Until now, few data made it possible to test links between knowledge and educational attainment in the adult population. Thanks to the 2004 Information and Daily Life Survey (Information et Vie Quotidienne: IVQ), we can better understand the determinants of educational attainment and skills acquisition, and compare their impact. Social origin remains very closely tied to educational attainment, but has a weaker influence on reading/writing and mathematical skills measured by the Survey. Children’s educational attainment also depends strongly on that of their parents, which is correlated with their occupational status. Allowing for this correlation, the father’s occupation does not have a major effect. Cultural origin measured by parental educational attainment, particularly that of the mother, is the chief determinant of children’s educational attainment and skills. As specifically regards skills, having an educated mother is a more powerful asset than having only an educated father. Educational-attainment differentials do not fully match skill differentials. The gaps observed are partly due to population groups with higher educational aspirations. Persons whose parents were born abroad, who learned to read in French, and who arrived in France as children, or were born in France, display higher educational attainment than other persons with the same socio-cultural origin, at a broadly comparable skill level. The influence of parental socio-demographic characteristics differs slightly by gender. Paternal occupation has a greater effect on the educational achievement and skills of girls than on those of boys. By contrast, maternal educational attainment has a somewhat stronger impact on sons than on daughters.