Why this question matters

Women and men share the same basic stress system, but women's stress responses were studied far less for decades. Much of what we learned about stress came from men and male animals.

Until the 1990s, many clinical studies enrolled mostly men. Women's hormonal cycles were often seen as "noise" that complicated the data. In the US, the National Institutes of Health only required women in clinical trials from 1993. It only required both sexes in animal research from 2016.

The gap is closing. There is now a large body of research on sex differences in stress, trauma, anxiety and pain. Some areas are still thin, such as how stress changes across the menstrual cycle and through menopause.

The shared foundation: fight-or-flight

Every human body, female or male, reacts to threat through the same two systems. Women do not have a separate nervous system.

• The fast system (sympathetic nervous system) Within seconds, adrenaline raises your heart rate, sharpens your attention and sends energy to your muscles. This is the classic fight-or-flight response.
• The slower system (HPA axis) Over minutes, your brain signals your adrenal glands to release cortisol. Cortisol keeps energy available and helps the body recover once the threat has passed.

The differences described below are variations on this shared system. They are average tendencies, and individual women and men overlap a lot.

What differs, on average

Research finds some real average differences between women's and men's stress responses. Most are about hormones and about which situations feel most threatening.

Hormones change the dial. Estrogen and oxytocin influence how strongly the cortisol system and the fast system respond. Because these hormones shift, a woman's stress response can differ across:

• the phases of her menstrual cycle
• use of hormonal contraception
• pregnancy and the months after birth
• perimenopause and menopause

Different stressors hit harder. I In one well-known study, men showed bigger cortisol responses to achievement challenges, like tests and performance. Women showed bigger responses to social rejection (Stroud, Salovey & Epel, 2002). In lab tasks such as public speaking, men often show larger cortisol spikes.

Long-term outcomes differ. Women develop PTSD after trauma at about twice the rate of men, and anxiety and depression are also more common in women. The reasons are mixed: biology, the types of trauma women experience more often, and social factors all play a part.

Tend-and-befriend: a second pattern

In 2000, psychologist Shelley Taylor and colleagues proposed that women under stress often tend and befriend.In plain terms, they protect the people they care for and reach out to others for support.

Taylor linked this pattern to oxytocin and to the body's natural opioids. These chemicals are released under stress and encourage bonding and seeking comfort. Estrogen appears to strengthen oxytocin's effects.

Two things are easy to miss in popular retellings:

• It adds to fight-or-flight; it doesn't replace it. Women still get the adrenaline and cortisol response. Tend-and-befriend describes what they more often do with it..
• The evidence has limits. Much of it came from animal studies or from Western women. That makes it hard to tell biology apart from upbringing. Taylor herself said socialization and culture probably shape the pattern too.

What about polyvagal theory?

Polyvagal theory is a popular, helpful way to describe stress states, but it is scientifically contested and has not been tested for sex differences.

Neuroscientist Stephen Porges proposed that the vagus nerve supports three states, in a fixed order:

• Safe and social ("ventral vagal"): calm, connected, able to engage with others.
• Fight-or-flight (sympathetic): mobilized to act against a threat.
• Shutdown or freeze ("dorsal vagal"): collapse when a threat feels inescapable.

The science is debated. In 2023, Paul Grossman argued that the theory's five core premises are likely wrong, including its evolutionary story. Porges and his supporters have replied. Many clinicians now treat it as a useful map for talking about stress, not as established physiology.

What we know about women's vagal activity. No study has tested the three-state model separately in women and men. Research on heart rate variability (HRV), a common measure of vagal activity, shows two things:

• At rest, women on average show higher vagal activity than men (Koenig & Thayer, 2016).
• During social stress tests in the lab, women's calming vagal activity drops more than men's (meta-analysis, 2020).

Polyvagal ideas overlap with tend-and-befriend. Both involve oxytocin and the idea that connection helps us calm down. Still, claims such as "women are more ventral vagal" go beyond the evidence.

Biology or learned? The role of society

Some of these differences may be learned, shaped by the roles and status women have held. Most researchers now see biology and social experience as intertwined rather than competing.

Social role theory. Psychologists Alice Eagly and Wendy Wood argue that many average sex differences come from the roles men and women have historically filled. Women more often held caregiving roles, with less power and status. People adapt to the roles they are given, and each generation learns what is expected of it. From this view, reaching out to others under stress is a sensible strategy for someone with more caring duties and less power to fight back.

Separating sex from gender. Newer studies measure biological sex and gender roles separately. "Gender roles" means how strongly someone identifies with traits and roles seen as masculine or feminine.

• A 2019 review by Robert-Paul Juster found that gender, sexual orientation and social context predict stress hormones beyond biological sex.
• A 2021 study found that people's gender-role orientation, not only their sex, was linked to how their cortisol adapted to repeated social stress.
• Studies in 2025 and 2026 linked gender-role self-concept to stress reactions, both in lab public-speaking tests and in everyday life.

The stressor finding above fits this picture too. Men react most to achievement threats and women to rejection. These match what each gender has traditionally been taught to value most.

Your biology is not fixed

The roles we play, our social status and long-term stress all measurably change hormones and the brain. So even a "biological" difference measured today may partly reflect a lifetime of experience.

• Roles change hormones. n one experiment, women acted out a powerful "boss" role, firing an employee. Their testosterone rose, whatever style they used (van Anders et al., 2015). In another study, men's testosterone dropped when they became fathers, most of all in those who did the most hands-on childcare (Gettler et al., 2011).
• Status changes the body. Researchers moved female rhesus monkeys up or down their social hierarchy. Low status changed their immune genes and raised inflammation. When their rank improved, most of those changes reversed (Snyder-Mackler et al., 2016).
• Chronic stress reshapes the brain. Neuroscientist Bruce McEwen showed that long-term stress changes brain areas involved in memory, fear and self-control. Those changes can partly reverse when conditions improve.

One caution: no study has directly proven that today's female–male differences come from a lifetime of gender roles. That would require following people from birth or randomly assigning roles, which is impossible. What the evidence does show is that our stress biology responds to how we live.

What this means for you

Your stress response is shaped by your hormones, your history and the roles you live in, and it can change.

1. Notice your own pattern. Do you tend to fight, withdraw, freeze, or reach out and care for others? None of these is wrong. Knowing your pattern gives you more choice.
2. Track your cycle, if you have one. Stress may feel different at different points in your cycle, with contraception, or around menopause. A simple diary can show your own rhythm.
3. Use connection as a resource. Seeking support under stress is a well-documented, healthy response, not a weakness.
4. Question "that's just how women are." Many differences are average tendencies shaped by roles and status. Taking on new roles, such as leadership, can shift how your body responds.
5. Be careful with oversimplified claims. Be wary of any source that says women need a completely different set of rules for their nervous system. The science is more nuanced, and more hopeful.

This paper is educational and not medical advice. If stress, anxiety or trauma symptoms affect your daily life, speak to a qualified professional.

To read

• Taylor, S. E., i in. (2000). Biobehavioral responses to stress in females: Tend-and-befriend, not fight-or-flight. Psychological Review. Omówienie
• Eagly, A. H., i Wood, W. Social role theory of sex differences. Wiley
• Stroud, L. R., Salovey, P., i Epel, E. S. (2002). Sex differences in stress responses: Social rejection versus achievement stress. Biological Psychiatry.
• Juster, R.-P., i in. (2019). Sex × Gender and Sexual Orientation in Relation to Stress Hormones and Allostatic Load.
• Gender roles are related to cortisol habituation to repeated social evaluative stressors in adults (2021). Stress.
• The role of sex and gender role self-concept in stress reactivity: Evidence from the Trier Social Stress Test (2025). Psychoneuroendocrinology.
• The link between the gender role self-concept and psychobiological stress in everyday life (2026). Scientific Reports.
• van Anders, S. M., Steiger, J., i Goldey, K. L. (2015). Effects of gendered behavior on testosterone in women and men. PNAS.
• Gettler, L. T., i in. (2011). Longitudinal evidence that fatherhood decreases testosterone in human males. PNAS.
• Snyder-Mackler, N., i in. (2016). Social status alters immune regulation and response to infection in macaques. Science.
• McEwen, B. S. (2017). Neurobiological and Systemic Effects of Chronic Stress. Chronic Stress.
• McEwen, B. S. (2012). Brain on stress: How the social environment gets under the skin. PNAS.

• Grossman, P. (2023). Fundamental challenges and likely refutations of the five basic premises of the polyvagal theory. Biological Psychology.
• Koenig, J., i Thayer, J. F. (2016). Sex differences in healthy human heart rate variability: A meta-analysis. Neuroscience & Biobehavioral Reviews.
• Quantitative meta-analysis of heart rate variability finds reduced parasympathetic cardiac tone in women compared to men during laboratory-based social stress (2020). Neuroscience & Biobehavioral Reviews.