Parents influence their children in many ways, but which family features actually cause the strong intergenerational linkages that we observe? This column presents the first causal evidence on cognitive skill transmission in the family. Using Dutch survey and registry data, the authors show that parents’ maths and language skills strongly affect the same skills in their children, and that skills within dynasties are not just genetically determined but are significantly affected by educational experiences. This highlights the importance of good educational environments in alleviating persistent inequalities.