In many countries, the Sixties marked a turning point in the history of women’s emancipation, notably with the liberalization of contraception. Using French surveys with information on the birth order of large samples of individuals born after 1945, we show that the first to be affected by this revolution were the first-born of the early 1960s: they grew up much more often in "modern" families (two children max, working mother) than children of higher birth orders born at the same time in other families. However, this change in family environment did not coincide with any decline in their educational achievement.