I examine how one central aspect of the family environment—sibling sex composition—affects women’s gender conformity. Using Danish administrative data, I causally estimate the effect of having a second-born brother relative to a sister for first-born women. I show that women with a brother acquire more traditional gender roles as measured through their choice of occupation and partner. This results in a stronger response to motherhood in labor market outcomes. As a relevant mechanism, I provide evidence of increased gender-specialized parenting in families with mixed-sex children. Finally, I find persistent effects on the next generation of girls.

我研究了家庭环境的一个核心方面，即兄弟姐妹的性别构成，如何影响妇女的性别依从性。利用丹麦的行政数据，我有因果地估计了与第二胎兄弟相比，第二胎兄弟对第一胎妇女的影响。我表明，通过选择职业和伴侣来衡量，有兄弟的妇女获得了更多传统的性别角色。这导致对劳动力市场成果中的母性有更强的反应。作为一个相关的机制，我提供了有混血孩子家庭中按性别分性别的育儿增加的证据。最后，我发现了对下一代女孩的持久影响。