Conflict in marriage can trigger testosterone surges in men, but not women, and these divergent hormonal reactions may highlight why marital arguments can escalate and cause chronic relationship problems.

That’s according to first-of-its-kind research from Florida State University’s Anastasia Makhanova, a doctoral student in FSU’s Department of Psychology.

The study, published in the journal Hormones and Behavior, found a man typically experiences a testosterone spike when he thinks his wife is opposing him in some way, and his response can lead to continuing friction. Existing research suggests this physiological response can create a pattern of negative behaviors in all arguments that hurt the relationship over time.

“If a man argued with a spouse and he perceived her to be challenging him by blaming or rejecting him, then he was more likely in our study to experience a surge in testosterone,” Makhanova said. “It was all about perceptions. Interestingly, a man’s physiological response was not based on what his wife was actually doing — it was based on what he thought his wife was doing.”

The groundbreaking study focused on conflicts between people in close relationships. Previous research has primarily measured testosterone responses during sports competitions.

Makhanova brought 50 newlywed couples, married less than three months, into an FSU laboratory where they chose four “hot-button” marital issues to discuss. Each couple was left alone in a room with video cameras and given eight minutes to work out each problem.

Some couples tried to resolve the issues as a team and were able to stay calm. But most of the couples descended into common, angrier behaviors, such as blaming their partners, getting hostile, using sarcasm, denying responsibility or flat out rejecting their point of view. Many demanded immediate change.

“If a surge of testosterone leads a spouse to be more aggressive or competitive, then a couple might fall into a negative, back-and-forth pattern of communication where they hurl more insults at each other and retaliate,” Makhanova said. “Ultimately, they’re not resolving the problem.”

That kind of unresolved pattern may have a toxic impact on a marriage. Then every argument tumbles into an example of “negative reciprocity” — basically a downward spiral of aggression and bitterness.

The FSU research documented that heated arguments provoked testosterone surges in many men, while women — who produce smaller quantities of testosterone — did not experience the same effect.

Makhanova said that difference in men and women was notable.

“Our research supports the idea that men and women probably feel equally upset and challenged when their partner behaves this way, but in men we’re picking up this difference in testosterone,” Makhanova said. “The fact that women did not experience the same testosterone response is consistent with existing evidence that men and women sometimes experience different physiological responses to stressors.”

One stress response for women, according to previous research known as the Tend-and-Befriend Hypothesis, pointed to a release of the calming hormone oxytocin. It can encourage more social bonding, so a woman might reach out to friends following a marital conflict.

Complicating things further, Makhanova said, when arguments produce a surge of testosterone — also associated with sexual desire — the conflict may spark the scientifically valid concept of testosterone-fueled “makeup sex.”

“Some interesting previous research has found the brain is not good at understanding why certain physiological processes are happening, including sudden increases in testosterone, and so that arousal can go different ways,” Makhanova said. “No researcher has measured whether a testosterone spike during marital arguments will lead to makeup sex, but that would be a very good follow-up study.”

Makhanova wants to expand current research on the consequences of physiological reactions and how they might reinforce future patterns of behavior, especially negative ones such as blaming and rejecting.

She hopes to help couples better understand how the mind and body work together, so spouses can use that information to handle arguments with positive strategies.

“Conflicts are very important for couples to resolve, and this gives us more tools to figure out why certain couples have a harder time navigating their problems,” Makhanova said. “If people understand they have certain physical reactions when they think they’re being challenged, and if they know they might be misinterpreting what their partner is saying, then maybe that awareness can help them pause, reflect and channel that energy into another activity and end up with a clearer head.”

Department of Psychology faculty members James McNulty, Lisa Eckel, Jon Maner and senior researcher Larissa Nikonova contributed to the study.