Using a household survey specially designed to analyze the complexity of family structures, we describe the intergenerational transmission of education in polygamous and monogamous unions in Senegal. The theoretical framework extends the standard quality / quantity trade-off by incorporating social norms that require parents with a given human capital to guarantee minimum levels of education to their offspring. Empirical results show that children of polygamous unions tend to receive less education, even after controlling for available resources (household income and the number of siblings). Though this may be due to unobserved preferences rather than to a causal impact of polygamy, other findings suggest that the institution of polygamy per se impacts investments in education. In particular, educated women do not transmit their education to their daughters when they live in polygynous unions.