New research suggests that men with higher levels of testosterone tend to devote more energy to keeping their romantic partners faithful and in a relationship with them. The study, published in the journal Physiology & Behavior, examined what is known as mate retention behavior.

“A great deal of research has previously focused on the role that testosterone (an androgen) plays in men’s mate-seeking and competition for mates,” explained study author Steven Arnocky, an associate professor and founding director of the Human Evolution Laboratory at Nipissing University, Canada.

“By contrast, very little research has examined whether testosterone relates to other forms of mating-relevant competition, such as effort aimed at retaining a mating partner. This includes benefit provisioning (e.g., doing nice things for your partner to highlight your commitment to her such as buying gifts, proposing marriage) and cost inflicting (e.g., threatening other men to stay away) acts meant to hold on to exclusive access to one’s mate.”

“This is an important gap in knowledge because unlike most other mammalian species, humans generally pair-bond,” Arnocky said. “In other words, we form relatively long-term mating relationships that are often characterized by biparental care of offspring. Therefore, we wanted to know whether testosterone also plays a role in mating competition once a male has secured a romantic partner.”

The researchers collected saliva samples from 108 male undergraduates to measure their testosterone levels and had them complete surveys on mate retention and intrasexual competition. They found there was an indirect relationship between testosterone and mate retention behaviors.

“Our results suggested that there is a modest relationship between testosterone and mate-retention, but that this relationship is not direct in nature. Rather, testosterone predicts holding a more competitive attitude toward members of the same sex (intrasexual competition), and it is this characteristic of intrasexual competitiveness that in turn predicts mate retention,” Arnocky told PsyPost.

“Moreover, this relationship seems to be strongest for cost inflicting, rather than benefit provisioning, acts of mate retention.”

Examples of cost-inflicting mate retention behavior include things such as limiting a partner’s social life by monopolizing her time and insulting her to make her feel undeserving of the current relationship.

“Our study was correlational in its design, and so one cannot make any causal assumptions about whether testosterone influences levels of intrasexual competitiveness or mate retention,” Arnocky noted.

“Future research would benefit from administering testosterone to healthy men who are currently in romantic relationships and subsequently assess mate retention in a laboratory setting to better address this important directional issue,” he added.

The study, “Intrasexual competition mediates the relationship between men’s testosterone and mate retention behavior“, was co-authored by Graham Albert, Justin M. Carré, and Triana L. Ortiz.

