Fight/Flight/Freeze and Gender

Gender Differences in Responses to Stress: It Boils Down to a Single Gene: Fight-or-Flight vs Tend-and-Befriend
Psychology Today Online.  Posted Mar 17, 2012

You are walking alone in a dark alley late at night when, all of a sudden, you feel the barrel of a gun pressed to the back of your neck and hear a voice saying: “Give me your wallet or I will kill you.” What do you do? The answer is: it depends on whether you are a man or a woman. If you are a man, you either run away as quick as you can or you turn around and punch the guy in the face. If you are a woman, you try to talk yourself out of the situation: “Are you sure you want to do this?” you ask the robber, or “If you put the gun away, we can talk about the situation and I will see what I can do to help you.”

According to some psychologists, there is basic difference in the way men and women respond to social stress: for men, it’s either “fight or flight” while for women it’s “tend and befriend.” Physiologist Walter Cannon – a pioneer of research on stress – argued in the 1930s that “fight-or-flight” is a universal physiological response to stress shown not only by all humans, but by animals as well.  This response is controlled by the sympathetic nervous system – the part of our nervous system that deals with automatic functions such as breathing. Under stress, this system is activated, increasing heart rate and blood pressure, hastening breathing, and otherwise readying you to face down your enemy or to run. Thousands of studies inspired by Cannon described and documented this response in a variety of species and situations. The vast majority of these studies, however, were conducted with males.

In 2000, UCLA social psychologist Shelley Taylor and her colleagues wrote an influential article in Psychological Review, which Taylor later expanded into a book called The Tending Instinct, to propose that when it comes to stress, women are different from men. Instead of getting ready to fight or to flee, women become more likely to express affiliative social behavior, either to befriend the enemy – if there is an enemy and is causing the stress – or to seek social support from their family members or friends. Physiologically, instead of releasing large amounts of norepinephrine and cortisol into the bloodstream the way men do, Taylor argued that women respond to stress by secreting more endorphins – neurochemical substances that help alleviate pain and make us feel good about social interactions – and oxytocin, a neurohormone that is linked to the motivation to behave in a friendly manner to children or close social partners.

In support of Taylor’s hypothesis, I can tell you from experience that if you put two adult male rhesus monkeys who have never met before in a small cage, they will fight and try to kill each other. In contrast, if you put two females in a cage, they will reduce the tension and awkwardness of the situation by exchanging grooming behavior (grooming is the main form of affiliation in monkeys and is known to cause a release of endorphins and to reduce stress in the receiver – not unlike receiving a body massage from your favorite masseuse).

A new study conducted in Australia suggests that the difference between men and women in their responses to stress may boil down to a single gene. The authors of this study argued that the SRY gene that men have on their Y chromosome – right between the gene for flipping through TV channels with the remote control and the gene for not putting the toilet seat down after peeing – causes their fight-or-flight response, while women use different genetic and physiological mechanisms to deal with stress.

The SRY gene was previously thought to be involved only in the development of male genitalia in the womb, but the proteins produced by this gene have now been found also in the brain and other organs. It turns out that these SRY proteins regulate the secretion of neurotransmitters known as catecholamines, which include norepinephrine, dopamine, and serotonin, and play an important role in neural activity, cardiovascular function, and movement. The SRY gene and its proteins may contribute to the release of large amounts of norepinephrine in the blood stream and the increase in blood pressure and motor activity occurring after stress in men, which in turn, facilitate the expression of the fight-or-flight response. Since women don’t have the SRY gene, their responses to stress are regulated by other genes and other physiological changes involving estrogen hormones and, as previously mentioned, oxytocin and endorphins. These physiological changes, in turn, facilitate the expression of the tend-and-befriend response.

Obviously, women too show increases in catecholamines and in blood pressure after stress. These physiological processes are controlled by multiple genes, with the result that male and female physiology are generally more similar than Australian researchers might think. This is true also for other physiological gender differences, where men differ on average from women but there is overlap in the distribution of the trait. For example, although men have, on average, much more testosterone in their body than women, there are women whose testosterone is as high as, or even higher than men’s testosterone. Recent studies conducted in Australia have shown that when these high-testosterone women respond to stress, particularly stress caused by men such as being held at gunpoint by a guy in a dark alley, they show the unique and highly effective “kick-the-man-in-the-groin” response.

1. Taylor, S. E., et al. (2000). Biobehavioral responses to stress in females: tend-and-befriend, not fight-or-flight. Psychological Review, 107: 411-429.
2. Taylor, S. E. (2002). The Tending Instinct: How Nurturing is Essential to Who We Are and How We Live. New York: Henry Holt.
3. Lee, J., Harley, V. (2012). The male fight-flight response: A result of SRY regulation of catecholamines? BioEssays, published online on March 8^th

ABSTRACTS

Biobehavioral responses to stress in females: Tend-and-befriend, not fight-or-flight.
Taylor, Shelley E., et al.
Psychological Review, Vol 107(3), Jul, 2000. pp. 411-429.
Abstract:
The human stress response has been characterized, both physiologically and behaviorally, as ‘fight-or-flight.’ Although fight-or-flight may characterize the primary physiological responses to stress for both males and females, we propose that, behaviorally, females’ responses are more marked by a pattern of ‘tend-and-befriend.’ Tending involves nurturant activities designed to protect the self and offspring that promote safety and reduce distress; befriending is the creation and maintenance of social networks that may aid in this process. The biobehavioral mechanism that underlies the tend-and-befriend pattern appears to draw on the attachment-caregiving system, and neuroendocrine evidence from animal and human studies suggests that oxytocin, in conjunction with female reproductive hormones and endogenous opioid peptide mechanisms, may be at its core. This previously unexplored stress regulatory system has manifold implications for the study of stress.

Sex differences in cortisol excretion during anticipation of a psychological stressor: Possible support for the tend-and-befriend hypothesis.
Ennis, Michael. Kelly, Kimberly. Lambert, Paul L.
Stress and Health: Journal of the International Society for the Investigation of Stress, Vol 17(4), Jul, 2001. pp. 253-261.
Abstract:
Examined gender differences in the effects of cognitive expectations of anticipated stressors on neuroendocrine responses. Ss were 58 18–44 yr old college students (38 male, 20 female). Hypothalamic-pituitary-adrenal activation was assessed for Ss making a ‘threat appraisal’ vs a ‘challenge appraisal’ of an academic examination. Self-reported anxiety in relation to these variables was also examined. Urinary cortisol was assessed at baseline (at least 1 wk before the examination) and at pre-test (immediately before the examination). Results show there was, contrary to hypothesis, an unexpected sex–time interaction that was particularly robust in Ss making a challenge appraisal. Males in the challenge appraisal group had a significant increase in cortisol excretion from baseline to pre-test, with greater reported anxiety than the threat appraisal group. In contrast, females had a decrease in cortisol excretion that was significant only for the challenge appraisal group, although reported anxiety between the challenge and threat groups was not different. Results may suggest that the female stress response has evolved differently than that of males, or they may reflect sex differences in production of corticosteroid-binding globulin.

Sex differences in behavioral and hormonal response to social threat: Commentary on Taylor et al. (2000).
Geary, David C.. Flinn, Mark V.
Psychological Review, Vol 109(4), Oct, 2002. pp. 745-750.
Abstract:
Taylor and colleagues proposed that women uniquely respond to stressors by tending to children and befriending other women rather than by fighting or fleeing (S. E. Taylor et al., 2000). In this article, the authors expand Taylor et al.’s evolutionary frame and incorporate several unique aspects of human social dynamics. First, humans are characterized by extensive paternal investment, and thus men’s tending is predicted and observed in some stressful contexts. Second, the dynamics of women’s befriending suggest an evolutionary elaboration of the mechanisms that support reciprocal altruism. Third, coalitional male-male competition indicates that men’s befriending is a predicted component of their fight-or-flight response. Finally, men’s tending should result in the evolution of female-female competition over this form of parental investment.

Tend and Befriend Versus Fight or Flight: Gender Differences in Behavioral Response to Stress Among University Students.
Turton, S., Campbell, Carol.
Journal of Applied Biobehavioral Research, Vol 10(4), 2005. pp. 209-232.
Abstract:
Taylor et al. (2000) proposed that female behavioral responses to stress are characterized better as ‘tend and befriend’ than ‘fight or flight.’ Q methodology was adopted to investigate different responses to stress. A Q set of 61 statements was sorted by 40 participants (18 male, 22 female) using principal components factor analysis. Four factors were extracted, accounting for 53.5% of the total variance. The 4 factors corresponded with fight, flight, tend, and befriend stress responses. Females were more likely to portray a tend-and-befriend response to stress.The implications of these findings are discussed in relation to past research that has been conducted with participants, predominantly of a single gender and for future stress research studies.

Tend and Befriend: Biobehavioral Bases of Affiliation Under Stress.
Taylor, Shelley E.
Current Directions in Psychological Science, Vol 15(6), Dec, 2006. pp. 273-277.
Abstract:
In addition to fight-or-flight, humans demonstrate tending and befriending responses to stress–responses underpinned by the hormone oxytocin, by opioids, and by dopaminergic pathways. A working model of affiliation under stress suggests that oxytocin may be a biomarker of social distress that accompanies gaps or problems with social relationships and that may provide an impetus for affiliation. Oxytocin is implicated in the seeking of affiliative contact in response to stress, and, in conjunction with opioids, it also modulates stress responses. Specifically, in conjunction with positive affiliative contacts, oxytocin attenuates psychological and biological stress responses, but in conjunction with hostile and unsupportive contacts, oxytocin may exacerbate psychological and biological stress responses. Although significant paradoxes remain to be resolved, a mechanism that may underlie oxytocin’s relation to the health benefits of social support may be in view.

Gender differences in stress response: Role of developmental and biological determinants
Industrial Psychiatry J. 2011 Jan-Jun; 20(1): 4–10.
Rohit Verma, Yatan Pal Singh Balhara, and Chandra Shekhar Gupta

Cortisol modulates men’s affiliative responses to acute social stress.
Berger, Justus, et al.
Psychoneuroendocrinology, Vol 63, Jan, 2016. pp. 1-9.
Abstract:
The dominant characterization of the physiological and behavioral human stress reaction is the fight-or-flight response. On the other hand, it has been suggested that social affiliation during stressful times (‘tend-and-befriend‘) also represents a common adaptive response to stress, particularly for women. In the current study, we investigate the extent to which menmay also show affiliative responses following acute stress. In addition, we examine a potential neuroendocrine modulator of the hypothesized affiliative response. Eighty male students (forty dyads) were recruited to undergo either the Trier Social Stress Test for Groups (TSST-G) or a non-stressful control situation. Subsequently, participants completed a dyadic interaction task and were then asked to report their feelings of psychological closeness to their interaction partner. Although participants assigned to the stress condition did not differ overall on psychological closeness from participants assigned to the control condition, participants with high cortisol responses to the stressor showed significantly higher ratings of psychological closeness to their interaction partner than participants with low cortisol responses. Our findings suggest that men may form closer temporary bonds following stressful situations that are accompanied by a significant cortisol response. We suggest that the traditional characterization of the male stress response in terms of ‘fight-or-flight’ may be incomplete, and that social affiliation may in fact represent a common, adaptive response to stress in men.

Sex differences in the effects of acute stress on behavior in the ultimatum game.
Youssef, Farid F., et al.
Psychoneuroendocrinology, Vol 96, Oct, 2018. pp. 126-131.
Abstract:
Acute stress affects human decision making. It has been argued that there are systematic sex differences in behavioral responses to acute stress, with males showing a ‘fight or flight’ and females showing a ‘tend and befriend’ response. A ‘tend and befriend’ response would suggest that women become more cooperative under acute stress, while men do not. We investigated the effects of acute stress on social behavior. We induced stress via the Trier Social Stress Test (TSST) and then immediately after measured how participants reacted to offers made in the ultimatum game by a male proposer. We found that female participants were less likely to reject offers under stress (n = 25) vs. no stress (n = 37), p = 0.009, independent of how fair these offers were, cooperative behavior consistent with the ‘tend and befriend’ hypothesis. Male participants when stressed (n = 30) did not show differences in rejections rates compared to the control condition (n = 26), p = 0.41. Our results provide support for a qualitatively different behavioral response to acute stress among men and women.