In this chapter we'll be considering health psychologyhealth psychologyThe field studying how psychological factors, behavior, and social context affect physical health and illness.; the study of how psychological factors influence health, illness, and recovery. This will include attempting to uncover the etiology, or the origin or causes, of illness (aetiology if you prefer the British spelling). This is no easy feat and answers won't be clear, as many psychological factors are hard to measure precisely. As a result, we'll frequently see how certain factors (such as stressstressThe process by which we perceive and respond to events we appraise as threatening or demanding.) increase or decrease risk of an illness, though we can't say they directly cause the illness.

A closely related area of study is epidemiology, which refers to studying the frequency, distribution, and causes of illness. We need to be careful because this is an area in which we can't readily rely on experimentation when it comes to risk factors for most diseases and this limits our ability to draw conclusions about causality. Obviously we can't go around exposing participants to potentially harmful stimuli to see if they develop ulcers, cancer, or heart disease. Instead, we often have to rely on retrospective studies. These studies look into the past of a person who has already been diagnosed with a particular illness. It's far easier to find people who have ulcers and then find out about their pasts than it is to measure people now and then wait for some of them to get ulcers later. This can create a problem for stress research, because once people have an illness they may have a tendency to misrepresent their previous levels of stress (I must have been really stressed, after all, now I've got all these damn ulcers).

Another problem here is that if we measure many factors and many health outcomes, relationships may appear which are purely coincidental. This can be a problem for conclusions about mortality (which has many possible causes and can't be replicated in a particular patient) so we should be careful when considering interventions that claim to increase or decrease longevity. If several elderly patients in a study die this can drastically change the apparent longevity of the groups, even if the causes of these deaths were unrelated. This may also explain why we often see epidemiological studies with opposing conclusions (Is red wine good or bad? What about coffee? Or eggs?)

Occasionally we have prospective studies, which collect data from a large number of healthy people and then track who gets diagnosed with which diseases later. By following participants over time (known as longitudinal research), researchers can see how illnesses develop and how risk factors change throughout a person's life. Unfortunately, these types of studies are rather rare. This is in part because we've gotten so good at beating infections that most deadly illnesses today are those that accumulate slowly over the course of decades (such as heart disease, cancer, diabetes, etc) meaning that longitudinal studies are incredibly time-consuming and prohibitively expensive to conduct.

Walter Cannon (whose name you may recall from the Cannon-Bard Theory of Emotion) investigated reports of “voodoo death” in traditional cultures around the world. In these cases, a shaman or community leader placed a curse on an individual, who subsequently died. Cannon suggested that this was the result of over-activation of the sympathetic nervous system, causing the victim to die from the stress and anxiety of being cursed. It's difficult to say for sure that stress is the cause of voodoo death (also referred to as “psychophysiological death” to avoid cultural insensitivity), as a shaman could curse a person who was already ill, use poison (ensuring success and encouraging others to believe), or it could be the case that after being cursed the person is shunned from society, leading to dehydration and starvation.

Can our beliefs really cause us to become sick? You might think of psychogenic illnesses, which are “illnesses originating from the mind”. We have to be careful because there have been illnesses considered to be psychogenic until the discovery of a new virus, bacterium, hormone, or receptor suddenly makes them “legitimate” and suspicion is no longer cast on the patient's mind. We could also consider cases of psychosomatic illness, which is when symptoms arise from thoughts or beliefs about illness. This doesn't necessarily indicate that the illness is caused by psychological factors (it may still have an underlying biological cause) but that symptoms are expressed or worsened by psychological factors, such as stress increasing the severity of asthma attacks.

In this chapter we'll see how psychological factors like stress can influence the immune systemimmune systemThe body's defense system against pathogens — chronic stress suppresses immune function.'s ability to function, a field known as psychoneuroimmunologypsychoneuroimmunologyThe study of how psychological states affect the nervous system and immune function.. This field looks at the relationships between stress, psychological factors, immune function, and health.

You're undoubtedly familiar with the concept of stress, but like many psychological variables we've seen, you may find it difficult to come up with a precise definition. What exactly is stress and how can we go about measuring it?

Walter Cannon coined the term “fight or flight response” to consider how we react to threats in the environment (you may also recall that a “freeze” response has since been added). Cannon was one of the first researchers to use the term “stress” when referring to something that evoked this response. The term stress was used frequently by Hans Selye (who we'll learn more about later), though his use was criticized because the same word was used for both cause and effect (stress causes stress).

To clarify things a bit, Selye introduced the term stressorstressorAny event or situation that causes stress. to refer more specifically to something that causes a stress response. So we can say that a stressor is something that is a threat to our safety or something that places demands on our resources. This could be as obvious as a bear chasing us through the woods or as subtle as tinges of nervousness before a first date.

The stress response is our physiological reaction to stressors, and involves activation of the sympathetic nervous system. As we'll see throughout this chapter, this response is well-suited for dealing with some stressors but not so great for others.

Despite these more specific labels, the general term stress is still used quite frequently. Thinking in terms of stressors and how we respond to them means that stress can refer to our physiological and psychological response to stressors, which can originate from the environment or from within our own minds. Now let's look at these two aspects of stress in more detail.

We can understand emotions and personality traits by comparing them rather than carefully defining them and the same can be done with stressors. Thomas Holmes and Richard Rahe (1967) created the Social Readjustment Rating Scale to compare how stressful different life events are perceived to be. On the very top end of this scale are incredibly traumatic events such as being raped, being diagnosed with a terminal illness, or dealing with the death of a close friend or family member. Below these highly stressful events are mid-level stressors such as getting into a physical fight, making a speech, experiencing sleep deprivation, or getting a new job or moving to a new city. At the bottom end, we have minor stressors such as being sick with a common cold, participating in an athletic event, going on a first date, or fighting traffic in your morning commute.

Individual differences also play a role in determining whether something is a stressor. Our level of stress depends on our interpretation of the situation. A particular stimulus might be considered stressful to some people and not-so-stressful to others. The same traffic jam may frustrate one person (who is running late for a crucial meeting) but not bother the driver next to her in the slightest.

We can also consider the role that frequency plays in stress. While major stressors are hopefully infrequent, some minor stressors become daily hassles which occur repeatedly or continuously. These chronic stressors can be particularly problematic when they evoke a stress response day after day, without giving the body a chance to recover. A related type of stressor is an environmental stressor, which refers to something in the environment that continuously evokes a stress reaction. Children attending schools located on flight paths have been shown to have higher blood pressure and lower resilienceresilienceThe ability to recover from adversity and maintain positive adaptation under difficult conditions. than their peers in quieter learning environments. Crowding is another environmental stressor and people show a physiological response to cramped living conditions or being packed like sardines in a subway car.

While Cannon's expression “fight or flight” is still frequently used, there's growing recognition of other responses to threats and Shelley Taylor has proposed possible gender differences in the stress response. Women may be less likely to “fight” or act aggressively in the face of a threat (though they certainly can do so), and Taylor's research has focused on a tend and befriend response. This refers to a greater focus on relationships, empathy, and group cohesion in the face of a threat. This response has been linked to the release of the hormone oxytocin in response to threats, which occurs for both genders but may be stronger in females. Research by Mara Mather and colleagues in 2010 found that women showed greater activation of brain areas associated with face recognition and empathy when stressed. For now, we'll focus on the “fight or flight” aspect of the stress response and look closer at the roles of brain regions, neurotransmitters, and hormones in regulating this process during and after exposure to a stressor.

The activation of the sympathetic nervous system occurs along the HPA axis, which refers to the Hypothalamus, Pituitary gland, and Adrenal glands. While the pituitary gland is referred to as the “master gland”, the brain is the true master and the hypothalamus releases hormones that tell the pituitary what to do. In the case of the stress response, the hypothalamus releases a hormone known as CRH (corticotropin releasing hormone). CRH tells the pituitary gland to release ACTH (adrenocorticotropic hormone), which travels in the bloodstream to the adrenal glands, which release the catecholamines (pronounced cat-a-coal-a-means) epinephrine and norepinephrine, which activate the sympathetic nervous system. It's easier to remember that epinephrine and norepinephrine are released by the adrenal glands if you remember their British names; adrenaline and noradrenaline.

The adrenal glands also release a group of steroid hormones known as glucocorticoids. As we'll see, these glucocorticoids (such as cortisolcortisolThe primary stress hormone released by the adrenal cortex — mobilizes energy but impairs immune function when chronically elevated.) play a fundamental role in the stress response and are one of the keys for understanding how stress can negatively affect the body. These hormones help to mobilize energy resources (increasing glucose in the bloodstream) and prepare for possible injury by reducing inflammation. The stress response emphasizes immediate needs so processes that don't help you survive right now are put aside. Digestion, growth, reproduction and sex drive (now is not the time to look for a mate!) are for long-term projects that won't matter if the current crisis isn't averted. Using energy for these during an emergency would be, as the saying goes, rearranging deck chairs on the Titanic.

You may be familiar with cortisol's pharmaceutical name: hydrocortisone, used in creams to reduce itchiness, swelling, and inflammation from rashes or insect bites though you may also know that overly-frequent use of hydrocortisone can cause skin damage. This is a good example for thinking about glucocorticoids; in small doses they can be beneficial but bring them out too often and they end up doing more harm than good.

Homeostasis (Greek homeo – “similar” and stasis – “stand”) is the idea that the body works to maintain an optimal state. But when it comes to stress, how can we think about using the same response for different scenarios? How can the stress response help if you're too cold and also help if you're too hot? How can you have an optimal point for something like blood pressure if it depends on the situation?

To help correct this, we can consider an adjusted theory of homeostasis known as allostasis. Allostasis (from the Greek allo - “variable”) recognizes that the optimal state is not a set point but a range. Your optimal blood pressure for sitting on the couch watching Netflix is quite different from your optimal blood pressure for running a marathon. In fact, your “optimal” blood pressure will be changing more often than you might think, even needing to adjust for behaviors like standing up from the couch. (People with Shy-Drager syndrome fail to produce an adequate stress response and can faint from an inability to cope with the drop in blood pressure created by standing up). Allostasis recognizes that “optimal” covers a wide range of possibilities depending on context. Essentially allostasis is the idea that our bodies are always adjusting to maintain a consistent level of function (sometimes expressed with the phrase “constancy through change”).

Hans Selye (sell-yay) was a Hungarian endocrinologist who was born in Vienna but spent most of his professional career in Canada. He's considered one of the pioneers of stress research but Selye didn't set out to study stress. He began his work by trying to understand the effects of an ovarian extract on rats. He found that rats repeatedly injected with the extract developed swollen adrenal glands, a smaller thymus, shrunken lymph glands, and peptic ulcers, which are holes in the lining of the stomach. These initially seemed to be effects of the extract but control rats given saline injections also developed these symptoms. Selye theorized that it was the chronic stress of painful injections that was causing these effects. He then subjected rats to many different stressors (cold exposure, heat exposure, trauma, infection) and found that chronic stress reliably enlarged adrenal glands, shrunk the thymus and lymph glands, and created peptic ulcers.

Based on this research, Selye proposed a general three-stage process of adaptation to any stressor, which he called General Adaptation SyndromeGeneral Adaptation SyndromeSelye's three-stage model of the body's response to chronic stress: alarm, resistance, and exhaustion. (GAS). The first stage of GAS is Alarm, in which the body mobilizes resources to confront the threat. If the stressor continues for an extended period of time, the body enters the second phase, known as Resistance. In this phase, the body adapts to the high level of arousal by drawing on muscle and fat to maintain energy while shutting down sex drive and processes for digestion and growth in order to conserve resources. If the stress continues, Selye believed the body enters the final phase of GAS, Exhaustion, during which the body's ability to resist collapses and the stressor causes organ damage, aging, or even death. You might create a mnenomic for General Adaptation Syndrome's 3 stages (Alarm, Resistance, Exhaustion) such as “People with GAS ARE stressed.”

While Selye was correct in identifying how various stressors could mobilize a similar response in the body, later research has shown that the stress response is not identical for all stressors. While there are many similarities, different stressors can have different physiological signatures. Selye's last stage (exhaustion) hasn't held up to scrutiny either. Stressors don't exhaust the body's resistance and then cause damage, it's actually the continued stress response itself that damages the body. Stressors like cold exposure weren't causing Selye's rats to develop ulcers, the rats' own stress responses were responsible. This is where that class of steroid hormones known as glucocorticoids come into play. These hormones mobilize energy but can cause damage and weaken the immune system if the body isn't given a chance to recover. In order to better understand this process, we'll need to take a closer look at the immune system and how it functions.

The immune system is the body's defense against intruders, pathogens, and injury, acting as a surveillance and protection system that is distributed throughout the entire body. A great deal of the work is done by white blood cells known as lymphocytes. Lymphocytes come in two main types: T-cells, which originate from the thymus (thus the T), and B-cells, which originate from the bone marrow. Lymphocytes identify invaders then produce antibodies to fight them off. Other cells in the immune system include macrophages (Greek for “big eaters”) which consume invaders and damaged cells, as well as natural killer cells which destroy other cells.

So how does the stress response disrupt immune function? Those glucocorticoids we mentioned earlier (released by the adrenal glands during the stress response) can interfere with the immune system by slowing white blood cell formation and altering the function of lymphocytes, which increases susceptibility to infection and weakens the body's ability to fight invaders and repair itself. Sheldon Cohen and colleagues (1998) had healthy volunteers complete a stress survey, then gave them nasal drops containing a cold virus. They found that those who had reported chronic stress were more likely to become sick from the virus. Excessive glucocorticoids can also cause degeneration of neurons in the hippocampus and increase fat storage (particularly in the abdomen) which raises the risk of obesity and associated illnesses (heart disease, metabolic syndrome, type-II diabetes, etc.)

In order to do their jobs properly, it's vital that lymphocytes, macrophages, and natural killer cells can tell the difference between the “good guys” (your own healthy cells) and the “bad guys” (invaders and damaged cells that need to be removed). This is no easy task, and it's possible for errors to occur. This happens in autoimmune disorders such as rheumatoid arthritis or psoriasis. In these disorders, the immune system incorrectly determines that healthy cells represent threats, and then tries to destroy them. How are these autoimmune disorders treated? Patients are given massive doses of glucocorticoids, suppressing the immune system and reducing symptoms (though potentially causing other problems in the process).

Chronic stress can also cause shortening of telomeres, segments of DNA on the ends of chromosomes which control cell division. As telomeres shorten, the process of cell division is inhibited or eventually blocked completely. Telomeres naturally shorten with aging, but chronic stress accelerates this process, explaining why stress can make people appear to age rapidly. Mothers caring for chronically ill children showed shorter telomere length (as well as lower white-blood cell count) the longer they had been caring for the child.

The stress response seems pretty well-designed for physical stressors, preparing our bodies to flee or fight threats. But we also face psychological stressors, and the stress response isn't particularly well-designed for these, as we usually can't run from them or physically fight them off.

Unlike other species, we're able to anticipate threats and experience a stress response from anticipation alone. Your average gazelle on the savannah would certainly be stressed by the presence of a lion, but you probably won't find a gazelle experiencing a major stress response from thinking that maybe one day next week it will need to sprint from a lion. Yet we can manage to mount a stress response just by thinking about stressful situations. Just imagining having to make a presentation in class might be enough to make your heart race and your palms feel sweaty.

Because we can think about them at any time, anticipated threats can easily become chronic stressors. Once a gazelle escapes the lion's clutches it can recover from the stress of the event, which probably won't happen every day. For us, however, anticipated stressors can be non-stop, from family pressures to recurrent concerns related to school, work, finances, or our societal standing. If these stressors are flooding our bodies with glucocorticoids day after day, we can end up with the same problems Selye's rats faced.

We'll begin with one problem Selye's rats had: peptic ulcers. In the middle of the twentieth century, doctors knew that gastritis (inflammation of the stomach lining) led to ulcers, but they couldn't figure out what was causing gastritis in the first place. People who were stressed had more ulcers, so the assumption was that stress caused gastritis, which then caused ulcers. The only way to treat gastritis was to tell patients to reduce their stress and give them antacids to reduce some symptoms. It wasn't until 1982 that Australian researchers Barry Marshall and Robin Warren identified a bacteria, Helicobacter pylori, which was implicated in the formation of peptic ulcers (work for which they received the Nobel Prize in 2005). To prove the point, Marshall himself drank a petri dish containing a pure H. pylori culture which caused nausea and (crucially) gastritis within a matter of days. Physicians no longer had to deal with vaguely telling patients to reduce stress and could instead place blame for gastritis (and later ulcers) squarely on a microbial cause.

While it's still possible to develop gastritis and ulcers without Helicobacter pylori being present, H. pylori is extremely common and it's estimated that about 50% of people worldwide play host to it, most without symptoms or ulcers. In fact, the presence of H. pylori may even reduce the risk of other illnesses for some people. So why doesn't half the world suffer from gastritis and ulcers? Now we're back to the role of stress. Chronic stress weakens the immune system and this influences the body's ability to control levels of H. pylori. Chronic stress distracts the guards, allowing the bacteria to proliferate, as well as reducing the body's ability to repair damage the bacteria causes.

The stress response reduces digestion and part of the way this works is by reducing blood flow to the stomach (in order to increase blood flow to skeletal muscles). This reduction in blood flow means that the stomach is temporarily less able to repair itself. Do this day after day, and you might just find yourself developing symptoms of gastritis. This same pattern is seen with other invaders which are always in the body but are more likely to cause symptoms during periods of stress. Herpes (including cold sores), shingles, and periodontal disease (such as gingivitis) are all more likely to flare up when stress is high and immune function is low.

Cardiologists Meyer Friedman and Ray Rosenman first proposed that there was a personality type associated with greater risk of heart disease. This Type-A behavior pattern refers to people who are competitive and ambitious, feel a constant sense of time urgency, and become easily angered and hostile. In contrast, those with a Type-B behavior pattern have a more laid-back approach to life and are more cooperative, easy-going, patient, and less prone to sudden hostility or aggression.

Type-A people feel that there's never enough time to do everything, so they quickly become frustrated or angry when confronted with a traffic jam, a line at the grocery store, or a long wait at the doctor's office. In fact, part of the inspiration for investigating the relationship between personality and heart disease resulted from Friedman and Rosenman having to replace the armrests on the chairs in their waiting room frequently, as apparently their cardiac patients had a tendency to fidget; impatiently rubbing, squeezing, and pulling at the fabric of the chairs. Initial research by Friedman and Rosenman found that people with a Type-A personality had 7x more heart disease than their relaxed and easy-going Type-B peers.

In order to understand exactly how stress increases the risk of heart disease, we need a brief primer on what cardiovascular disease is. Atherosclerosis (from the Greek athera “gruel” + scleros “hard”), also known as arteriosclerosis, refers to the buildup of plaque on the walls of arteries. The walls become thick and hardened by inflammation and the gradual accumulation of white-blood cells, foam cells (macrophages filled with lipids), and cholesterol. This buildup of plaque increases blood pressure, so blood whips through arteries faster, potentially furthering damage and inflammation.

If a section of plaque is unstable, it can break off and this clot then enters blood circulation where it can block a blood vessel or an artery (this possibility increases as arterial walls thicken). If the blockage occurs in a coronary artery, it is a myocardial infarction, or a heart attack. If it occurs in a blood vessel in the brain, it is a stroke. This means that atherosclerosis increases the risk of both of these potentially-fatal outcomes, and the frequent blood pressure spikes of Type-A personality further increase risk. Later research has suggested that it's not so much the time urgency or ambition of Type-A that increases risk, but the frequent anger. Impatience may wear down armrests, but hostility increases heart rate and blood pressure and causes greater wear-and-tear on one's arteries.

Understanding exactly how much additional risk Type-A personality carries is difficult, however, because the hostile actions of Type-A individuals may relate to other factors. Their negative affectivity (more anger, contempt, fear, disgust, and nervousness) not only activates their stress response more often, it also makes it more likely that others will be hostile to them (this can be referred to as transactional hostility). This means that others are less likely to provide social supportsocial supportThe emotional, informational, and practical assistance provided by others — a major stress buffer., and a lack of social support is another risk factor for cardiovascular disease.

If Type-A personality hit a little too close to home for you, the good news is that it's possible to change by adopting stress management strategies. If you're not particularly Type-A yourself, you may still have to resist responding in kind when others initiate hostility. But when people are leaning on their car horns or berating others for trivial errors and minor delays, you might just find yourself feeling bad for them (and their poor arteries) and hoping they learn better ways to cope with stress.

Determining whether something is stressful has two main parts. The first, or primary appraisal, involves asking the question “is this a threat or not?”. If not, there's no need to activate the stress response.

If something has been determined to be a threat, the next step in the appraisal process is secondary appraisal, which refers to figuring out how to respond to the threat by asking the question, “can I do anything about it?”. Stressors which can't be managed or controlled create a greater stress response.

The answer to whether or not we can control a stressor might not always be straightforward. In fact, two people may answer this question differently for the same stressor. So the level of perceived controlperceived controlThe belief that one has the ability to influence outcomes — a key buffer against stress. varies. This is the difference between the student who experiences stress over an impending exam and studies more (exerting control over the outcome) versus the student who feels powerless, experiencing stress but feeling that nothing can be done about it.

David Glass and Jerome Singer (1972) conducted a series of studies which exposed participants to predictable or unpredictable noises, then had the participants work at tasks requiring concentration, such as proofreading or solving puzzles. In some variations, after initial noise exposure participants were told there was a switch they could use to turn off the noise, while other participants did not have this control. The participants with access to the switch showed better performance on the tasks, even though they never actually used the switch (there weren't any noises after the switch was shown to them), supporting the idea that perceived control can reduce the effects of some stressors. It seems that participants with access to the switch felt they were prepared for the potential stressor, and this allowed them to focus on the tasks more fully. Other research has linked greater perceived control in the workplace to higher work satisfaction, improved well-being and work performance, and greater immune function.

In a series of well-known studies, Martin Seligman and Steven Maier placed dogs in a box that gave them electric shocks. Some dogs were able to turn the shocks off, while other dogs had no control. When later placed in a box in which all dogs could escape the shocks (by jumping over a divider) those who had previously been unable to avoid shocks did not attempt to escape. They seemed to have given up hope and sat there accepting the new shocks. These dogs perceived that they had no control over this stressor and this was named learned helplessnesslearned helplessnessThe passive resignation that develops after repeated experiences with uncontrollable events..

Learned helplessness has been replicated in rats, fish, insects, primates, and humans. In one study, Donald Hiroto and Martin Seligman found that human participants initially presented with an inescapable noise later showed slower learning for a task that could turn the noise off. Rats taught to be helpless seem to be depressed; they spend less time grooming, have disturbed sleep patterns, show less interest in sex and food, engage in self-mutilation (by biting themselves), and, to bring us back to the stress response, they have elevated levels of glucocorticoids in their bloodstreams.

Seligman and Maier also found that laboratory-raised dogs learned to be helpless more easily than dogs who had been caught by the pound (and had presumably been roaming free). This suggests that learning a sense of control in other areas can build resistance to helplessness, perhaps because one realizes that while the shocks are bad, they are just one situation in which control has been lost. Laboratory animals may have reduced control over many other aspects of their lives, increasing their risk of developing helplessness.

How much control we have over our environment may depend on our position in the social hierarchy. Those who are high status may feel (or actually have) a greater sense of control over many aspects of their lives, reducing their stress response to some stressors. This isn't the case in all species, however, and sometimes it's not so good to be the king, particularly if the hierarchy is unstable. Holding the highest rank may mean that one is constantly challenged. In these cases, having to fend off rivals day after day takes its toll, and higher status is associated with higher levels of glucocorticoids.

So where do humans fit in? Drawing conclusions about the role of rank for humans can be difficult for a number of reasons. In many human hierarchies, we aren't competing for vital resources like food, but for luxury products, prestige, and perceived importance. We may confuse rank with personality traits associated with dominance, such as those traits we saw in Type-A personality, which contribute to stress. It can also be difficult to assess control in human hierarchies, such as for middle-managers who feel they have increased responsibilities but reduced control.

Despite these difficulties, it does seem that for humans being on top can provide a sense of control that mitigates stress. This may explain why high-ranking British civil servants get sick less often than their subordinates and show reduced risk of several illnesses (see Marmot et al, 1978 and Rossum et al, 2000). It may also explain why Oscar-winners tend to live an average of 4 years longer than their nominated-but-non-winning peers.

In contrast, low SES (socioeconomic status - a combination of education, income, and occupation) is associated with poorer health. Poverty represents the greatest risk factor in all of behavioral medicine and the stressors of poverty include physical stressors (hunger, manual labor, increased work-related accidents and injuries, chronic sleep deprivation from working multiple jobs), psychological stressors (lack of control, financial worries, fewer resources to deal with problems that arise), and environmental stressors (noise, pollution, poor housing conditions, crowding, high-crime neighborhoods).

Once basic needs are met, however, understanding how status influences us is complicated by the fact that humans don't have one single hierarchy that influences all aspects of life. Our lives are varied and we are all members of multiple hierarchies, from family and friend groups, to school and the workplace, to hobbies and leisure activities. We may be high-ranking in some of these hierarchies and near the bottom of others. Just knowing someone's station at work doesn't tell us much if that person is more concerned with status in a different social hierarchy. The guy who just barely managed to finish a community 5K run after recovering from a long illness may feel he's on top of the world, while the competitive runner who thought he'd get first but came in second may feel utterly defeated.

A stronger sense of control isn't always better and there are situations in which perceived control increases stress. Sherman James identified one damaging relationship with perceived control which he labeled John Henryism; the belief that one can overcome any challenge with enough effort. James coined the term after interviewing a patient of his with hypertension (high blood pressure) named John Henry Martin. Like the legendary African-American railroad worker whose efforts to outwork a steam-powered spike driver ended in his victory and his death, John Henry Martin cared about success and believed he could control all outcomes if he just worked hard enough. While this might sound like an empowering example of an internal locus of control, the truth is that not everything can be controlled by one's work ethic, no matter how strong it may be.

Individuals with John Henryism (frequently working-class African-Americans) believe they just need to push themselves harder, and tend to blame themselves for failures or shortcomings. When it comes to overcoming societal prejudice, discrimination, and injustice, however, it's not always the case that one can simply work harder. The message that managing these issues is a matter of individual effort is not only unfair, it's dangerous. There's a price to be paid for the continuous copingcopingThe cognitive and behavioral strategies used to manage the demands of stressful situations. involved in confronting a stressor like prejudice day in and day out. Trying one's best to monitor social interactions for prejudice, avoid confirming negative stereotypes, and work to make up for discrimination takes its toll. James found that ratings on traits of John Henryism (agreeing with statements such as “When things don’t go the way I want them to, that just makes me work even harder”) were associated with greater cardiovascular reactivity to stress, and increased risk of hypertension. More recent research has also suggested that disadvantaged children with a high sense of self-control show more rapid immune cell aging (see Miller et al, 2015).

We might also wonder how choice influences our perception of control. As Barry Schwartz notes in his book “The Paradox of Choice”, sometimes having more options makes choosing all the more difficult. We seem to have more autonomy and control over our lives than ever before, but this greater perceived control introduces greater responsibility. We may feel that we are to blame when things go wrong, perhaps we could have avoided this if we had just made better choices. If you're unhappy in a world where you seem to have unlimited choice, the implication is that you've chosen poorly and your unhappiness is your own fault.

Sometimes it's better to have greater cognitive flexibility; the ability to switch locus of control from internal to external, depending on circumstances. In other words, if you've accomplished something, it's probably good to feel that you had a sense of control so you can take credit for it, but when something terrible happens to you for no good reason, blaming yourself isn't going to help and will worsen stress. In these cases we need to switch to an external locus of control, accepting our lack of control and placing blame outside ourselves (fortunately most of us tend to show this self-serving bias; taking credit for our successes and blaming failures on others).

While it's true we have control over some factors related to our health (exercise, diet, etc.) that control is limited. When bad things happen, sometimes it's best to realize you had no way of preventing them. The same can be true when bad things happen to others. We should avoid the just-world bias that causes us to blame victims of disease as if they somehow deserve their suffering. Sure, treat people well and they're likely to treat you well, but the rest of the universe is indifferent. Microbial invaders don't care how kind you are, cancer doesn't believe in karma, and life-altering injuries can happen to anyone in an instant. These are facts we must learn to live with, and more importantly, facts we must remember when we see others fall ill.

One more thing about blame. Later in this chapter we'll see strategies for coping with stress, but before we do, I'd like to note that those recommendations are mostly for minor-to-moderate stressors. They are not cure-all approaches and they don't address social and economic origins of stress. Thinking of stress as a cause of illness (rather than a risk factor) can unintentionally place blame on people for being sick. Suggesting that people struggling with the overwhelming stress of poverty just need to relax, go for a jog (through crime-ridden neighborhoods), or eat healthier (when neighborhood stores only stock processed foods) implies that if they don't, their stress is their own fault. While we might not like to admit it, the impact of poverty on health can't easily be smiled or meditated away and expecting that it can places an additional burden on those who most need help.

PTSD (Post-Traumatic Stress DisorderPost-Traumatic Stress DisorderA disorder that develops in some people after exposure to traumatic events — involves flashbacks, avoidance, and hyperarousal.) is a psychological disorder in which patients show 4 main types of symptoms. These symptoms include intrusive thoughts, memories, nightmares, and “flashbacks” of traumatic events, heightened physiological arousal (such as hypervigilance, sleep disturbance, and increased startle response), avoidance of memories, thoughts, feelings, or situations related to the trauma, and negative mood and cognition, which may include emotional numbing, guilt, memory and concentration problems, or suicidal thoughts. Symptoms must persist for at least one month in order to warrant diagnosis. While it was previously classified as an anxiety disorder, the DSM-5 now classifies PTSD within trauma and stress-related disorders.

This disorder has historically been associated with military combat, described as “shell shock” during WWI, and “combat fatigue” during WWII, and has frequently been diagnosed in the victims, witnesses, and perpetrators of war. PTSD is associated with other traumatic events such as assault, domestic abuse, rape, hostage situations, natural disasters, and terrorist attacks, which can result in diagnoses for victims or for others who must face these scenarios (police officers, firefighters, emergency response teams, and other health workers).

Not everyone who confronts these extreme stressors develops PTSD, so what other risk factors are relevant? It shouldn't be surprising that other risk factors relate to stress, such as low socioeconomic status, other preexisting mental disorders, prior childhood abuse and trauma, and low social support.

Another possible risk factor relates to physiology and the nervous system, as greater sensitivity to glucocorticoids and smaller hippocampal volume have been indicated in predicting the likelihood of developing PTSD in response to extreme stress. To examine whether hippocampal volume was a consequence of PTSD or an existing risk factor, Mark Gilbertson and colleagues looked at pairs of identical twins in which one twin saw active combat and the other did not, finding that twins with smaller hippocampal volume were more likely to develop PTSD if exposed to combat situations. Research by Douglas Bremner has found that PTSD seems to cause permanent shrinking of the hippocampus. So it may be the case that smaller hippocampal volume is a risk factor, but also a consequence of PTSD. Surprisingly, people with PTSD tend to show lower levels of glucocorticoids, but this may be because they are more sensitive to glucocorticoids. PTSD also increases one's risk of heart disease and asthma (not surprising given their relationship with stress).

As with Type-A or Type-B behavior patterns, we might think about responsiveness to stress as a personality trait. Susanne Kobasa first referred to the ability to withstand stress as hardinesshardinessA stress-buffering personality trait combining commitment, control, and challenge. in her initial studies of business executives who seemed to thrive in stressful circumstances, and this trait has since been studied in a number of other high-stress jobs, including military special forces, police officers, firefighters, and even students facing academic stress.

Kobasa identified three main traits of people who were hardy (or stress-resistant), which can be remembered as the 3 Cs of coping:

Commitment – Stress-resistant people show an active involvement with life, believing that their pursuits are important and meaningful.

Challenge – Rather than seeing change (and the stress the comes with it) as a threat, these individuals view change as an opportunity for continuous growth and improvement.

Control – Hardy people believe that they have causal influence over their life and that their behaviors make a difference.

You might recall some other ideas from personality that seem relevant here such as Julian Rotter's locus of control or Albert Bandura's self-efficacy. Hardiness can also been seen as a factor in understanding resilience and those who are hardy are more likely to survive or even thrive in the face of adversity. Life-changing accidents and injuries, loss of loved ones, and episodes of severe trauma represent extreme circumstances of stress and hardiness may play a role in how individuals respond and recover. There's also evidence that resilient people not only recover from traumatic events but experience post-traumatic growth, finding a greater sense of purpose and meaning for their lives and feeling stronger as a result of the challenges they have overcome.

Is hardiness a fixed personality trait, or are there ways to develop it? The research is encouraging and hardiness training may help people learn how to respond to stress in more positive ways. Training to improve hardiness tends to focus on three main techniques.

Reappraisal of the stressful stimulus or situation to consider how it could be better or worse, followed by consideration of what could be done to ensure that the better version happens. This helps the person to create a plan and increases perceived control.

Focusing helps a person get unstuck from the belief that they have no control by focusing on how stress feels in the body, which emotions are involved, and how these can be compensated for. When things are out of our hands, we can still exert control over our response to uncontrollable events and circumstances.

Compensatory self-improvement emphasizes how a person could improve from a stressful experience, either by learning how to overcome the stressor, or by using the experience to learn more about the self.

Salvatore Maddi has studied the effectiveness of hardiness training and one study found that students taught these approaches showed GPA improvements which continued for 2 years after the training, suggesting a long-term benefit.

No matter how much we know about stress, we can't evade it. But stress isn't something we need to hide from, it's something we need to learn to live with. This means we need effective strategies for managing stress and coping with the inevitable stressors we will face.

There are three main ways of managing stress: appraisal-focused coping refers to reconsidering one's appraisal of a stressor (maybe this isn't a stressor), problem-focused copingproblem-focused copingStress management by directly addressing the source of the stressor. refers to confronting a stressor head on and finding strategies to eliminate or reduce it (it is a stressor but I can overcome it), and emotion-focused copingemotion-focused copingStress management by regulating one's emotional response to a stressor. refers to managing stress by focusing on one's emotional response to it, rather than on the stressor itself (it is a stressor, I can't overcome it, but I can deal with the emotions it causes).

If John is stressed by his Spanish class, one way he might deal with this is to reappraise the situation and decide not to care about his grades for this class and then he won't be stressed. This would be appraisal-focused coping. If Susan is stressed by Spanish class and she responds to this stress by creating flashcards, rereading assignments, and organizing review sessions with classmates, this would be an example of problem-focused coping. If Bill is regularly stressed by unavoidable traffic in his morning commute, he may confront this problem by using this time in the car to listen to his favorite podcasts. The stressor (traffic) is still there, but Joe has changed his emotional response to it (perhaps even enjoying this time spent in the car).

Another way of approaching emotion-focused coping is to calm physiological reactivity to stressors. This might be done in the form of medications (such as anti-anxiety drugs which reduce activation of the stress response) or through relaxation techniques and physical exercise, both of which can reduce reactivity.

Gary Schwartz pioneered the use of biofeedback, a technique that involves monitoring heart rate or muscle tension in order to learn greater control over these processes which are normally unconscious. By using a device to monitor heart rate or muscle tension, a person can learn how to consciously reduce the stress response. It seems that fancy biofeedback equipment isn't necessary for these benefits, and Herbert Benson has shown that simply sitting quietly and focusing on relaxation can evoke a relaxation response, in which heart rate, breathing, and muscle tension are reduced and immune function is boosted.

If we think about how stress prepares our body for movement and action, there's an intuitive logic to moving and using the energy that has been mobilized as a way of calming the stress response. This turns out to be true, and physical exercise is an excellent method for managing stress.

People who exercise regularly show greater feelings of self-efficacy, more energy, and they tend to be more extraverted and sociable. These types of correlations could work in the other direction (self-efficacy and energy cause you to exercise) but we can experimentally have people exercise and then see these effects occur. Physical exercise seems to improve psychological well-being, and just 10 minutes of aerobic exercise has been demonstrated to improve mood. Regular exercise reduces the risk of many chronic illnesses and has been used as an effective intervention for a number of mental illnesses including depression and anxiety disorders. Exercise has been shown to increase neurogenesis, the creation of new neurons, in the hippocampus. You may be familiar with “runner's high”, which refers to the release of endorphins, the body's natural painkillers, following a bout of exercise. These endorphins (as well as enkephalins) boost mood, relieve pain, and improve quality of sleep.

Ironically, while exercise is an effective strategy for relieving stress, stress can become a barrier which prevents people from exercising. Feeling that they have too much work and too little time, people may fail to get adequate exercise, even though it would help to reduce their overall stress level (and improve their health). Exercise can be a way of exerting control and feeling a greater sense of self-efficacy, though it's important to note that this only refers to voluntary exercise. Rats given the opportunity to engage in exercise by running on a wheel show reductions in glucocorticoid levels, but those forced to exercise (for the same amount of time) show increases in their glucocorticoid levels.

As with perceived control, it might be possible to have too much of a good thing. While moderate exercise is associated with increased testosterone in males, those who run more than 40 miles per week actually show higher glucocorticoid levels and lower reproductive function (decreased testosterone production and smaller testes). Females who engage in excessive exercise also show reductions in reproductive function, including delayed onset of puberty and amenorrhea (cessation of menstruation). Overexercise can also lead to decreased bone density in both males and females (probably caused by the elevated glucocorticoid levels).

Moderate exercise may engage multiple aspects of stress management, providing people with a sense of control over their lives and their health. Exercise can also provide a source of social engagement and group cohesion, whether in the form of an organized team or just a jogging partner. Social support is another component of stress management, and this means that exercising with a friend may allow you to fight stress on two fronts.

Social support, which refers to feeling loved, valued, and connected with others, is an important factor for coping with stress. Social support can come in a variety of forms. It may be in the form of tangible support, such as cooking a meal for someone, it might be informational support, such as providing advice or suggestions to a friend, or it could simply be emotional support, helping to comfort someone who is struggling. There's a balance between support and control, however and in some cases, it may be better for social support to be invisible support, particularly when assistance could be seen as a threat to self-esteem or perceived control.

Sometimes being there “just in case” might be all that is needed. As with perceived control, sometimes there's a benefit from perceived support, even if that support is not actually used. In other words, knowing there's a friend you could call might help, even if you never actually pick up the phone.

When it comes to identifying the benefits of social support we need to remember that those who enjoy the greatest social support may have other traits related to their ability to manage stress, such as greater social skills and social competence, which may help reduce their anxiety. We should also consider that not all social support is positive and others may encourage negative thinking patterns or harmful behaviors like smoking, alcohol consumption, or drug use. It's also possible for support to be intrusive, violating our privacy and increasing, rather than reducing, stress levels. We can probably all imagine at least one person we'd rather not be around while dealing with stress.

The benefits of social support in the face of acute stress can be demonstrated in the lab. In one study, women were exposed to the threat of electric shocks to the ankle while in an fMRI scanner which monitored their brain activity. Women who were alone showed the highest threat response activation, those who held a stranger's hand showed a slight reduction in activation, and those who held their husband's hand showed the greatest reduction of the threat response. In fact, this reduction was greatest in those couples who had reported a high quality of marriage (see Coan, Schaefer, & Davidson, 2006).

Being a member of a group can provide “social capital”, which refers to a sense of community, trust, and reciprocity among members. When members of a community see each other as equals, there's less hierarchy, reductions in exerting dominance over others, and a greater sense of looking out for one another. This all sounds great, but we have to remember that groups can provide social capital to members in a way that is harmful to others. There's a risk that what's great for members can still be destructive to society as a whole, if tight-knit groups become intolerant, prejudiced, or actively discriminatory against outsiders.

Religious communities and spirituality can provide a form of social support and those who express greater religiosity or spirituality tend to have better health outcomes, recover faster from illnesses and live longer. This may be in part because religion provides a way of thinking about the world and reappraising the meaning of stressful events. It may help increase perceived control over the otherwise uncontrollable. Devotion, piety, and the practice of rituals can provide ways of exerting control over the vicissitudes of life. Even when control seems impossible, one might trust that there's a deity keeping watch. When bad things do happen, faith may be of benefit, provided that one sees the misfortune as a challenge (my devotion is being tested) or part of an overall plan (there's a reason for my suffering).

Like many topics in this chapter, religiosity can be a double-edged sword. Those who struggle with their faith in hard times, or who see their misfortunes as punishments from an angry god show higher levels of stress. Believing that illnesses represent karmic comeuppance or that strength of faith can overcome cancer can cause people to blame victims and make them feel they deserve their illnesses. As with other sources of social support, religious groups may become insulated, shun outsiders, or engage in discrimination, inflicting more stress and hardship on the rest of the world.

Positive psychologyPositive psychologyThe scientific study of strengths, virtues, and factors that allow individuals and communities to thrive. is seen as a counterpoint to the study of illness and mental disorder. By considering the traits, behaviors, and cognitions of those who thrive, we may uncover the sources of health and well-being. Recognizing that happiness can mean many things to many people, researchers in positive psychology prefer to use the term subjective well-beingsubjective well-beingA person's overall evaluation of their life — includes life satisfaction and the balance of positive to negative emotions. rather than “happiness” (though the latter still seems superior for best-selling book titles). We've already seen a few cognitive and behavioral strategies for improving health and well-being, now we'll take a look at some of the other areas of research in positive psychology.

In addition to hardiness, there are other personality traits associated with well-being. One of these is optimismoptimismA general expectation that good things will happen — associated with better health, resilience, and well-being., which refers to a tendency to “expect the best”, even in negative circumstances. In contrast, pessimism refers to the expectation that things will continue to be bad, or get worse. Optimism appears to be slightly heritable, though this doesn't necessarily mean that one's level of optimism can't be changed. Martin Seligman has proposed “learned optimism” as an opposing strategy to his “learned helplessness” discussed earlier.

Optimism is associated with a number of positive health outcomes and patients with higher levels of optimism prior to surgery have been shown to have better post-operative health and faster recovery (see Scheier et al, 1999). As for whether optimism can be learned, Seligman and Gregory Buchanan found that college students who attended 16 hours of learned optimism training reported fewer health problems and had lower incidence of depression than a control group over the following 18 months.

How much does our external environment influence our well-being? Would you be happier if you were living in a palace rather than an apartment, or driving a luxury coupe instead of a clunker? Environmental changes can make us happier, but this may not last as long as we expect.

Even extreme changes in environment don't seem to cause long-term changes in happiness, perhaps best demonstrated by Brickman, Coates, and Janoff-Bulman's study of lottery winners and paraplegics. While these major life events did cause short-term changes in happiness, people tended to revert back to their previous levels of happiness. This suggests that despite some peaks and valleys, we have a “happiness set point” which isn't strongly influenced by our environment.

Daniel Gilbert has suggested that we have a kind of “psychological immune system” that we aren't usually aware of. We think we know what will make our future selves happy but our ability to predict our future emotional states (known as affective forecasting) is actually quite poor. As a result we end up chasing the things we think will make us happy rather than focusing on those things that can actually raise our well-being.

Perhaps the most obvious thing that people chase in search of happiness is money. Poverty is devastating and can decrease well-being in a number of ways, so being able to meet basic needs and have some financial security can indeed boost happiness. But more and more wealth does not mean more and more happiness. And of course, we all already know this, as the struggles of celebrities and the super-rich are popular tabloid fodder, and remind us that money doesn't solve all problems.

Research by Daniel Kahneman has suggested that after about $70,000 per year, increased wealth shows diminishing returns (or diminishing marginal utility for the economists reading this) meaning that as you earn more, each dollar contributes less to improving well-being.

It seems that as we move up, we adjust to our new surroundings and they no longer boost our well-being. This idea that we continually adjust to our new positive experiences is referred to as the adaptation level phenomenon or, more memorably, the hedonic treadmill. Making more money doesn't necessarily make you happier because as you move up, you start comparing yourself to those who make even more than you do. Essentially you move up to the next level of comparison. When you make $25,000/year then earning $75,000 seems like just what you need, but once you're making $75,000 you start comparing yourself to people making more and wishing you could reach $100,000.

This kind of social comparison is key for understanding well-being. It's not just a matter of having “enough”, it's about defining what “enough” is based on the people around you. In this way, it's not so much actual deprivation that makes many Americans unhappy, it's their feeling of relative deprivation when they compare themselves to those who are doing better, known as upward comparison. A perfectly functional old Toyota that gets you everywhere you need to go doesn't feel like the luxury it is when you park it in a lot filled with Mercedes.

One way to reduce feelings of relative deprivation is to consider those people who are worse off than you are, known as downward comparison. That Toyota starts looking like a luxury again when you remember that some people can't afford a car at all. Or that the vast majority of human beings who have ever lived never had access to a car in their entire lives. It's tough to feel bad for yourself when you realize there are millions or even billions of people around the world who would gladly trade places with you right now, and that's not including all those who have previously lived and died before our modern times. The lifestyles of kings and emperors would happily be traded for air-conditioning, antibiotics, and whatever this Internet thing is.

So what can we do to boost our well-being in a lasting way? Are there interventions which can raise our happiness set-points and then keep them there? Indeed there are, and some will come as no surprise. Physical exercise, performing acts of kindness, and regularly experiencing and expressing gratitude have all been shown to raise people's overall level of well-being in the long-term.

Perhaps the key to understanding this chapter is to recall the concept of allostasis: finding balance in a world that never stops shifting, finding stability by always moving. Stress is inevitable, so we can only hope to find balance among tides which constantly turn.

Feel a sense of control over life, but recognize when control is out of your hands. Allow ambition to drive achievement without fueling hostility. Manage stress through exercise, but don't overdo it. Encourage strength, support, and social capital within your communities, but avoid the temptation to disparage outsiders. Balance optimism with acceptance, strive to improve while savoring what you have, and use downward comparison to feel grateful without developing a sense of superiority.