Studies on gene-by-family SES interaction (GxSES) in educational outcomes have produced mixed results. This study builds on a sociocontextual perspective, emphasizing that genetic influences are shaped by broader social forces besides family, including gender and institutional context. For example, some of the previous sociogenetic studies indicate that particularly early school tracking suppresses the genetic influences. We analyzed gene-by-environment interactions (GxE) by parental education and children's gender using large twin registers from Finland, Norway, Germany, and the Netherlands employing non-parametric gene-environment interaction models. Our results indicated that genetic influences in Germany were weaker and shared environmental effects stronger than in other countries. We did not find significant gender differences in genetic or environmental effects on educational attainment in the studied countries. Analyses of GxSES revealed that the interactions depend on gender and country context. For example, in some countries, we observed negative interaction among women, with the genetic effect being weaker among children from high-SES families. Among men, the results indicate that GxSES can have either a positive or a negative direction. We conclude that the institutional context and gender can shape gene-environment interactions related to educational attainment.