Why surprisingly? "Surprisingly, sons—and not daughters—have a systematic negative effect on feminist self‐identification & support for electing more women, & a positive effect on support for traditional gender roles"

The Effect of Children's Gender on Parents’ Attitudes Toward Women. Nicole Y. Wesley  James C. Garand. Social Science Quarterly, April 26 2021. https://doi.org/10.1111/ssqu.12976

Abstract: Scholars have found that the gender of children—particularly, having daughters—has a discernible effect on parents’ attitudinal and behavioral support for the empowerment of women. In this article, we explore how the gender of children affects the gender attitudes of parents. Using data from the 2016 American National Election Study (ANES) survey, we estimate the effects of children's gender on parents’ feminist self‐identification, support for more women representatives, and attitudes toward traditional gender roles, both in general and separately for men and women. Surprisingly, we find that sons—and not daughters—have a systematic negative effect on feminist self‐identification and support for electing more women, as well as a positive effect on support for traditional gender roles. The effects of sons on feminist self‐identification and traditional gender roles are observed for both men and women, while the effects of sons on support for more women representatives are limited to women. It appears that having a son decreases support for feminist and egalitarian gender attitudes in both men and women to varying degrees across a variety of dimensions.