My PhD dissertation studies the causes and consequences of family disruption in the lower strata of French society. In 1975, the rates of mothers raising a child under 18 years old alone were residual in all strata (around 6%). In 2019, the rates of single mothers skyrocketed to 29% among French lower-educated mothers, while they rose moderately to 13% among mothers with high education. In the US, the black family disruption has been reported by sociologists as soon as the 1960s. In France, the family disruption in disadvantaged social groups is more recent and still needs to be clarified and explained. Following Wilson’s thesis (1987), I investigate whether the family disruption is a response to basic economic changes that destabilized the working class in France by the end of the 1970s.