In most developed countries, the fertility levels of parents and children are positively correlated. This article analyzes the strength of the intergenerational transmission of family size over the last century, including a focus on this reproduction in large and small families. Using the large-scale French Family Survey (2011), we show a weak but significant correlation of approximately 0.12–0.15, which is comparable with levels in other Western countries. It is stronger for women than men, with a gender convergence across cohorts. A decrease in intergenerational transmission is observed across birth cohorts regardless of whether socioeconomic factors are controlled, supporting the idea that the family of origin has lost implicit and explicit influence on fertility choices. As parents were adopting the two-child family norm, the number of siblings lost its importance for having two children, but it continues to explain lower parity and, above all, three-child families. This suggests that the third child has increasingly become an “extra child” (beyond the norm) favored by people from large families.