Do Fathers’ Sexual Behaviors Vary with the Sex of Firstborns? Evidence from 37 Countries

This article investigates whether men's sexual behavior is influenced by the sex of their firstborn children and, if so, at what stage of firstborns' development this occurs. Using standardized data from 37 Demographic and Health Surveys (N = 61,801), I compare the sexual activities, sexually transmitted infection symptoms, and sexual ideologies of fathers with firstborn sons and fathers with firstborn daughters. I also explore whether fathers' attitudes mediate the effects of firstborn sex. The findings indicate that fathers with firstborn sons are less likely to report using condoms and more likely to report paying for sex and having genital ulcers than fathers with firstborn daughters. These differences are limited to the firstborn's adolescent years and are slightly mediated by attitudinal differences. Together, these results raise new questions about the underlying mechanisms linking men's sexual behavior to their children's gendered development.