Health Psychology PDF

write me 40 bullet point notes of this: People generally think about health and well-being in biological and medical terms. The traditional Western medical model defines health simply as the lack of disease. This approach focuses on disease states and the treatments to cure them. It views people...

write me 40 bullet point notes of this: People generally think about health and well-being in biological and medical terms. The traditional Western medical model defines health simply as the lack of disease. This approach focuses on disease states and the treatments to cure them. It views people as passive recipients of disease and of the medical treatments designed to return them to health after illness. The underlying assumption is that people's mental states have little effect on their physical states, in either health or disease. Nearly four decades ago, psychologists, physicians, and other health professionals came to appreciate the importance of lifestyle factors to physical health. They launched the interdisciplinary field of health psychology, which integrates research on health and on psychology. Health psychologists rely on the research methods of psychology to understand the interrelationship between thoughts (health-related cognitions), actions, and physical and mental health. These researchers address issues such as ways to help people lead healthier lives. They study how behavior and social systems affect health and how ethnic and sex differences influence health outcomes. Health psychologists also study the inverse of these relationships: how health-related behaviors and health outcomes affect people's actions, thoughts, and emotions. I 11.1 Social Context, Biology, and Behavior Combine to Affect Health A central lesson in this chapter is that both mental states, such as outlook on life, and behaviors are critical in preventing illness, helping people regain health following illness, and helping achieve well-being. Well-being is a positive state that is sought by striving for optimal health and life satisfaction. To achieve optimal health, people need to actively participate in health-enhancing behaviors. How do people's personalities, thoughts, or behaviors affect their health? To answer this question, you need to understand the biopsychosocial model. According to this model, health and illness result from a combiPsychological factors thoughts/actions, lifestyles, stress, health beliefs nation of factors, such as biological characteristics (e.g., genetic predisposition), behavioral factors (e.g., lifestyle, stress, and beliefs about health), and social conditions (e.g., cultural influences, family relationships, and social support). Research that integrates these levels of analysis helps to identify strategies that may prevent disease and promote health. Biological characteristics genetic predispositions, exposure to microbes, brain and other nervous system development FIGURE 11.1 Social conditions environments, cultural influences, family relationships, social support The Biopsychosocial Model This model illustrates how health and illness result from a combination of factors. CHAPTER 11 HEALTH AND WELL-BEING As shown in FIGURE 11.1, thoughts and actions affect people's choices of the environments they interact with. Those environments, in turn, affect the biological underpinnings of thoughts and actions. To understand how this continuous loop operates in real life, suppose a person is genetically predisposed to be anxious. He learns that one way to reduce his anxiety is to eat comfort foods such as potato chips, cookies, and ice cream. If he consumes these foods in excess, he may gain weight and eventually become overweight. Some people have genes that make becoming overweight more likely. Overweight people often find that exercise is not very pleasant. If their extra weight makes even moderate exercise difficult, they may decrease their physical activity. That decrease might slow down their metabolism. The slower metabolism and decreased activity would likely cause them to gain weight. The circle would repeat. Additional examples of the interplay between biological, social, and psychological factors are presented throughout this chapter. CAUSES OF MORTALITY Before the twentieth century, most people died from infections and from diseases transmitted person to person. Infections and communicable diseases remain the leading causes of mortality in some developing nations, but in most countries the causes have shifted dramatically. For example, in the United States people are now more likely to die from heart disease, cancer, strokes, lung disease, and accidents than from infectious diseases (Heron, 2016). All of these causes of death are at least partially outcomes of lifestyle. Daily habits such as poor nutrition, overeating, smoking, alcohol use, and lack of exercise contribute to nearly every major cause of death in developed nations (Smith, Orleans, & Jenkins, 2004). Ifbeing healthy means being physically active, not smoking, eating a healthy diet, and maintaining the recommended body fat level, then fewer than 3 percent of Americans meet all those criteria (Loprinzi, Branscum, Hanks, & Smit, 2016). Partially for this reason, life expectancy in the United States dropped in 2015, the first time this has happened in several decades (Xu, Murphy, Kochanek, & Arias, 2016). A dramatic rise in unintentional poisonings, mainly opioid overdoses, was the leading cause of higher death rates (the opioid epidemic is discussed in Chapter 4). life expectancy than white Americans (Kochanek, Murphy, Xu, & Tejada-Vera, 2016). For children born in the United States in 2014, life expectancy varies as follows: 81.4 years for white females, 76.7 years for white males, 78.4 years for African American females, and 72.5 years for African American males ( Centers for Disease Control and Prevention, 2016a). The reasons that racial and ethnic groups experience differences in their health include genetic variation in susceptibility to some diseases, access (or lack of access) to affordable health care, and cultural factors such as dietary and exercise habits (Cockerham, Bauldry, Hamby, Shikany, & Bae, 2017). African Americans are less likely to have cancer screenings. Moreover, they are less likely to receive recommended treatments, and perhaps as a result they have lower survival rates (DeSantis, Naishadham, & Jemal, 2013). Racial biases inherent in the U.S. medical system contribute to health disparities (Klonoff, 2014). The gap between black and white Americans has been closing over the past few years, but mainly because white Americans aged 25- 54 are dying at higher rates (Kochanek, Arias, & Bastian, 2016). Lifestyle factors, such as alcohol and opioid abuse, have lowered life expectancy more for white, rural Americans than for other racial or ethnic groups (Case & Deaton, 2015; Keyes et al., 2014). In impoverished countries, the resources may be lacking to provide adequate treatments for many health conditions, such as HIV, malaria, and rotavirus, an intestinal virus that kills over a half million children each year. The Bill and Melinda Gates Foundation has provided billions in grant funding to reduce infectious diseases in poor countries. Efforts such as these have lowered deaths from malaria by 42 percent globally and nearly 50 percent in Africa, where, on average, hundreds of children die each day from malaria (World Health Organization, 2014). Vaccines for rotavirus have led to dramatic reductions in childhood hospitalization and death around the globe, including in North America (Parashar et al., 2013). Different lifestyles also contribute to health differences. Consider that in some countries, people most often walk or ride bicycles for transportation. In the United States and Canada, people often drive or use public transportation, so their physical activity comes not from daily activity but from purposeful exercise. These differences in health behaviors have long-term consequences for people's health and expected life spans (FIGURE 11.3). For example, the adoption of more Westernized lifestyles in countries like India and China, such as eating junk food and engaging in less physical activity, has led to dramatic increases in diseases related to obesity, such as diabetes (Zabetian, Sanchez, Narayan, Hwang, & Ali, 2014). Thus, researchers seek to understand how culture influences behaviors and how behaviors alter underlying biology. Each level of analysis provides a piece of the intricate puzzle that determines health and well-being. over 25 are considered overweight, whereas those with BMis over 30 are considered obese. There are at least two issues with the use ofBMI to predict health. First, BMI does not take age, sex, bone structure, or body fat distribution into account. Athletes or those with significant amounts of muscle may have high BMis despite being in excellent physical condition (Rothman, 2008). Perhaps because of these limitations, a second issue is that a clear relationship between BMI and health outcomes does not exist exc;ept for the very obese. One recent approach has been to calculate body shape index, which considers the amount of abdominal fat relative to BMI (Krakauer & Krakauer, 2012). In two large studies in the United States and the United Kingdom, this method was found to predict health outcomes better than BMI alone did (Krakauer & Krakauer, 2014). BODY WEIGHT AND HEALTH OUTCOMES A meta-analysis (Flegal, Kit, Orpana, & Graubard, 2013) looked at 97 studies that included nearly 3 million individuals, of whom 270,000 had died during the various study periods. The researchers found that people who were slightly overweight (BMis 25-30) had a lower probability of dying from any cause during the study periods than people with recommended BMis of less than 25. Moreover, slightly obese individuals (BMis less than 35) did not have a greater risk of death than those with BMis under 25. Individuals with BMis over 35, however, were much more likely to die. These findings are controversial. Some researchers have suggested that these findings underestimate the risk of obesity because those with poor nutrition, with chronic illnesses, or who smoke tend to be thin, and therefore these groups might artificially inflate the health risks of having a low BMI (Veronese et al., 2016). Indeed, individuals with low BMis are also at increased risk for premature death (Aune et al., 2016), particularly if they are elderly (Hughes, 2013). A meta-analysis of32 studies of nearly 200,000 people over age 65-living and dead-found that those whose BMis were under 23 or over 34 were much more likely to have died (Winter, Macinnis, Wattanapenpaiboon, & Nowson, 2014). Whether being slightly overweight is unhealthy or not is under debate. Meanwhile, it is increasingly clear that maladaptive eating habits, such as eating junk food, are likely responsible for much of the poor health associated with obesity. People who eat food high in both fat and sugar tend to store more body fat in the abdomen. These individuals are at increased risk for developing metabolic syndrome, a constellation ofrisk factors that includes high blood sugars, insulin resistance (in which the body produces but does not use insulin efficiently; see the discussion of insulin in Chapter 10), high blood levels of unhealthy cholesterol, and cardiovascular disease (Ford, Giles, & Dietz, 2002). Metabolic syndrome is the result of poor nutrition rather than bodyweight per se (Unger & Scherer, 2010). The amount of body fat that people store might be more important for health outcomes than is bodyweight per se (Padwal, Leslie, Lix, & Majumdar, 2016). Storing fat in the abdomen may have more influence on health than the amount of fat that is stored in the body overall (Sahakyan et al., 2015). People with low BMis but large amounts of abdominal fat are at higher risk for poor health, whereas people with high BMis who have fat distributed throughout their bodies are at lower risk for health problems (Ahima & Lazar, 2013). The bottom line, however, is that many obese people store fat in the abdomen and therefore have symptoms of metabolic syndrome. GLOBAL RISE IN OBESITY According to the World Health Organization (2016), obesity has doubled around the globe since 1980. Although developing nations have lower overall rates of obesity, their populations are becoming obese at a greater rate than developed nations (Ng et al., 2014). In the United States, the rate has jumped from less than 15 percent of the population in 1980 to 38 percent in 2014 (Flegal et al., 2016). Indeed, the numbers are even higher for racial and ethnic minorities, with more than half of African American women (56.7 percent) and nearly half of Hispanic women ( 43.3 percent) classified as obese. Extreme obesity (a) (having a BMI over 40), which was almost unheard ofin 1960, now charact erizes nearly 1 in 12 Americans (Fryar, Carroll, & Ogden, 2016; FIGURE 11.5). Likewise, the percentage of obese children has quadrupled since the 1960s. About 1 in 6 children in the U.S. is obese, with African American and Hispanic children much more likely to be so (Ogden et al., 2016). Given the health consequences associated with obesity, researchers have sought to understand why people are gaining weight and what might be done to reverse this trend. Understanding obesity requires a multilevel approach that examines behavior, underlying biology, cognition (how people think about food and obesity), and the societal context that makes cheap and tasty food readily available. In fact, obesity is an ideal example of the biopsychosocial model ofhealth presented earlier in the chapter. A~ you read about obesity, keep in mind the linkages between genetic predispositions, thoughts, feelings, and behaviors as well as the continuous loop through (b) 400 which these variables cycle. I Rats presented with FOOD AVAILABILITY AND OVEREATING An increase in the variety of available food is another factor that contributes to maladaptive eating and therefore obesity. For instance, rats that normally maintain a steady bodyweight when eating one type of food eat huge amounts and become obese when presented with a variety of high-calorie foods, such as chocolate bars, crackers, and potato chips (Sclafani & Springer, 1976; FIGURE 11.6). Humans show the same effect, eating much more when various foods are available-as at a buffet-than when only one or two types of food are available (Epstein, Robinson, Roemmich, Marusewski, & Roba, 2010; Raynor & Epstein, 2001). I a variety of high-calorie.. foods gained much Variety diet 350 I more weight than rats ----- that were given only one type of food. Body weight 300 (grams) 250 People also eat more when portions are larger (Rolls, Roe, & Meengs, 2007), and portion sizes have increased considerably in many restaurants. In addition, overweight people show more activity in reward regions of the brain when they see tasty-looking foods than do individuals who are not overweight (Rapuano et al., 2017). Together, these findings suggest that in industrialized nations, the increase in obesity and metabolic syndrome over the past few decades is partly explained by over0 1 2 3 4 5 6 7 8 9 1011121314 Days FIGURE 11.6 The Impact of Variety on Eating Behavior (a) If you were presented with this table full of delicious foods, how many would you eat? Would you be tempted to try them all? (b) As shown in this graph, rats wi ll become obese if given ample variety. eating. The overeating stems from three factors: the sheer variety of high-calorie foods, the large portions now served in many restaurants, and individual responses to food cues. SOCIAL AND GENETIC INFLUENCES Body weight may be socially contagious. One study found that close friends of the same sex tend to be similar in body weight (Christakis & Fowler, 2007). This study also found that even when close friends live far apart from each other, if one friend is obese, the other one is likely to be ~se as well. Studies of the social transmission of obesity suggest that it is not eating ti e same meals or cooking together that is critical. Instead, it is the implicit agreement on what body weight is acceptable or normal (FIGURE 11.7). If many of your close friends are obese, implicitly you learn that obesity is normal. Thus, subtle communications can affect how we think and act when we eat. Obesity also tends to run in families. Family and adoption studies indicate that approximately half the variability in body weight is genetic (Klump & Culbert, 2007). The BMI of adopted children is more strongly related to the BMI of their biological parents than to the BMI of their adoptive parents (Sorensen, Holst, Stunkard, & Skovgaard, 1992). Studies of identical and fraternal twins provide even stronger evidence of the genetic control of body weight. As discussed in Chapter 3, heritability refers to the proportion of variability, in a population, that can be attributed to genetic transmission of a trait from parents to their offspring. Estimates of the heritability of body weight range from 60 percent to 80 percent. Moreover, the similarity between the body weights of identical twins does not differ for twins raised together versus twins raised apart (Bouchard & Perusse, 1993; Wardle, Carnell, Haworth, & Plomin, 2008). This finding suggests that genetics has far more effect on body weight than environment does. If genes primarily determine body weight, why has the percentage of Americans who are obese doubled over the past few decades? Albert Stunkard, a leading researcher on human obesity, points out that genetics determines whether a person can become obese, but environment determines whether that person will become obese (Stunkard, 1996). In an important study conducted by the geneticist Claude Bouchard, identical twins were overfed by approximately 1,000 calories a day for 100 days (Bouchard, Tremblay, et al., 1990). Most of the twins gained some weight, but there was great variability among pairs in how much they gained (ranging from 4.3 kilograms to 13.3 kilograms, or 9.5 pounds to 29.3 pounds). Further, within the twin pairs there was a striking degree of similarity in how much weight they gained and in which parts of the body they stored the fat. Some of the twin pairs were especially likely to put on weight. Thus, genetics determines sensitivity to environmental influences. Genes predispose some people to obesity in environments that promote overfeeding, such as contemporary industrialized societies. Many genes are involved in obesity, as might be expected for such a complex condition: More than 300 genetic markers or genes have been identified as playing some role (Snyder et al., 2004). THE STIGMA OF OBESITY In most Western cultures, obese individuals are viewed as less attractive, less socially adept, less intelligent, and less productive than their normal-weight peers (DeJong & Kleck, 1986). Moreover, perceiving oneself as overweight is linked to depression, anxiety, and low self-esteem (Stice, 2002). Bear in mind, however, that researchers cannot randomly assign people to conditions related to weight, depression, anxiety, qr self-esteem. Therefore, most of the obesity research with human participants is correlational. For example, we can note links between being overweight and having low self-esteem, but we cannot say that one factor causes the other. However, the unfortunate practice of fat shaming likely contributes to body dissatisfaction for those who perceive themselves to be overweight. Indeed, fat acceptance advocates argue that anti-fat stigma contributes to the health problems and emotional problems associated with obesity. Not all cultures stigmatize obesity (Hebl yeatherton, 1998). In some developing countries, such as many African nations, b4g obese is a sign of being upper class. Obesity may be desirable in developing countries because it helps prevent some infectious diseases and reduces the likelihood of starvation. It may also serve as a status symbol in developing countries. That is, obesity may indicate that one can afford to eat luxuriously. In Pacific Island countries such as Tonga and Fiji, being obese is a source of personal pride, and dieting is uncommon. In 2013, more than half of men and nearly two-thirds of women living in Tonga were obese (Ng et al., 2014; FIGURE 11.SA). In most industrialized cultures, food is generally abundant. Indeed, in the United States fresh and nutritious foods are often more expensive than high-calorie fast food. Therefore, in the industrialized world, being overweight is associated with lower socioeconomic status, especially for women. The relative affordability of fast food may contribute to overweight among those with limited finances. The upper classes in Western cultures have a clear preference for very thin body types, as exemplified in fashion magazines (FIGURE 11.8B). The typical woman depicted by the fashion industry is 5 feet 11 inches tall and weighs approximately 110 pounds. In other words, the standard represented by models is 7 inches taller and 55 pounds lighter than the average woman in the United States. Such extreme thinness represents a body weight that is difficult, if not impossible, for most people to achieve. In fact, women report holding body weight ideals that are not only lower than average weight but also lower than what men find attractive (Fallon & Rozin, 1985). Is being thin always more healthy than being overweight? I 11.3 Dieting Is Seldom Effective and May Contribute to Eating Disorders Obese people typically try multiple diets and other "cures" to lose weight, but dieting is a notoriously ineffective means of achieving permanent weight loss (Aronne, Wadden, Isoldi, & Woodworth, 2009). Most individuals who lose weight through dieting eventually regain the weight. Often, they gain back more than they lost. Most diets fail primarily because of the body's natural defense against weight loss (Kaplan, 2007). Body weight is regulated around a set-point determined primarily by genetic influence. Consider two examples. In 1966, several inmates at a Vermont prison were challenged to increase their body weight by 25 percent (Sims et al., 1968). For six months, these inmates consumed more than 7,000 calories a day, nearly double their usual intake. If each inmate was eating about 3,500 extra calories a day (the equivalent of seven large cheeseburgers), simple math suggests that each should have gained approximately 170 pounds over the six months. In reality, few inmates gained more than 40 pounds, and most lost the weight when they went back to normal eating. Those who did not lose the weight had family histories of orJt ity. At the other end of the spectrum, researchers have investigated the short-te~ and long-term effects of semi-starvation (Keys, Brozek, Henschel, Mickelsen, & Taylor, 1950). During World War II, more than 100 men volunteered to take part in this study as an alternative to military service. Over six months, the participants lost an average of25 percent of their bodyweight (FIGURE 11.9). Most found this weight reduction very hard to accomplish, and some had great difficulty losing more than 10 pounds. The men underwent dramatic changes in emotions, motivation, and attitudes toward food. They became anxious, depressed, and listless; they lost interest in sex and other activities; and they became obsessed with eating. Many of these outcomes are similar to those experienced by people with eating disorders. Although it is possible to alter body weight, the body responds to weight loss by slowing down metabolism and using less energy. Therefore, after the body has been deprived of food, it needs less food to maintain a given body weight. Likewise, weight gain occurs much faster in previously starved animals than would be expected by caloric intake alone. In addition, repeated alterations between caloric deprivation and overfeeding are maladaptive and have been shown to have cumulative metabolic effects. That is, each time an animal is placed on caloric deprivation, the animal's metabolic functioning and weight loss become slower than they were the previous time. When overfeeding resumes, the animal's weight gain occurs more rapidly (Brownell, Greenwood, Stellar, & Shrager, 1986). This pattern might explain why "yo-yo dieters" tend to become heavier over time. RESTRAINED EATING Janet Polivy and Peter Herman (1985) characterize some chronic dieters as restrained eaters. According to Polivy and Herman, restrained eaters are prone to excessive eating in certain situations. These bouts of overeating may be occasional or not so occasional. For instance, ifrestrained eaters believe they have eaten high-calorie foods, they abandon their diets. Their mindset becomes, "I've blown my diet, so I might as well just keep eating." Many restrained eaters diet through the workweek. On the weekend, when they are faced with increased food temptations and at the same time are in less structured environments, they lose control. In one study, restrained eaters and unrestrained eaters each consumed a large milkshake (Demos, Kelley, & Heatherton, 2011). When the restrained eaters then viewed pictures of appetizing food, activity increased in the brain regions connected with reward. By contrast, when the unrestrained eaters viewed the same pictures, the reward activity in their brains was reduced. Presumably, the milkshake had satisfied the unrestrained eaters. Thus, the reward systems in the brains of restrained eaters seem to encourage additional eating after the eaters break their diets. Being under stress also leads restrained eaters to break their diets (Heatherton, Herman, & Polivy, 1991). Binge eating by restrained eaters depends on their perceptions of whether they have broken their diets. Dieters can eat 1,000-calorie Caesar salads and believe their diets are fine. But if they eat 200-calorie chocolate bars, they feel their diets are ruined and they become disinhibited. Becoming disinhibited means that after first inhibiting their eating, they lose the inhibition. In short, the problem for restrained eaters is that they rely on cognitive control of food intake: Rather than eating according to internal states of hunger and satiety, restrained eaters eat according to rules, such as time of day, number of calories, and type of food. If they feel that food is healthy, whether it is or not, they eat more ofit (Provencher, Polivy, & Herman, 2009). Such patterns are maladaptive and are likely to break down when dieters eat high-calorie foods or feel distressed. Getting restrained eaters back in touch with internal motivational states is one goal of sensible approaches to dieting. DISORDERED EATING When dieters fail to lose weight, they often blame their lack of willpower. They may vow to redouble the,"f_orts on the next diet. Repeated dietary failures may have harmful and permanent physiological and psychological consequences. In physiological terms, weight-loss and weight-gain cycles alter the dieter's metabolism and may make future weight loss more difficult. Psychologically, repeated failures diminish satisfaction with body image and damage self-esteem. Over time, chronic dieters tend to feel helpless and depressed. Some eventually engage in more extreme maladaptive behaviors to lose weight, such as taking drugs, fasting, exercising excessively, or purging. For a vulnerable individual, chronic dieting may promote the development of a clinical eating disorder. Although eating disorders affect both sexes, they are more common for women. It is possible that eating disorders are underestimated among males (Raevuori, Keski-Rahkonen, & Hoek, 2014). According to some research, being gay may increase the likelihood of eating disorders for men (Russell & Keel, 2002). The three most common eating disorders are anorexia nervosa, bulimia nervosa, and binge-eating disorder. Individuals with anorexia nervosa have an excessive fear of becoming fat and severely restrict how much they eat (FIGURE 11.10). This reduction in energy intake leads to an unhealthy body weight. Anorexia most often begins in early adolescence. Although this disorder was once thought to mainly affect upper-middle-class and upper-class Caucasian girls, there is evidence that race and class are no longer defining characteristics of eating disorders (Polivy & Herman, 2002). This change might have come about because media images of a thin ideal have permeated all corners of contemporary society. anorexia nervosa An eating disorder characterized by excessive fear of becoming fat and therefore restricting energy intake to obtain a significantly low body weight. Although many adolescents strive to be thin, fewer than 1 in 100 meet the clinical criteria of anorexia nervosa as described by the most recent Diagnostic and Statistical Manual of Mental Disorders (DSM-5), which was released in 2013 is discussed further in Chapter 14). There is evidence that adolescent boys and girls are equally likely to develop anorexia (Swanson et al., 2011). These criteria include both objective measures of thinness and psychological characteristics that indicate an abnormal obsession with food and body weight. Those who have anorexia view themselves as fat even though they are at a significantly low weight, often with BMis under 17. Issues of food and weight pervade their lives, controlling how they view themselves and how they view the world. Initially, the results of self-imposed starvation may draw favorable comments from others, such as "You look so thin you could be a fashion model." These comments might come from friends who are also influenced by social messages that being thin is an important part of being attractive. But as the anorexic approaches her emaciated ideal, family and friends usually become concerned. In many cases, medical attention is required to prevent death from starvation. This dangerous disorder causes a number of serious health problems, in particular a loss of bone density, and about 15-20 percent of those with anorexia eventually die from the disorder-they literally starve themselves to death (American Psychiatric Association, 2000b). Individuals with bulimia nervosa alternate between dieting, binge eating, and purging (self-induced vomiting) or other inappropriate compensatory behaviors, such as abusing laxatives or excessive exercising. Bulimia often develops during late adolescence. Approximately 1-2 percent of women in high school and college meet the criteria for bulimia nervosa. These women tend to be of average weight or slightly overweight. Bulimia is much more common in females than in males (Klump, Culbert, & Sisk, 2017). Bulimics are caught in a vicious cycle: In an effort to quell negative emotions, they eat large quantities of food in a short amount of time. This eating leads them to feel guilty that they may gain weight. They will then engage in one or more compensatory behaviors, such as self-induced vomiting, excessive exercise, or the abuse oflaxatives. Whereas anorexics cannot easily hide their self-starvation, binge-eating behavior tends to occur secretly. Although bulimia is associated with serious health problems, such as dental and cardiac disorders, it is seldom fatal (Keel & Mitchell, 1997). A disorder similar to bulimia is binge-eating disorder. The American Psychiatric Association officially recognized this condition as a disorder in 2013. People with the disorder engage in binge eating at least once a week, but they do not purge. These individuals often eat very quickly, even when they are not hungry. Those with bingeeating disorder often experience feelings of guilt and embarrassment, and they may binge eat alone to hide the behavior. Many people with binge-eating disorder are overweight or obese. Compared to bulimia, binge-eating disorder is more common among males and ethnic minorities (Wilfley, Bishop, Wilson, & Agras, 2007). Although bulimia and binge-eating disorder share many common features-differing most notably in that only bulimics purge-many researchers believe the two are distinct disorders (Striegel-Moore & Franko, 2008). Eating disorders tend to run in families. Like obesity, these disorders are due partly to genetics. The incidence of eating disorders in trf'/!'n.ited States increased into the 1980s (Keel, Baxter, Heatherton, & Joiner, 2007). This increase suggests that when people have genetic predispositions for eating disorders, they will tend to develop the disorders if they live in societies with an abundance of food. Bulimia seems to be more culture bound, meaning that there are large cultural variations in its incidence. Anorexia is prevalent in all societies that have abundant food. There are many effective treatments for eating disorders. Indeed, the outlook for those with eating disorders indicates reasons to be optimistic about outcome, with the majority symptom-free five years after diagnosis (Keel & Brown, 2010). Effective treatments focus on disordered thoughts, interpersonal relationships, and family Despite overwhelming evidence that smoking cigarettes leads to premature death, millions around the globe continue to light up (Fiore, Schroeder, & Baker, 2014). According to the World Health Organization (2008), increasing numbers of people are smoking in low-income countries, and 5.4 million deaths are caused by tobacco every year. Thirty percent of all smokers worldwide are in China, 10 percent are in India, and an additional 25 percent come from Indonesia, Russia, the United States, Japan, Brazil, Bangladesh, Germany, and Turkey combined ( FIGURE 11.11). According to the 2014 U.S. Surgeon General's Report, just under 1 in 5 American adults are current smokers (U.S. Department of Health and Human Services [USDHHS], 2014). ·ssaUU!4l awaJJxa aAa!4Je 01 saA1aswa41 aAJeJs e,xaJoue 4l!M aso41 seaJa4M '(DUIJIWOA paJnPU!-JloS) DU!DJnd pue 'DU!Jea aou!q 'DU!Jo!P uaaMJaq a1euJaJ1e e,w11nq 4JIM aso41 !tf3MSNV Smoking is blamed for more than 480,000 deaths per year in the United States and (b) decreases the typical smoker's life by more than 12 years (Jha et al., 2013). Most smokers begin in childhood or early adolescence. This early start concerns health care providers because of how nicotine may affect the developing brain. Every day, approximately 3,200 Americans ages 11 to 17 smoke their first cigarette (USDHHS, 2014). About half of young smokers will likely continue smoking into adulthood, and if current smoking rates continue, 5.6 million American children alive today will die prematurely because of smoking (USDHHS, 2014). Fortunately, there has been a dramatic reduction in adolescent smoking over the last decade (Johnston, O'Malley, Bachman, & Schulenberg, 2011). Regular smoking dropped from approximately 13 percent to 6.6 percent, with a 33 percent drop in the number of adolescents who even try smoking (Centers for Disease Control and Prevention, 2010; USDHHS, 2014). Smoking causes numerous health problems, including heart disease, respiratory ailments, and various cancers. Cigarette smoke also causes _health problems fornonsmoking bystanders, a finding that has led to bans on smoking in many public and private places. Besides spending money on cigarettes, smokers pay significantly more for life insurance and health insurance. Why do they continue to smoke?Why does anyone start? STARTING SMOKING It is hard-to imagine any good reason to start smoking. First attempts at smoking often involve a great deal of coughing, watering eyes, a terrible taste in the mouth, and feelings of nausea. So why do kids persist? Most researchers point to powerful social influences as the leading cause of adolescent smoking ( Chassin, Presson, & Sherman, 1990; FIGURE 11.12). Research has demonstrated that adolescents are more likely to smoke if their parents or friends smoke (Hansen et al., 1987). They often smoke their first cigarettes in the company of other smokers, or at least with the encouragement of their peers. Moreover, many adolescent smokers appear to show a false consensus effect: They overestimate the number of adolescent and adult smoker, (Sherman, Presson, Chassin, Carty, & Olshavsky, 1983). Adolescents who incorrectly believe that smoking is common may take it up to fit in with the crowd. Other studies have pointed to the potential meaning of"being a smoker" as having a powerful influence. For instance, research has shown that smokers are viewed as having positive qualities such as being tough, sociable, and good with members of the opposite sex. Children take up smoking partially to look "tough, cool, and independent of authority" (Leventhal & Cleary, 1980, p. 384). Thus, smoking may be one way for adolescents to enhance their self-images as well as their public images ( Chassin et al., 1990). As discussed in Chapter 6, adolescents imitate models through observational learning. Smokers on television and in movies are often portrayed in glamorous ways that appeal to adolescents (FIGURE 11.13). Researchers in Germany found that the more German children ages 10 to 16 watched popular North American movies that depicted smoking, the more likely they were to try smoking (Hanewinkel & Sargent, 2008; compare with Figure 6.40, which illustrates how adolescent smoking rates decline when movie depictions of smoking decline). By the 12th grade, 50- 70 percent of adolescents in the United States have had some experience with tobacco products (Centers for Disease Control and Prevention, 2010; Mowery, Brick, & Farrelly, 2000). Of course, it is hard to look tough while gasping and retching; so while most adolescents try one or two cigarettes, most do not become regular smokers. Still, many young people who experiment go on to smoke on a regular basis (Baker, Brandon, & Chassin, 2004). Over time, casual smokers become addicted. It is now widely acknowledged that the drug nicotine is of primary importance in motivating and maintaining smoking behavior (Fagerstrom & Schneider, 1989; USDHHS, 2004). Once the smoker becomes "hooked" on nicotine, going without cigarettes will lead to unpleasant withdrawal symptoms, including distress and heightened anxiety (Russell, 1990). Some people appear especially susceptible to nicotine addiction, perhaps because of genetics (Sabol et al., 1999). Nicotine may lead to increased activation of dopamine neurons, which can have a reinforcing effect. (The functions of dopamine neurons are discussed further in Chapter 3.) ELECTRONIC CIGARETTES People continue to smoke in order to obtain nicotine. Within the past few years, a new way to get nicotine has become increasingly popular: e-cigarettes. According to the 2014 U.S. Surgeon General's report (USDHHS, 2014), approximately 6 percent of U.S. adults have at least tried e-cigarettes. A positive aspect of e-cigarettes is that they do not contain tobacco or the thousands of chemicals, many of them cancer causing, that are in regular cigarettes. E-cigarettes also do not produce secondhand smoke, which can be harmful to nonsmokers. However, health officials do not yet know whether e-cigarettes are better or worse for individuals and society than traditional tobacco products (Glynn, 2014). Scientific data are lacking regarding the safety of e-cigarettes. We also do not know if they substitute for the look and feel ofreal cigarettes. Although there is some evidence that e-cigarettes are modestly helpful at helping smokers quit (Bullen et al., 2013), there is other evidence that e-cigarettes may hinder attempts to quit smoking (Al-Delaimy, Myers, Leas, Strong, & Hofstetter, 2015; Kalkhoran & Glantz, 2016). Between 2011 and 2014, e.Jcigarette use by U.S. high school students increased dramatically. Of the 25 percent of high school students reporting any tobacco use, most use e-cigarettes rather than other tobacco products (Arrazola et al., 2015). Recent studies have found that adolescent nonsmokers who try e-cigarettes are more likely to become regular smokers-nicotine addicts-than those who do not (Primack, Soneji, Stoolmiller, Fine, & Sargent, 2015; Wills et al., 2017). QUITTING SMOKING Many people who smoke~ about the health risks and consider quitting or do attempt to quit smoking. Numerous treatment options are available to assist smoking cessation efforts. One widely used method is nicotine replacement therapy, such as smoking e-cigarettes, chewing nicotine gum, or wearing a patch that delivers nicotine (FIGURE 11.14). As mentioned just above, the data suggest that e-cigarettes are not a very effective method for quitting smoking. Prescription medications may also play a part in efforts to quit. Chantix is a drug that acts as a partial agonist for nicotine receptors (recall from Chapter 3 that agonists can mimic the effects of drugs). This action reduces cravings and provides some of the desirable effects of smoking. Wellbutrin is a drug used to treat depression (you will learn more about such drugs in Chapter 15). Wellbutrin also reduces tobacco cravings, although not as strongly as Chantix. A review paper that compared treatments found that Chantix is more effective than nicotine replacement or Wellbutrin (Wu, Wilson, Dimoulas, & Mills, 2006). In addition, numerous behavioral treatments encourage people to quit, teach them effective alternative ways of dealing with stress, and help them try to prevent relapse (Baker et al., 2011). Unfortunately, most people who use these methods do relapse. Only 10-30 percent of people are able to quit smoking over the long term, even in the most effective treatment programs (Schlam & Baker, 2013). In spite of these relatively unimpressive outcomes from treatment studies, millions of people have permanently given up smoking. How did they do it? Around 90 percent of people who successfully quit do so on their own, going "cold turkey" (Smith & Chapman, 2014). Often, some sort of critical event changes the way the smoker thinks about the addiction. The psychologist David Premack provides an example of a man who quit smoking one day because of something that happened when he was picking up his children from the city library: "A thunderstorm greeted him as he arrived there; and at the same time a search of his pockets disclosed a familiar problem: he was out of cigarettes. Glancing back at the library, he caught a glimpse of his children stepping out in the rain, but he continued around the corner, certain that he could find a parking space, rush in, buy the cigarettes and be back before the children got seriously wet" (Pre mack, 1970, p. 115). For the smoker, it was a shocking revelation ofhimself"as a father who would actually leave the kids in the rain while he ran after cigarettes." The man quit smoking on the spot. Researchers have not yet identified the mechanisms that transform critical events into successful smoking cessation (Smith & Chapman, 2014). Because of the difficulty that many people have quitting smoking, much of current research on smoking examines ways to prevent people from smoking in the first place (USDHHS, 2014). What is the primary reason that smokers continue to smoke despite the health consequences? I 11.5 Exercise Has Numerous Benefits In general, the more people exercise, the better their physical and mental health. Those with better fitness in middle age are likely to enjoy much longer lives (Ladenvall et al., 2016). They are less likely to have heart problems (Arem et al., 2015) and are at much lower risk for most types of cancer (Moore et al., 2016). Even weekend warrior types who exercise only once or twice a week show reductions in heart disease and cancer (O'Donovan, Lee, Hamer & Stamatakis, 2017). Scientists do not know exactly how exercise exerts all of its positive effects. Unlike societies throughout most of human history, modern society allows and even encourages people to exert little physical energy. People drive to work, take elevators, spend hours watching remote-controlled television, spend even more hours online, use various labor-saving devices, and complain about not having time to exercise. Once people are out of shape, it is difficult for them to start exercising regularly. Because the modern world requires little physical activity, people need to purposefully exercise during their leisure time. Research clearly shows the benefits of exercise on almost every aspect of our lives, including enhanced memory and enhanced cognition (Harburger, Nzerem, & Frick, 2007). Aerobic exercise-the kind that temporarily increases breathing and heart rate-promotes the growth of new neurons (Carmichael, 2007). The additional neurons created through exercise result in a larger brain, and the brain region that experiences the most growth is the hippocampus (Nokia et al., 2016). As discussed in Chapter 3, the hippocampus is important for memory and cognition. Aerobic exercise is also especially good for cardiovascular health, because it lowers blood pressure and strengthens the heart and lungs (Lavie et al., 2015). A metaanalysis found that exercise is as effective as medications for preventing diabetes or heart disease or promoting recovery following heart attacks (N aci & Ioannidis, 2013). Although the different studies in the meta-analysis varied in the type of physical activity, as well as frequency, intensity, and duration, most included aerobic and muscle strengthening exercises. As little as 10 minutes of exercise can promote feelings of vigor and enhance mood, although at least 30 minutes of daily exercise is associated with the most positive mental state (Hansen, Stevens, & Coast, 2001). In fact, there is compelling evidence that exercise can contribute to positive outcomes for the clinical treatment of depression (Schuch et al., 2016a), as well as being beneficial in the treatment ofaddiction and alcoholism (Read & Brown, 2003). People who are not physically fit are also at greater risk of developing depression (Schuch et al., 2016b; you will learn more about depression in Chapter 14). Fortunately, it is never too late to start exercising and receiving its positive benefits (FIGURE 11.15). In one study, sedentary adults between the ages of60 and 79 were randomly assigned to either six months of aerobic training, such as running or fast dancing, or six months of a nonaerobic control group (Colcombe et al., 2006). Participants in aerobic training significantly increased their brain volume, including both white (myelinated) and gray matter. The nonaerobic control group experienced no comparable changes. In another; study, older adults were assigned randomly to either three months of aerobic exercise or three months of a nonaerobic control group (Emery, Kiecolt-Glaser, Glaser, Malarkey, & Frid, 2005). All the participants agreed to have small cuts made on their bodies so the researchers could study whether aerobic exercise hastened the time it took for the wounds to heal. The wounds of the aerobic group took an average of29.2 days to heal, whereas those of the nonaerobic group took an average of38.9 days to heal. Besides faster healing time, the aerobic group had better cardiorespiratory (heart and lung) fitness. In another study, older adults with memory problems were randomly assigned to an e.?ercise group (3 hours a week for 2 weeks) or to a control group (Lautenschlager et al., 2008). The participants in the exercise group improved in their overall cognition, including memory. The control group showed no changes. The researchers concluded that exercise reduces cognitive decline in older adults with moderate memory problems. Are you an anxious flyer? Like many people, you may be at least somewhat anxious about flying. A statistical expert explained the risk of death from flying this way: "It's once every 19,000 years-and that is only provided the person flew on an airplane once a day for 19,000 years!" ("Six most feared," 2005, p. 5). Other researchers have estimated that 1 in 13 million passengers dies in an airplane crash. What about being the victim of terrorism-do you fear that? In the months following the September 11, 2001, terrorist attacks in the United States, many people avoided flying. Instead, they preferred what they believed to be the safety of driving. Yet after the attacks, the number of people who died in automobile accidents because they chose to drive instead of fly far exceeded the number of people who were killed in the attacks (Gigerenzer, 2004). The more that the press reports crimes and acts of terrorism, the more that people feel they are likely to become the victims of crime or terrorism (Nellis & Savage, 2012). A 2015 Gallup poll found that 51 percent of Americans worry that they or a family member will be the victim of terrorism (FIGURE 11.16). The percentage varies considerably based on media accounts of terrorist incidents. For instance, there tend to be peak worries after well-publicized attacks, such as 9/ 11, the Boston Marathon bombings, and the Paris mass shootings. The 51 percent who worry are greatly overestimating the risk. According to a report from the U.S. Department of State (2012) for the year 2011, 17 American private citizens died as a result of terrorist actions. If we place this number in the context of the ways that people died in the United States during 2011 (Hoyert & Xu, 2012), the comparison means that people in the United States are more than 35,000 times more likely to die from heart disease and 33,000 times more likely to die from cancer than from terrorism. In terms of thinking about their health and well-being, people often fear the wrong things. They tend not to be worried at all about the things that are most likely to kill them. Rare causes of death-not just plane crashes or terrorism, but oddities such as "flesh-eating bacteria" or being murdered while vacationing in a foreign country-are often judged to occur much more frequently than they actually do, while common causes of death are underestimated (Lichtenstein, Slovic, Fischhoff, Layman, & Combs, 1978). People are most likely to die from causes that stem from their own behaviors, which they can learn to modify. For example, heart disease and cancer account for about half of all U.S. deaths (Hoyert & Xu, 2012). Those who suffer from heart disease or cancer are not always to blame for their conditions, but all of us can change our behaviors in ways that may reduce the likelihood of these illnesses (e.g., exercise, eat nutritiously, do not smoke). A report released by the Centers for Disease Control in 2014 indicated that over a quarter ofa million early deaths could be prevented each year if people made better health choices (Yoon et al., 2014). Why do people fear things that are unlikely to harm them but not worry about the things that are truly dangerous? Recall from Chapter 8 the availability heuristic, which refers to believing information that comes most easily to mind. People using this heuristic will judge an event as likely to occur if it is easy to imagine or recall (Slovic, Fischhoff, Lichtenstein, & Roe, 1981). The press widely and dramatically reports plane crashes, as when headlines blazed for weeks after the disappearance of Malaysian Airlines Flight 370 in March 2014. Press reports of other crashes often include vivid pictures or detailed accounts that can readily be recalled or easily imagined. The ease with which people recall this information biases their risk estimates. By contrast, figuring out the risks associated with eating a hamburger and french fries is much more challenging. You would have to know how eating that food would affect your body, such as the likelihood that it would lead to weight gain. You would then need to compute the risk that your particular body weight places you at risk for disease. You would also have to include in your risk prediction your family history, your other risk behaviors, and other lifestyle factors that may be protective. These computations are difficult mental work! It is therefore difficult to look at a hamburger and fries and have the sense of dread that you might experience when you board an airplane. Unless you are willing to hide in your house, you will have a very difficult time protecting yourself from a random act of terrorism. However, you can protect yourself from factors that are more likely to kill you as a student, such as excessive alcohol intoxication, an overdose oflegal or illegal drugs, drinking and driving, or texting while driving. Because of optimism bias, young people also tend to feel invulnerable to many risky behaviors (Radcliffe & Klein, ~002). Yet each year many more college students die from these common behaviors than are killed by rare events such as plane crashes or terrorist ac,,tivity. The biopsychosocial model is central to understanding the difference between the traditional medical model and the approach taken by health psychologists. In the traditional model, the individual is passive. For health psychologists, the individual's thoughts, feelings, and behaviors are central to understanding and improving health. Stress is a basic component of our daily lives. However, stress does not exist objectively, out in the world. Instead, it results directly from the ways we think about events in our lives. For example, some students experience final exams as extremely stressful and often get sick at exam time, whereas other students perceive the same finals as mere inconveniences or even as opportunities to demonstrate mastery of the material. When researchers study stress, then, what are they studying? j 11.7 Stress Is a Response to Life Events Stress is a type of response that typically involves an unpleasant state, such as anxiety or tension. A stressor is something in the environment that is perceived as threatening or demanding and therefore produces stress. One person's stressor, such as having to speak in front of a crowd, may be another person's cherished activity. Stress elicits a coping response, which is an attempt to avoid, escape from, or minimize the stressor. When too much is expected of us or when events are worrisome or scary, we perceive a discrepancy between the demands of the situation and our resources to cope with them. That discrepancy might be real, or we might be imagining it. In general, positive and negative life changes are stressful. Think about the stresses of going to college, getting a job, marrying, being fired, losing a parent, winning a major award, and so on. The greater the number of changes, the greater the stress, and the more likely the stress will affect physiological states. Stress is often divided into two types: Eustress is the stress of positive events. For example, you might experience eustress when you are admitted to the college you really want to attend or when you are preparing for a party you are looking forward to. Distress is the stress of negative events. For example, you might experience distress when you are late for an important meeting and become trapped in traffic or when you are helping a loved one deal with a serious illness. Most people use the term stress only in referring to negative events, but both distress and eustress put strains on the body. The number of stressful events a person experiences, whether they are negative or positive, predicts health outcomes. Some events are more stressful than others, of course ( FIGURE 11.17). One team of researchers assigned point values to 43 different life events. For instance, the death of a spouse was 100 points, pregnancy was 40 points, and a vacation was 13 points (Holmes & Rahe, 1967). A person's stress level could be determined by adding up the points for every event the person had experienced in the previous year. Someone who had b~en married, moved, started a new job, had a child, and had a change in sleeping pattern during the previous year would score very high on this scale and therefore be likely to suffer poor health as a result. A version of the scale for students can be found in TABLE 11.2. Psychologists typically think of stressors as falling into two categories: major life stressors and daily hassles. Major life stressors are changes or disruptions that strain central areas of people's lives (Pillow, Zautra, & Sandler, 1996). Major life stressors include choices made by individuals, not just things that happen to them. For instance, some parents report that having their first child is one of the most joyful-but also one of the most taxing-experiences of their lives. Nonetheless, research has shown that unpredictable and uncontrollable catastrophic events-such as floods, earthquakes, or wars-are especially stressful (Kanno et al., 2013; Tang, 2007). To avoid serious health problems, combat soldiers and others in prolonged stressful situations often must use combinations of strategies to cope with the stress of their situations. Coping strategies are discussed in Section 11.12. Daily hassles are small, day-to-day irritations and annoyances, such as driving in heavy traffic, dealing with difficult people, or waiting in line. Daily hassles are stressful, and their combined effects can be comparable to the effects of major life changes (DeLongis, Folkman, & Lazarus, 1988). Because these low-level irritations are ubiquitous, they pose a threat to coping responses by slowly wearing down personal resources. Studies that ask people to keep diaries of their daily activities find consistently that the more intense and frequent the hassles, the poorer the physical and mental health of the participant (Almeida, 2005). People may habituate to some hassles but not to others. For example, conflicts with other people appear to have a cumulative detrimental effect on health and well-being. Living in poverty or in a crowded, noisy, or polluted place also can have cumulative detrimental effects on health and well-being (Santiago, Wadsworth, & Stump, 2011). Researchers have a good understanding of the biological mechanisms that underlie the stress response. A stressor activates two systems: a fast-acting sympathetic nervous system response and a slower-acting response resulting from a complex system ofbiological events known as the hypothalamic-pituitary-adrenal (HPA) axis. Stress begins in the brain with the perception of some stressful event. For our very distant ancestors, the event might have been the sight of a predator approaching rapidly. For us, it is more likely to be an approaching deadline, a stack of unpaid bills, a fight, an illness, and so on. The hypothalamus first activates the sympathetic nervous system, which activates the adrenal glands-located on top of the kidneysto release epinephrine and norepinephrine, increasing heart rate, blood pressure, and respiration and making the body ready for action (see Chapter 3, "Biology and Behavior"). Meanwhile, in the HPA axis (FIGURE 11.18), the hypothalamus sends a chemical message to the pituitary gland, a major gland located at the base of the brain. In turn, the pituitary gland sends a hormone that travels through the bloodstream and eventually also reaches the adrenal glands (although a different region of the gland than the faster system). The adrenals then secrete cortisol. Cortisol circulates throughout the body and to various brain areas, especially the hypothalamus, hippocampus, and amygdala (De Kloet, Joels, & Holsboer, 2005). In turn, cortisol increases the amount of glucose in the bloodstream. All of these actions help the body prepare to respond to the stressor. For example, the response might consist of fighting an attacker. Because hormones have long-lasting effects, stress affects organs after the stressor has been removed. Studies of stress show that, in human and nonhuman animals, excessive stress disrupts working memory, an effect that is especially noticeable when the demands on working memory are high (Oei, Everaerd, Elzinga, Van Well, & Bermond, 2006; Otto, Raio, Chiang, Phelps, & Daw, 2013). Chronic stress has also been associated with long-term memory impairments (McEwen, 2016). Excessive cortisol damages neurons in brain areas such as the hippocampus, which is important for storing long-term___memories (Sapolsky, 1994). Stress also interferes with the ability to retrieve information from longterm memory (Finsterwald & Alberini, 2014). Early childhood stress is a risk factor for developing psychological disorders later in life (Heim, Newport, Mletzko, Miller, & Nemeroff, 2008). Emerging research suggests the possibility that stress experienced by mothers may be passed along to their offspring through epigenetics (genetic changes discussed in Chapter 3, "Biology and Behavior"). In one study, rats were exposed to unpredictable stress that led to physiological changes in their brains. These rats were mated 14 days later and subsequently had offspring. When those offspring became adults they showed abnormalities in fear learning and heightened physiological responses to stress (Zaidan, Leshem, & Gaisler-Salomon, 2013). Through epigenetics, the effect of stress on mothers also leads to altered social behaviors in their offspring (Franklin, Linder, Russig, Thony, & Mansuy, 2011). Thus, highly stressful experience Kidneys FIGURE 11.18 hypothalamic-pituitary-adrenal (HPA) axis A body system involved in stress responses. interpreted by ' Various bra:] areas -- t Hormones Adren~ glan.'.::,__J l Cortisol __ ___, can affect behavior across generations (Bohacek, Gapp, Hypothalamic-Pituitary-Adrenal (HPA) Axis Saab, & Mansuy, 2013; Turecki & Meaney, 2016). GENERAL ADAPTATION SYNDROME In the early 1930s, the endocrinologist Hans Selye began studying the physiological effects of sex hormones by injecting rats with hormones from other animals. The result was damage to a number of bodily systems. Surmising that the foreign hormones must have caused this damage, Selye conducted further tests. He tried different types of chemicals, and he even physically restrained the animals to create stressful situations. Selye found that each manipulation produced roughly the same pattern of physiological changes: enlarged adrenal glands, decreased levels of lymphocytes-specialized white blood cells-in the blood, and stomach ulcers. The decreased lymphocytes result from damage to part of the immune system (discussed more fully in Section 11.10). Together, the enlarged adrenal glands and damage to the immune system reduce the organism's potential ability to resist additional stressors. Selye concluded that these responses are the hallmarks of a nonspecific stress response. He called this pattern the general adaptation syndrome (Selye, 1932). The general adaptation syndrome consists of three stages: alarm, resistance, and exhaustion (FIGURE 11.19). The alarm stage is an emergency reaction that prepares the body to fight or flee (it is identical to Walter Cannon's fight-or-flight response, discussed in Section 11.9). Physiological responses, such as the release of cortisol and epinephrine, are aimed at boosting physical abilities while reducing activities that make the organism vulnerable to infection after injury. There is a briefreduction in stress resistance during this stage, when the body is most likely to be exposed to infection and disease. The immune system kicks in, and the body begins fighting back. During the resistance stage, the body prepares for longer, sustained defense from the stressor. Immunity to infection and disease increases somewhat as the body maximizes its defenses. When the body reaches the exhaustion stage, various physiological and immune systems fail. Body organs that were already weak before the stress are the first to fail. These various perspectives show that short-term stress produces adaptive responses to the demands of daily living. Prolonged or overwhelming stress, however, impairs health, which we consider in the next section. From an evolutionary perspective, the ability to deal effectively with stressors is important to survival and reproduction. The physiological and behavioral responses that accompany stress help mobilize resources to deal with danger. The physiologist Walter Cannon (1932) coined the term fight-or-flight response to describe the physiological preparation of animals to deal with an attack (FIGURE 11.20). Within seconds, the sympathetic nervous system's response to a stressor enables the organism to direct all energy to dealing with the threat at hand. Our ancestors needed that energy for either outrunning a charging predator or standing their ground and fighting it. (Either response causes further stress.) The physical reaction includes increased heart rate, redistribution of the blood supply from skin and viscera (digestive organs) to muscles and brain, deepening of respiration, dilation of the pupils, inhibition of gastric secretions, and an increase in glucose released from the liver. Less critical autonomic activities such as food digestion, which can occur after the stressor is removed, are postponed. (The autonomic nervous system is described in more detail in Chapter 3.) At the same time, activation of the HPA axis helps prepare a prolonged response. The generalizability of the fight-or-flight response has been questioned by Shelley Taylor and colleagues (Taylor, 2006; Taylor et al., 2002). They argue that because the vast majority of human and nonhuman animal research has been conducted using males (females represent fewer than 1 in 5 of the participants), the results have distorted the scientific understanding ofresponses to stress. The exclusion of females from these early studies has many possible explanations. For example, researchers often use rats in heart disease studies that cannot be conducted with humans because the research might increase participants' risk of heart disease, and most rat studies use male rats to avoid complications that may be caused by female hormonal cycles. Similarly, most researchers have avoided using women in their studies of responses to stress because female menstrual patterns might make women more difficult to study. That is, women's responses could be mediated by (influenced by) fluctuations in circulating hormones that vary over the menstrual cyd:le. The result is a sex inequality in laboratory stress studies. This research bias can blind us to the fact that women and men often respond differently to stressors. Taylor and colleagues argue that, in very general terms, females respond to stress by protecting and caring for their offspring, as well as by forming alliances with social groups to reduce risks to individuals, including themselves. They coined the phrase tend-and-befriend response to describe this pattern (FIGURE 11.21). Laboratory research supports the idea that stressed women are more attentive to infant distress than are stressed men (Probst et al., 2017). Tend-and-befriend responses make sense from an evolutionary perspective. Females typically bear a greater responsibility for the care of offspring, and responses that protect their offspring as well as themselves would be maximally adaptive. When a threat appears, quieting the offspring and hiding may be more effective means of avoiding harm than trying to flee while pregnant or with a clinging infant. Furthermore, females who selectively affiliate with others, especially other females, might acquire additional protection and support. The tend-and-befriend stress response is an excellent example of how thinking about psychological mechanisms in view of their evoluti_onary significance may lead us to question long-standing assumptions about how the mind works. Females who respond to stress by nurturing and protecting their young and by forming alliances with other females apparently have a selective advantage over those who fight or flee, and thus these behaviors would pass to future generations. Oxytocin, a hormone important for mothers in bonding to newborns (see Chapter 9's discussion of the chemistry of attachment), is produced in the hypothalamus and released into the bloodstream through the pituitary gland. Recent research has shown that oxytocin levels tend to be high for women-but not men-who are socially distressed. Although oxytocin exists naturally in men and women, it seems especially important in women's stress response. Thus, it provides a possible biological basis for the tend-and-befriend response to stress exhibited (mainly) by women (Taylor, 2006). A great deal of research is currently being conducted on the role of oxytocin during stress responses. According to one recent hypothesis, it is possible that the release of oxytocin during social stress encourages women to affiliate with, or befriend, others (Taylor, Saphire-Bernstein, & Seeman, 2010). In terms of evolution, why might women be more likely to respond to stress with tend-and-befriend than fight-or-flight? \ How Does Stress Affect Health? Although stress hormones are essential to normal health, over the long term they negatively affect health. Some stress is good for health, but too much is bad. People who have very stressful jobs-such as air traffic controllers, combat soldiers, and firefighters-tend to have many health problems that presumably are due partly to the effects of chronic stress. There is overwhelming evidence that chronic stress, especially psychosocial stress, is associated with the initiation and progression of a wide variety of diseases, from cancer to AIDS to cardiac disease ( Cohen, Janicki-Deverts, & Miller, 2007; McEwen & Gianaros, 2011; Thoits, 2010). In addition, many people cope with stress by engaging in damaging behaviors. For instance, the number one reason that problem drinkers give for abusing alcohol is to cope with distress in their lives. When people are stressed, !hey drink, smoke cigarettes, eat junk food, use drugs, and so on (Baumeister, Heatherton, & Tice, 1994). As discussed in Section 11.1, most of the major health problems in industrialized societies are partly attributable to unhealthful behaviors, many of which occur when people feel stressed. Let's examine the specific effects of stress on health. I 11.10 Stress Disrupts the Immune System One ofSelye's central points was that stress alters the functions of the immune system. The immune system is the body's mechanism for dealing with invading microorganisms, such as allergens, bacteria, and viruses. Normally, when these foreign substances enter the body, the immune system launches into action to destroy the invaders. Stress interferes with this natural process. At the time that Selye developed his theory, it was not known that a type of bacteria is the major cause of ulcers (Marshall & Warren, 1984). Although he thought another mechanism was at work, a less active immune system can account for the increased number of stomach ulcers. For example, bacteria can cause stomach ulcers when the immune system is less active due to stress (Levenstein, Ackerman, Kiecolt-Glaser, & Dubois, 1999). The field of psychoneuroimmunology studies the response of the body's immune system topsychological variables. More than 300 studies have demonstrated that short-term stress boosts the immune system, whereas chronic stress weakens it, leaving the body less able to deal with infection (Segerstrom & Miller, 2004). The immune system is made up of three types of specialized white blood cells known as lymphocytes: B cells, T cells, and natural killer cells. B cells produce antibodies, protein molecules that attach themselves to foreign agents and mark them for destruction. Some types of B cells are able to remember specific invaders, making for easier identification in the future. For this reason, you have lifelong immunity to some diseases once you have been exposed to them naturally or through inoculation. The T cells are involved in attacking the intruders directly and also with increasing the strength of the immune response. Note that these so-called helper cells are incapacitated by infection with human immunodeficiency virus (HIV), which eventually leads to the immune disorder AIDS. Natural killer cells are especially potent in killing viruses and also help attack tumors. Brief stressors, including final exams, decrease the ability of white blood cells (Kiecolt-Glaser & Glaser, 1991) and natural killer cells (Kang, Coe, McCarthy, & Ershler, 1997) to fight off infection. The body heals more slowly when people are stressed than when not stressed (Kiecolt-Glaser, Page, Marucha, MacCullum, & Glaser, 1998). The detrimental effects oflong-term stress on physical health are due partly to decreased lymphocyte production. This decrease renders the body less capable of warding off foreign substances. Adding insult to injury, the immune systems of those who tend to be particularly anxious (Maes et al., 2002) or who are already juggling a bunch of other daily hassles (Marshall et al., 1998) tend to be especially vulnerable. Some of the behaviors that stressed-out college students may engage in-such as smoking cigarettes, drinking alcohol, and skipping slee1p- further damage the immune system, making them vulnerable to illness or infection (Glaser & Kiecolt-Glaser, 2005). In a particularly clear demonstration that stress affects the immune system, Sheldon Cohen and colleagues (1991) paid healthy volunteers to have cold viruses swabbed into their noses. Those who reported the highest levels of stress before being exposed to the cold viruses developed worse cold symptoms and higher viral counts than those who reported being less stressed (see "The Methods of Psychology: Cohen's Study of Stress and the Immune System"). (Surprisingly, behaviors such as smoking, maintaining a poor diet, and not exercising had very small effects on the incidence of colds.) Apparently, when the underlying physiological basis of the stress response is activated too often or too intensely, the functioning of the immune system is impaired, and the probability and severity of ill health increase (Herbert & Cohen, 1993; McEwen, 2008). In a study that looked specifically at the effects of desirable and undesirable events on the immune system, participants kept daily diaries for up to 12 weeks (Stone et al., 1994). In the diaries, they recorded their moods and the events in their lives. They rated the events as desirable or undesirable. Each day, the participants took an antigen, a substance- in this case a protein from a rabbit- that their immune systems recognized as a threat and therefore formed antibodies against. Then the participants provided saliva samples so the researchers could examine their antibody responses. The more desirable events a participant reported, the greater the antibody production. Similarly, the more undesirable events reported, the weaker the antibody production. The effect of a desirable event on antibodies lasted for two days. These and subsequent findings provide substantial evidence that perceived stress influences the immune system. Although short-term stressors appear to boost immune Coronary heart disease is the leading cause of death for adults in the industrialized world. According to a World Health Organization report in 2011, each year more than 7 million people die from heart attacks (FIGURE 11.22). Even though the rate of heart disease is lower in women than in men, heart disease is the number one killer of women. Genetics is among the many factors that determine heart disease, but two extremely important determinants are health behaviors (such as bad eating habits, smoking, and lack of exercise) and a small number of personality traits related to the way people respond to stress. TYPE A/BAND HEART DISEASE One of the earliest tests of the hypothesis that personality affects coronary heart disease was conducted by the Western Collaborative Group, in San Francisco (Rosenman et al., 1964). In 1960, this group of physicians began an 8½-year study. The participants were 3,500 men from northern California who were free of heart disease at the start of the study. The men were screened annually for established risk factors such as high blood pressure, accelerated heart rate, and high cholesterol. Their overall health practices were assessed. Personal details-such as education level, medical and family history, income, and personality traitswere also assessed. The results indicated that a set of personality traits predicted heart disease. This set of traits is now known as the Type A behavior pattern. Type A describes people who are competitive, achievement oriented, aggressive, hostile, impatient, and time-pressed (feeling hurried, restless, unable to relax; FIGURE 11.23). Men who exhibited these traits were much more likely to develop coronary heart disease than were those who exhibited the Type B behavior pattern. Type B describes noncompetitive, relaxed, easygoing, accommodating people. In fact, this study found that a Type A personality was as strong ~ predictor of heart disease as was high blood pressure, high cholesterol, or smoking (Rosenman et al., 1975). Although the initial work was done only with men, subsequent research shows that these conclusions apply to women as well (Knox, Weidner, Adelman, Stoney, & Ellison, 2004; Krantz & McCeney, 2002). FIGURE 11.22 Heart Disease Awareness To increase people's awareness of this growing problem, countries, cities, and local agencies use public service campaigns such as this one. HOSTILITY AND HEART DISEASE More recently, research has shown that only certain components of the Type A behavior pattern are related to heart disease. The most toxic factor on the list is hostility. Hot-tempered people who are frequently angry, cynical, and combative are much more likely to die at an early age from heart disease (Eaker, Sullivan, Kelly-Hayes, D'Agostino, & Benjamin, 2004). Indeed, having a high level of hostility while in college predicts greater risk for heart disease later in life (Siegler et al., 2003). There is also considerable evidence that negative emotional states not on the list, especially depression, predict heart disease ( Carney & Freedland, 2017). Of course, having a heart condition might make people hostile and depressed. Still, having a hostile personality and being depressed also predicted the worsening of heart disease, so causes and effects might be connected in a vicious cycle. The evidence across multiple studies with different indices of disease and markers for the early development of disease is clear: Hostile, angry people are at greater risk for serious diseases and earlier death than are those with more optimistic and happier personalities. This conclusion appears to be universal. For example, a crosscultural comparative study of college students replicated the association of anger and impatience with a wide range of health symptoms for students from all ethnic and cultural groups (Nakano & Kitamura, 2001). "TYPE. :Z.. BE~AVIOR. In contrast, optimistic people tend to be at lower risk for heart disease (Maruta, Colligan, Malinchoc, & Offord, 2002). Learning to manage both stress and anger improves outcomes for those who have heart disease (Sirois & Burg, 2003). Later in this chapter, you will find many suggestions for managing stress. FIGURE 11.24 Heart Disease in Close-Up PHYSIOLOGICAL EFFECTS OF STRESS ON THE HEART Beingstressedorfeeling negative emotions can cause heart problems in three ways. First, people often cope with these states through behaviors that are bad for health. Second, some personality traits, such as hostility and depression, have negative effects on people's social networks and on any support they may provide against stress (Jackson, Kubzansky, Cohen, Jacob, & Wright, 2007). Third, negative personality traits and stress can produce direct physiological effects on the heart. The heart pumps nearly 2,000 gallons of blood each day, on average beating more than 100,000 times. A vast network of blood vessels carries oxygen and nutrients throughout the body. As people age, the arteries that supply the heart and those leading from the heart become narrow due to the build up of fatty deposits, known as plaque, and become stiff This narrowing raises the pressure against which the heart has to pump, making the heart work harder and eventually leading to coronary heart disease (FIGURE 11.24). Like aging, stress decreases blood flow by making blood vessels less able to dilate. Even doing a simple stress test, in which the participants only have to push buttons quickly in response to particular colored lights, reduces by 50 percent the ability of blood vessels to expand, and this effect lasts for 45 minutes (Spieker et al., 2002). Blocking cortisol production prevents this dysfunction, suggesting a mechanism by which stress contributes to coronary heart disease and sudden cardiac death (Broadley et al., 2005). Over time, stress causes wear and tear on the heart, making it more likely to fail. Chronic stress leads to overstimulation of the sympathetic nervous system, causing higher blood pressure, constriction of blood vessels, elevated levels of cortisol, increased release of fatty acids into the bloodstream, and greater buildup of plaque on arteries. In turn, each of these conditions contributes to heart disease. For these reasons, people who tend to be stressed out Over time, plaque naturally builds up in the blood vessels are more likely to have heart disease than are people who tend to around the heart, decreasing the heart's ability to function. be laid-back. Think about a time when you were very angry with someone. How did it feel to be so angry? Your body responded by increasing your heart rate, shutting down digestion, moving more blood to your muscles. In short, your body acted as though you were preparing to fight or run away. You may have seen someone turn red with anger or start to shake. People with hostile personalities frequently experience such physiological responses, and these responses take a toll on the heart. Chronic hostility can lead to the sdme physical symptoms as chronic stress. Over time, then, being hostile or angry causes wear and tear on the heart, making the heart more likely to fail. What personality characteristics place people most at risk for developing heart disease? I 11.12 Coping Reduces the Negative Health Effects of Stress We all experience stressful events. To deal effectively with the stressors in our lives, we use cognitive appraisals that link feelings with thoughts. Cognitive appraisals enable us to think about and manage our feelings more objectively. Richard Lazarus (1993) conceptualized a two-part appraisal process: People use primary appraisals to primary appraisals Part of the coping process that involves making decisions about whether a stimulus is stressful, benign, or irrelevant. secondary appraisals Part of the coping process during which people evaluate their response options and choose coping behaviors. uo1ssaJdap pue 'Jaflue 'Al!l!JS04 flu1pnpu1 'sa1e1s 1euoqowa aAqeflau =H3MSN\f emotion-focused coping A type of coping in which people try to prevent having an emotional response to a stressor. problem-focused coping A type of coping in which people take direct steps to confront or minimize a stressor. decide whether stimuli are stressful, benign, or irrelevant. If the stimuli are deter- (a) mined to be stressful, people use secondary appraisals to evaluate response options and choose coping behaviors. Such cognitive appraisals also affect perceptions of potential stressors and reactions to stressors in the future. In other words, making cognitive appraisals can help people prepare for stressful events or downplay them. Coping that occurs before the onset of a future stress or is called anticipatory coping. For example, when parents are planning to divorce, they sometimes rehearse how they will tell their children. TYPES OF COPING Susan Folkman and Richard Lazarus (1988) have grouped coping strategies into two general categories: emotion-focused coping and problemfocused coping. In emotion-focused coping, a person tries to prevent an emotional response to the stressor (FIGURE 11.25A). That is, the person adopts strategies, often (b) passive, to numb the pain. Such strategies include avoidance, minimizing the problem, trying to distance oneself from the outcomes of the problem, or engaging in behaviors such as eating or drinking. For example, if you are having difficulty at school, you might avoid the problem by skipping class, minimize the problem by telling yourself school is not all that important, distance yourself from the outcome by saying you can always get a job if college does not work out, or overeat and drink alcohol to dull the pain of the problem. These strategies do not solve the problem or prevent it from recurring in the future. By contrast, problem-focused coping involves taking direct steps to solve the problem: generating alternative solutions, weighing their costs and benefits, and choosing between them (FIGURE 11.25B). In this case, if you are having academic trouble, you might think about ways to alleviate the problem, such as arranging for a tutor or asking for an extension for a paper. Given these alternatives, you could consider how likely a tutor is to be helpful, discuss the problem with your professors, and so on. People adopt problem-focused behaviors when they perceive stressors as controllable and are experiencing only moderate levels of stress. Conversely, emotion-focused behaviors may enable people to continue functioning in the face of uncontrollable stressors or high levels of stress. The best way to cope with stress depends on personal resources and on the situation. Most people report using both emotion-focused coping and problem-focused coping. Usually, emotion-based strategies are effective only in the short run. For example, if your partner is in a bad mood and is giving you a hard time, just ignoring him or her until the mood passes can be the best option. In contrast, ignoring your partner's drinking problem will not make it go away, and eventually you will need a better coping strategy. Problem-focused coping strategies work, however, only if the person with the problem can do something about the situation. POSITIVE REAPPRAISAL Susan Folkman and Judith Moskowitz (2000) have demonstrated that, in addition to problem-focused coping, three strategies can help people use positive thoughts to deal with stress. Positive reappraisal is a cognitive process in which a person focuses on possible good things in his or her current situation. That is, the person looks for the proverbial silver lining. Another strategy is to make a downward comparison, comparing oneself to those who are worse off. This kind of comparison has been shown to help people cope with serious illnesses. Finally, creation of positive events is a strategy of giving positive meaning to ordinary events. If you were diagnosed with diabetes (discussed briefly in Chapter 10), you could use all three strategies. You could focus on how having diabetes will force you to eat a healthy diet and exercise regularly (positive reappraisal). You could recognize that diabetes is not as serious as heart disease (downward comparison). You could take joy in everyday activities (creation of positive events). For example, riding a bike, watching the sunset, or savoring a recent compliment might help you focus on the positive aspects of your life and deal with your negative stress. INDIVIDUAL DIFFERENCES IN COPING People differ widely in their perceptions of how stressful life events are. Some people seem stress resistant because they are so capable of adapting to life changes by viewing events constructively. Suzanne Kobasa (1979) has named this personality trait hardiness. According to Kobasa, hardiness has three components: commitment, challenge, and control. People high in hardiness are committed to their daily activities, view threats as challenges or as opportunities for growth, and see themselves as being in control of 1'VE BEEN VER'O I kNOW THAT MY EXPEIUENCE OF CONSCIOUSN ESS IS 1"HE SAME AS OTHEl~'s want from life, and who can listen and provide advice, assistance, or simply encouragement. Trusting others is a necessary part of social support, and it is associated with positive health outcomes. Consider your spiritual life. If you have spiritual beliefs, try incorporating them into your daily living. Benefits can accrue from living a meaningful life and from experiencing the support provided WHf\T IS MY PURPOSE? I I \ ' I EXPERIENCES of , ' cotlSCIOUSN[ SS? Wt!'( ARE WE HERE? wMIIT IS THE ~EAl'IING- OF LIFE? ,. _, G COMPLEX CARBOHYDRATES CHAPTER 11 HEALTH AND WELL-BEING by faith communities.  Try some happiness exercises. Each of the following exercises may enhance your happiness by helping you focus on positive events and more-positive explanations of troubling events (Lyubomirsky, King, & Diener, 2005). 1. In the next week, write a letter of gratitude and deliver it in person to someone who has been kind to you but whom you have never thanked. 2. Once a week, write down three things that went well that day and explain why they went well. 3. Tell a friend about a time when you did your very best, and then think about the strengths you displayed. Review this story every night for the next week. 4. Imagine yourselflO years in the future as your best possible self, as having achieved all your most important goals. Describe in writing what your life is like and how you got there. 5. Keep a journal in which you write about the positive aspects of your life. Reflect on your health, freedom, friends, and so on. 6. Act like a happy person. Sometimes just going through the motions of being happy will create happiness. Activities such as these are called "shotgun interventions" because they are fast acting, cover a broad range ofbehaviors, have relatively large effects for such a small investment, and pose little risk. However, the long-term effects of the interventions are unknown.