Fathers with less testosterone tend to have a better relationship with their partner, according to new research from Jamaica.

“I have long been interested in fathers,” said the study’s lead author, Peter B. Gray of University of Nevada, Las Vegas. “For Dr. Samms-Vaughan, coauthor on this study and a Jamaican pediatrician, part of her interest in fathers stems from seeking to understand the variables roles and potential influences of fathers on child development. This study is part of the fatherhood arm of a Jamaican birth cohort study in which an aim is to better understand variation in fathering as well as its causes and consequences within family relationships.”

The study, published in the journal Human Nature, found that relationship quality was negatively associated with fathers’ testosterone. In other words, fathers with higher testosterone levels tended to report having a poorer quality relationship with the mother of their child.

“This study contributes to what is know a sizable literature on men’s testosterone and family relationships,” Gray told PsyPost. “A key finding is that, among this sample of approximately 350 fathers of 18-24 month old children in Jamaica, men’s partnership quality was negatively related to their testosterone levels.”

“However, fathers’ relationship status (e.g., married, in a non-residential or visiting relationship) and measures of paternal attitudes and behavior and sexuality were not related to variation in fathers’ testosterone levels. For fathers of young children, access to and involvement with his child is often contingent upon the relationship with the child’s mother, perhaps helping explain why partnership quality but not other variables were related to fathers’ testosterone.”

Previous smaller studies have found that fathers tend to have lower testosterone levels than men without children. While the new study recruited a larger sample, Gray noted it still had limitations of its own.

“The study is cross-sectional and measures were based on structured interviews rather than observational or experimental,” he explained. “We had hoped to test whether stepfathers had higher testosterone levels than biological fathers but recruitment challenges of stepfathers prevented directly testing this hypothesis; we were able to show, in a weaker test of this hypothesis, that fathers who lived with partners’ (but not his own) children did not have higher testosterone levels than those who didn’t live with non-biological children. Thus, the hypothesis that stepfathers will have higher testosterone levels than biological fathers remains to be adequately tested.”

“Another question remaining to be addressed stems from the observation that many men are on some form of testosterone supplementation. No study, to my knowledge, has tested whether taking exogenous testosterone influences partnership or caregiving behaviors.”

Gray concluded: “Happy Father’s Day–to fathers in Jamaica, the U.S. and everywhere. ”

The study, “Testosterone and Jamaican Fathers: Exploring Links to Relationship Dynamics and Paternal Care“, was also co-authored by Jody Reece, Charlene Coore-Desai, Twana Dinall, Sydonnie Pellington, and Maureen Samms-Vaughan.