General Adaptation Syndrome

The physiologist Hans Seyle (1907–1982) studied stress by examining how rats responded to being exposed to stressors such as extreme cold, infection, shock, and excessive exercise. Seyle found that regardless of the source of the stress, the rats experienced the same series of physiological changes as they suffered the prolonged stress. Seyle created the term general adaptation syndromeThe three distinct phases of physiological change that occur in response to long-term stress: alarm, resistance, and exhaustion. to refer to the three distinct phases of physiological change that occur in response to long-term stress: alarm, resistance, and exhaustion (Figure 3.5 "General Adaptation Syndrome").

Figure 3.5 General Adaptation Syndrome

Hans Seyle’s research on the general adaptation syndrome documented the stages of prolonged exposure to stress.

The experience of stress creates both an increase in general arousal in the sympathetic nervous system (SNS) and another, even more complex, system of physiological changes through the HPA axis (Figure 3.6 "HPA Axis"). The HPA axisA physiological response to stress involving interactions among the hypothalamus, the pituitary gland, and the adrenal glands. is a physiological response to stress involving interactions among the hypothalamus, the pituitary gland, and the adrenal glands. The HPA response begins when the hypothalamus secretes hormones that direct the pituitary gland to release the hormone ACTH. The ACTH then directs the adrenal glands to secrete more hormones, including epinephrine, norepinephrine, and cortisolA stress hormone that releases sugars into the blood to help prepare the body to respond to threat., a stress hormone that releases sugars into the blood to help prepare the body to respond to threat(Rodrigues, LeDoux, & Sapolsky, 2009).Rodrigues, S. M., LeDoux, J. E., & Sapolsky, R. M. (2009). The influence of stress hormones on fear circuitry. Annual Review of Neuroscience, 32, 289–313.

Cortisol is frequently referred to as the “stress hormone,” and it is commonly measured by researchers in order to assess the activation of the HPA axis in response to stress. Cortisol is measured by taking a sample of saliva, which is then analyzed to determine cortisol levels. Cortisol increases when people are stressed, for instance, when they are in dancing competitions (Edelstein, Yim, & Quas, 2010),Edelstein, R. S., Yim, I. S., & Quas, J. A. (2010). Narcissism predicts heightened cortisol reactivity to a psychosocial stressor in men. Journal of Research in Personality, 44(5), 565–572. when they are experiencing public shame (Rohleder, Chen, Wolf, & Miller, 2008),Rohleder, N., Chen, E., Wolf, J. M., & Miller, G. E. (2008). The psychobiology of trait shame in young women: Extending the social self-preservation theory. Health Psychology, 27(5), 523–532. and (I’m sure you won’t be surprised) when taking school exams (Preuss, Schoofs, Schlotz, & Wolf, 2010).Preuss, D., Schoofs, D., Schlotz, W., & Wolf, O. T. (2010). The stressed student: Influence of written examinations and oral presentations on salivary cortisol concentrations in university students. Stress: The International Journal on the Biology of Stress, 13(3), 221–229.

Figure 3.6 HPA Axis

Stress activates the HPA axis. The result is the secretion of epinephrine, norepinephrine, and cortisol.

The experience of prolonged stress has a direct negative influence on our physical health because at the same time that stress increases activity in the SNS, it also suppresses important activity in the PNS. When stress is long-term, the HPA axis remains active and the adrenals continue to produce cortisol. This increased cortisol production exhausts the stress mechanism, leading to fatigue and depression.

The HPA reactions to persistent stress lead to a weakening of the immune system, making us more susceptible to a variety of health problems, including colds and other diseases (Cohen & Herbert, 1996; Faulkner & Smith, 2009; Miller, Chen, & Cole, 2009; Uchino, Smith, Holt-Lunstad, Campo, & Reblin, 2007).Cohen, S., & Herbert, T. B. (1996). Health psychology: Psychological factors and physical disease from the perspective of human psychoneuroimmunology. Annual Review of Psychology, 47, 113–142; Faulkner, S., & Smith, A. (2009). A prospective diary study of the role of psychological stress and negative mood in the recurrence of herpes simplex virus (HSV1). Stress and Health: Journal of the International Society for the Investigation of Stress, 25(2), 179–187; Miller, G., Chen, E., & Cole, S. W. (2009). Health psychology: Developing biologically plausible models linking the social world and physical health. Annual Review of Psychology, 60, 501–524; Uchino, B. N., Smith, T. W., Holt-Lunstad, J., Campo, R., & Reblin, M. (2007). Stress and illness. In J. T. Cacioppo, L. G. Tassinary, & G. G. Berntson (Eds.), Handbook of psychophysiology (3rd ed., pp. 608–632). New York, NY: Cambridge University Press. Stress also damages our DNA, making us less likely to be able to repair wounds and respond to the genetic mutations that cause disease (Epel et al., 2006).Epel, E., Lin, J., Wilhelm, F., Wolkowitz, O., Cawthon, R., Adler, N.,…Blackburn, E. H. (2006). Cell aging in relation to stress arousal and cardiovascular disease risk factors. Psychoneuroendocrinology, 31(3), 277–287. As a result, wounds heal more slowly when we are under stress, and we are more likely to get cancer (Kiecolt-Glaser, McGuire, Robles, & Glaser, 2002; Wells, 2006).Kiecolt-Glaser, J. K., McGuire, L., Robles, T. F., & Glaser, R. (2002). Psychoneuroimmunology: Psychological influences on immune function and health. Journal of Consulting and Clinical Psychology, 70(3), 537–547; Wells, W. (2006). How chronic stress exacerbates cancer. Journal of Cell Biology, 174(4), 476.

Sheldon Cohen and colleagues (Cohen et al., 1998)Cohen, S., Frank, E., Doyle, W. J., Skoner, D. P., Rabin, B. S., & Gwaltney, J. M. Jr. (1998). Types of stressors that increase susceptibility to the common cold in adults. Health Psychology, 17, 214–23. demonstrated experimentally that repeated exposure to threats and stress can increase susceptibility to the common cold virus, revealing the causal link between psychological stress and actual susceptibility to disease. To begin, the researchers had adult volunteers fill out several questionnaires about the stressful experiences in their lives. Then the researchers administered nose drops into each participant’s nose. The control group (the lucky ones!) received a placebo saline solution; the experimental group received a solution containing a cold virus. Over the next week, the participants were examined daily by a nurse. None of the control group participants got a cold. But of those exposed to the cold virus, 82% did get a cold. Furthermore, within this condition, those participants who reported enduring long-term stressors—particularly those who felt that they were underemployed or who had enduring interpersonal difficulties with family or friends—were significantly more likely to catch colds than those who had only short-term stress.

Chronic stress is also a major contributor to heart disease. Although heart disease is caused in part by genetic factors, as well as by high blood pressure, high cholesterol, and cigarette smoking, it is also caused by stress (Krantz & McCeney, 2002).Krantz, D. S., & McCeney, M. K. (2002). Effects of psychological and social factors on organic disease: A critical assessment of research on coronary heart disease. Annual Review of Psychology, 53, 341–369. Long-term stress creates two opposite effects on the coronary system. Stress increases cardiac output (i.e., the heart pumps more blood) at the same time that it reduces the ability of the blood vessels to conduct blood through the arteries, as the increase in levels of cortisol leads to a buildup of plaque on artery walls (Dekker et al., 2008).Dekker, M., Koper, J., van Aken, M., Pols, H., Hofman, A., de Jong, F.,…Tiemeier, H. (2008). Salivary cortisol is related to atherosclerosis of carotid arteries. Journal of Clinical Endocrinology and Metabolism, 93(10), 3741. The combination of increased blood flow and arterial constriction leads to increased blood pressure (hypertension), which can damage the heart muscle, leading to heart attack and death.

Sources of Stress

The stressors for Seyle’s rats included electric shock and exposure to cold. Although these are probably not on your top-10 list of most common stressors, the stress that we experience in our everyday social interactions can also be taxing. Thomas Holmes and Richard Rahe (1967)Holmes, T. H., & Rahe, R. H. (1967). The social readjustment rating scale. Journal of Psychosomatic Research, 11, 213–218. developed a measure of some everyday life events that might lead to stress, and you can assess your own likely stress level by completing the measure in Table 3.1 "The Holmes and Rahe Stress Scale" and calculating your stress level by looking at Table 3.2 "Interpretation of the Holmes and Rahe Stress Scale". You might want to pay particular attention to this score because it can predict the likelihood that you will get sick. Rahe and his colleagues (Rahe, Mahan, Arthur, & Gunderson, 1970)Rahe, R. H., Mahan, J., Arthur, R. J., & Gunderson, E. K. E. (1970). The epidemiology of illness in naval environments: I. Illness types, distribution, severities and relationships to life change. Military Medicine, 135, 443–452. asked 2,500 members of the military to complete the rating scale and then assessed the health records of the soldiers over the following 6 months. The results were clear: The higher the scale score, the more likely the soldier was to end up in the hospital.

Although some of the items on the Holmes and Rahe scale are major, you can see that even minor stressors add to the total score. Our everyday interactions with the environment that are essentially negative, known as daily hasslesOur everyday interactions with the environment that are essentially negative., can also create stress, as well as poorer health outcomes (Hutchinson & Williams, 2007).Hutchinson, J. G., & Williams, P. G. (2007). Neuroticism, daily hassles, and depressive symptoms: An examination of moderating and mediating effects. Personality and Individual Differences, 42(7), 1367–1378. Events that may seem rather trivial altogether, such as having an argument with a friend or getting cut off by another car in rush-hour traffic, can produce stress (Fiksenbaum, Greenglass, & Eaton, 2006).Fiksenbaum, L. M., Greenglass, E. R., & Eaton, J. (2006). Perceived social support, hassles, and coping among the elderly. Journal of Applied Gerontology, 25(1), 17–30. Glaser (1985)Glaser, R. (1985). Stress-related impairments in cellular immunity. Psychiatry Research, 16(3), 233–239. found that medical students who were tested during, rather than several weeks before, their school examination periods showed lower immune system functioning. Other research has found that even more minor stressors, such as having to do math problems during an experimental session, can compromise the immune system (Cacioppo et al., 1998).Cacioppo, J. T., Berntson, G. G., Malarkey, W. B., Kiecolt-Glaser, J. K., Sheridan, J. F., Poehlmann, K. M.,…Glaser, R. (1998). Autonomic, neuroendocrine, and immune responses to psychological stress: The reactivity hypothesis. In Annals of the New York Academy of Sciences: Neuroimmunomodulation: Molecular aspects, integrative systems, and clinical advances (Vol. 840, pp. 664–673). New York, NY: New York Academy of Sciences.

Responses to Stress

Not all people experience and respond to stress in the same way, and these differences can be important. The cardiologists Meyer Friedman and R. H. Rosenman (1974)Friedman, M., & Rosenman, R. H. (1974). Type A behavior and your heart. New York, NY: Knopf. were among the first to study the link between stress and heart disease. In their research, they noticed that even though the partners in married couples often had similar lifestyles, diet, and exercise patterns, the husbands nevertheless generally had more heart disease than did the wives. As they tried to explain the difference, they focused on the personality characteristics of the partners, finding that the husbands were more likely than the wives to respond to stressors with negative emotions and hostility.

Recent research has shown that the strongest predictor of a physiological stress response from daily hassles is the amount of negative emotion that they evoke. People who experience strong negative emotions as a result of everyday hassles and who respond to stress with hostility experience more negative health outcomes than do those who react in a less negative way (McIntyre, Korn, & Matsuo, 2008; Suls & Bunde, 2005).McIntyre, K., Korn, J., & Matsuo, H. (2008). Sweating the small stuff: How different types of hassles result in the experience of stress. Stress & Health: Journal of the International Society for the Investigation of Stress, 24(5), 383–392. doi:10.1002/smi.1190; Suls, J., & Bunde, J. (2005). Anger, anxiety, and depression as risk factors for cardiovascular disease: The problems and implications of overlapping affective dispositions. Psychological Bulletin, 131(2), 260–300. Williams and his colleagues (2001)Williams, R. B. (2001). Hostility: Effects on health and the potential for successful behavioral approaches to prevention and treatment. In A. Baum, T. A. Revenson, & J. E. Singer (Eds.), Handbook of health psychology. Mahwah, NJ: Lawrence Erlbaum Associates.found that people who scored high on measures of anger were three times more likely to suffer from heart attacks in comparison with those who scored lower on anger.

On average, men are more likely than are women to respond to stress by activating the fight-or-flight responseAn emotional and behavioral reaction to stress that increases the readiness for action., which is an emotional and behavioral reaction to stress that increases the readiness for action. The arousal that men experience when they are stressed leads them to either go on the attack, in an aggressive or revenging way, or else retreat as quickly as they can to safety from the stressor. The fight-or-flight response allows men to control the source of the stress if they think they can do so, or if that is not possible, it allows them to save face by leaving the situation. The fight-or-flight response is triggered in men by the activation of the HPA axis.

Women, on the other hand, are less likely to take a fight-or-flight response to stress. Rather, they are more likely to take a tend-and-befriend response (Taylor et al., 2000).Taylor, S. E., Klein, L. C., Lewis, B. P., Gruenewald, T. L., Gurung, R. A. R., & Updegraff, J. A. (2000). Biobehavioral responses to stress in females: Tend-and-befriend, not fight-or-flight. Psychological Review, 107(3), 411–429. The tend-and-befriend responseA behavioral reaction to stress that involves activities designed to create social networks that provide protection from threats. is a behavioral reaction to stress that involves activities designed to create social networks that provide protection from threats. This approach is also self-protective because it allows the individual to talk to others about her concerns as well as to exchange resources, such as child care. The tend-and-befriend response is triggered in women by the release of the hormone oxytocin, which promotes affiliation. Overall, the tend-and-befriend response is healthier than the flight-or-flight response because it does not produce the elevated levels of arousal related to the HPA, including the negative results that accompany increased levels of cortisol. This may help explain why women, on average, have less heart disease and live longer than men.

The experience of long-term stress—and its potential negative impact on our physical and mental health—represents one example of the powerful influence of the social situation in our everyday lives. These findings represent social psychological principles in action: Our affect, cognition, and behavior are influenced in profound ways by the events that occur to us, and particularly by the people around us. Furthermore, the observed gender differences in response to stress demonstrate another example of the operation of the basic principles of social psychology: Men usually respond to stress by focusing on self-concern (fight or flight) whereas women are more likely to respond by focusing on other-concern (tend-and-befriend).