firstborn cousins, respectively. Results for paternal cousins are weaker, suggesting greater influence from the mother’s extended family. In further analyses, the authors examine whether a twin birth to an aunt or uncle has any impact on GPA percentile rank. Instrumental variable analyses indicate that an increase in maternal cousin group size has a statistically significant negative effect on GPA rank at low parities; the effects of an increase in paternal cousin group size are less consistent.