What makes some couples bounce back from stress so quickly? New clues emerge from cortisol and partner behavior

Sadie Harley

Scientific Editor

Meet our editorial team
Behind our editorial process

Robert Egan

Associate Editor

Meet our editorial team
Behind our editorial process
Editors' notes

This article has been reviewed according to Science X's editorial process and policies. Editors have highlighted the following attributes while ensuring the content's credibility:

fact-checked

peer-reviewed publication

trusted source

proofread

The GIST
Add as preferred source

How partners respond to stress may be as important as the stress itself, according to two new Canadian studies of lesbian, gay, bisexual, transgender and nonbinary couples. Known collectively as sexual and gender diverse (SGD) couples, these partners recover more efficiently from acute stress and display more engaged and coordinated support behaviors than cisgender heterosexual couples, the Université de Montréal studies found.

Published separately in Biopsychosocial Science and Medicine and Psychoneuroendocrinology, the studies provide one of the most detailed examinations to date of stress as a two-fold biological process, the authors say.

Acute stress activates the hypothalamic-pituitary-adrenal (HPA) axis, releasing the "fight-or-flight" stress hormone cortisol to mobilize energy. While this response is adaptive, prolonged or poorly regulated recovery is linked to adverse physical and mental health outcomes.

For the studies, couples were put in a room together for two hours; one partner was given a series of standardized questions designed to get their cortisol to kick in, while the other played a supportive role.

Seven repeated saliva samples were then taken from each participant, allowing researchers to track cortisol changes in both partners simultaneously. This approach captures stress physiology at the level of the couple rather than the individual.

Higher reactivity, higher cortisol

The first study, in Biopsychosocial Science and Medicine, followed 101 couples (42 SGD) and examined cortisol responses in both stressed and supporting partners. Individuals assigned male at birth showed higher cortisol reactivity following stress exposure. Among supporting partners, those assigned female at birth showed higher cortisol during recovery, suggesting that providing support is itself physiologically activating.

Most importantly, SGD couples showed significantly lower cortisol levels during recovery compared with cisgender heterosexual couples, an effect that remained after adjusting for relationship satisfaction and duration. This pattern was primarily driven by supporting partners in SGD couples, whose cortisol levels remained lower during recovery.

"These results suggest that the ways SGD couples support each other are not only psychologically meaningful, but biologically measurable," said Silke Jacmin-Park, a doctoral candidate in clinical psychology and the study's lead author. "Support within these relationships appears to shape how efficiently the body recovers from stress."

Robert-Paul Juster, an UdeM associate professor of psychiatry and addiction and the study's senior author, added, "Much of the scientific literature to date has focused on the health risks of minority stress, and those risks are well-known. What our work shows is that SGD couples may also develop distinctive strengths in co-regulation and mutual support that have direct physiological consequences."

Specific support behaviors explain recovery differences

The second study, in Psychoneuroendocrinology, examined a larger final sample of 118 couples (51 SGD) and identified the behavioral mechanisms underlying these physiological differences using video recordings of discussions their partners had before and after they were exposed to stress.

Using trained observers and a standardized behavioral system, researchers coded real-time interactions across seven positive support dimensions: emotional expression, attentiveness, validation, problem description, suggestions for change, behavioral engagement, and interactional synchrony, a global measure of dyadic (two-fold) coordination.

Collectively among all couples, supportive behaviors such as attentiveness and engagement predicted faster cortisol recovery in the stressed partner. Interestingly, SGD partners showed greater engagement and interactional synchrony during stress discussions, reflecting greater attunement.

The type of couple further shaped these associations. In SGD couples, emotional expression by the stressed partner was linked to faster recovery. In cisgender heterosexual couples, reduced self-expression paired with high attentiveness was associated with slower recovery.

"These findings are important because they identify concrete, modifiable behaviors linked to physiological recovery," said Sophie Bergeron, the second study's senior author. "Active engagement, validation and emotional expression appear to support faster stress regulation at the biological level."

Co-author Beáta Bőthe, a UdeM assistant professor of psychology, added, "By combining observational data with hormonal measures and dyadic modeling, we are able to move beyond subjective experiences and capture how couples actually behave under stress, and how this synergy maps onto biology."

Discover the latest in science, tech, and space with over 100,000 subscribers who rely on Phys.org for daily insights. Sign up for our free newsletter and get updates on breakthroughs, innovations, and research that matter—daily or weekly.

Subscribe

Why might SGD couples show these patterns?

The authors suggest that experiences of stigma and discrimination may foster stronger reliance on close relationships and more intentional support systems, including "chosen family" dynamics. Within romantic partnerships, this may translate into greater emotional attunement, communication and mutual care.

Shared experiences of marginalization may also enhance empathy and coordination during stress, contributing to both behavioral synchrony and more efficient physiological recovery, the co-authors believe.

Importantly, all couples in the studies showed strong cortisol increases under stress. The difference from cisgender heterosexual couples lies in how efficiently and collaboratively they recovered.

Together, these studies advance understanding of stress as a dyadic biological process, demonstrating that partner interactions shape physiological recovery in measurable ways, the co-authors say.

They also identify specific, modifiable behaviors: emotional expression, validation, attentiveness and engagement all appear to support faster stress recovery, they note. For SGD couples in particular, the findings suggest that encouraging open emotional expression during stress may be especially beneficial for physiological regulation.

This work was carried out by members from the Interdisciplinary Research Center on Intimate Relationship Problems & Sexual Abuse (CRIPCAS). Future research by this team will expand sample diversity and further investigate mechanisms such as intimacy, intersectionality and multiple marginalization processes.

Publication details

Silke Jacmin-Park et al, Cortisol Recovery Differs Among Sexual and Gender Diverse Couples Compared with Cisgender Heterosexual Couples, Biopsychosocial Science and Medicine (2026). DOI: 10.1097/psy.0000000000001485

Observed positive support and cortisol reactivity/recovery among heterosexual cisgender and sexually and gender diverse couples. Psychoneuroendocrinology. DOI: 10.1016/j.psyneuen.2026.107864

Journal information: Psychoneuroendocrinology

Provided by University of Montreal