Do testosterone declines during the transition to marriage and fatherhood relate to men's sexual behavior? Evidence from the Philippines

Do testosterone declines during the transition to marriage and fatherhood relate to men's sexual behavior? Evidence from the Philippines
Lee T Gettler et al.; November 2013
Hormones and Behavior


Abstract

Testosterone (T) is thought to help facilitate trade-offs between mating and parenting in humans. Across diverse cultural settings married men and fathers have lower T than other men and couples' sexual activity often declines during the first years of marriage and after having children. It is unknown whether these behavioral and hormonal changes are related. Here we use longitudinal data from a large study in the Philippines (n = 433) to test this model. We show that among unmarried non-fathers at baseline (n = 153; age: 21.5 ± 0.3 years) who became newly married new fathers by follow-up (4.5 years later), those who experienced less pronounced longitudinal declines in T reported more frequent intercourse with their partners at follow-up (p < 0.01) compared to men with larger declines in T. Controlling for duration of marriage, findings were similar for men transitioning from unmarried to married (without children) (p < 0.05). Men who remained unmarried and childless throughout the study period did not show similar T-sexual activity outcomes. Among newly married new fathers, subjects who had frequent intercourse both before and after the transition to married fatherhood had more modest declines in T compared to peers who had less frequent sex (p < 0.001). Our findings are generally consistent with theoretical expectations and cross-species empirical observations regarding the role of T in male life history trade-offs, particularly in species with bi-parental care, and add to evidence that T and sexual activity have bidirectional relationships in human males.

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Conclusion

In sum, we found that newly married new fathers who experienced greater declines in T also reported less frequent sexual intercourse with their partners at follow-up, 4.5 years later. We also showed that men who engaged in frequent sexual activity both before and after becoming married fathers experienced milder declines in T compared to less sexually active men, which suggests that sexual behavior could also have long-term implications for T production. This finding is consistent with the increasingly recognized observation that relationships between hormones and social behavior are likely reciprocal, rather than uni-directional. To our knowledge, these results are the first longitudinal evidence relating marriage/fatherhood-driven T decreases to men's sexual behavior.