2 Module 32: Basic Motivation Concepts, and Hunger
3 MotivationMotivation refers to a need or desire that energizes behavior and directs it towards a goal.For example, Aron Ralston found the motivation to cut off his own arm when trapped on a cliff in Utah in What motivated him to do this? Hunger? The drive to survive? The drive to reproduce?In Utah’s narrow Bluejohn Canyon, just 150 yards above his final rappel, Ralston, after thinking he had no way to survive, had a dream of a one-armed man picking up a young boy. Maybe this stirred up his desire to live to be a father someday. [His first child, Leo, was born in 2010.]
4 Perspectives on Motivation There are different ways of thinking of the way motivation works, all of which relate to the “push” of biological processes and the “pull” of culture, social forces, and ideals.Instinct Theory Evolutionary PerspectiveDrive-Reduction TheoryArousal [Optimization] TheoryHierarchy of Needs/MotivesNo animation.
5 Do Instincts Direct Human Behavior? An instinct is a fixed (rigid and predictable) pattern of behavior that is not acquired by learning and is likely to be rooted in genes and the body.Instinctive behaviors are common in other species. Newly hatched ducks and geese form attachments to the first moving object they see. Humans may have a general nesting “instinct,” but the specific behavior is less predictable. The bird can only build one kind of nest, but humans may decorate a baby’s room in a variety of ways, or use this general “instinct” to simply buy and repair a home.Although instinct theory failed to explain most human motives, the underlying assumption that genes predispose species-typical behavior remains as strong as ever. Psychologists may apply this perspectiveHuman “nesting” behaviorInstinctual nesting
6 Instincts Evolutionary Perspective Other species have genetically programmed instincts “motivating” their actions.Do humans?Human babies show certain reflexes, but in general, our behavior is less prescribed by genetics than other animals.We may, however, have general patterns of behavior which can be explained as emerging through natural selection.Instinct theory has given way to evolutionary theory in explaining human behavior.Click to reveal bullets.
7 Drive ReductionA drive is an aroused/tense state related to a physical need such as hunger or thirst.Drive-reduction theory refers to the idea that humans are motivated to reduce these drives, such as eating to reduce the feeling of hunger. This restores homeostasis, a steady internal state.The physiological aim of drive reduction is homeostasis—the maintenance of a steady internal state. An example of homeostasis (literally “staying the same”) is the body’s temperature-regulation system, which works like a room thermostat. Both systems operate through feedback loops.Not only are we pushed by our need to reduce drives, we also are pulled by incentives—positive or negative environmental stimuli that lure or repel us. Depending on our learning, the aroma of good food, whether fresh roasted peanuts or toasted ants, can motivate our behavior. So can the sight of those we find attractive or threatening. When there is both a need and an incentive, we feel strongly driven
8 Seeking Optimum Arousal Some behavior cannot be easily connected to a biological need, and instead seems driven by a need to either increase or decrease our physiological arousal level.Curiosity, as with kids and these monkeys, may be a way of increasing stimulation to reach an optimum arousal level.Click to reveal bullets.It seems that curiosity can be considered a basic need or drive to get to know one’s environment to improve the chances of survival. However, in this model, curiosity is seen as a way of seeking an optimum arousal level.People with ADHD seem to seek stimulation for this reason; it increases dopamine levels almost as well as Ritalin, although the pursuit of such stimulation, even by fidgeting, can be disruptive.It is not clear that the curiosity of scientists, though, serves to increase physiological arousal.
9 Arousal Theory of Motivation My brother, Mike is a thrill seeker! My brother, Mike, is always looking for the next “adrenaline” rush and had me pacing back and forth while he took my seven year old daughter diving under waves in the ocean. Arousal theory of motivation would explain that he is more interested in thrill seeking than I am because his optimal level of arousal is higher than mine.
10 Hierarchy of Needs/Motives In 1943, Abraham Maslow proposed that humans strive to ensure that basic needs are satisfied before they find motivation to pursue goals that are higher on this hierarchy.Near the end of his life, Maslow proposed that some people also reach a level of self-transcendence. At the self-actualization level, people seek to realize their own potential. At the self-transcendence level, people strive for meaning, purpose, and communion that is beyond the self, that is transpersonal .
11 Violating the Hierarchy? Do hunger strikers and mystics feel secure enough in meeting their needs that they can do without food temporarily to pursue a higher goal?Soldiers sacrifice safety, but could they be seen as fighting for safety, both indirectly (protecting the country) and directly (defeating the people shooting at them)?Violating the Hierarchy?No animation.
12 After spending years in the ocean, a mature salmon swims up its home river to return to its birthplace. This behavior is an example of:A. homeostasis.B. a set point.C. a refractory period.D. an instinct.Answer: D MODULE 32 Basic Motivational Concepts and Hunger
13 A closer look at one need/motive: Hunger Research on hunger is consistent with Abraham Maslow’s hierarchy:In one study, men whose food intake had been cut in half became obsessed with food.Hunger even changes our motivations as we plan for the future.Ancel Keys and his research team (1950) studied semistarvation by cutting the food intake of 36 male volunteers—all wartime conscientious objectors—in half. Without thinking about it, the men began conserving energy; they appeared listless and apathetic. After dropping, their body weights eventually stabilized at about 25 percent below their starting weights.
14 Physiology of HungerExperiments and other investigations show a complex relationship among the stomach, hormones, and different parts of the brain.Feeling hungry causes stomach contractions, but the feeling can happen even if the stomach is removed or filled with a balloon.Click to reveal bullets.
15 The Hypothalamus and Hunger Receptors throughout the digestive system monitor levels of glucose and send signals to the hypothalamus in the brain.The hypothalamus then can send out appetite-stimulating hormones, and later, after eating, appetite-suppressing hormones.Increases in the hormone insulin (secreted by the pancreas) diminish blood glucose, partly by converting it to stored fat. If your blood glucose level drops, your brain will monitor the level and trigger hunger.
16 The Body Talks Back to the Brain Hormones travel from various organs of the body to the brain (the hypothalamus) to convey messages that increase or decrease appetite.During bypass surgery for severe obesity, surgeons seal off part of the stomach. The remaining stomach then produces much less ghrelin, and the person’s appetite lessens (Lemonick, 2002). Scientists hope to develop drugs (patches, or nose sprays) that would manipulate the levels of hormones such as Leptin, which suppresses hunger.
17 When scientists put 36 conscientious objectors on a semi-starvation diet for six months, all of the following occurred EXCEPT:A. the men appeared listless and apathetic.B. the men became obsessed with food.C. the men spent more time thinking about sex.D. the men lost interest in social activities.Answer: C MODULE 32 Basic Motivational Concepts and Hunger
18 In a classic experiment, obese patients whose daily caloric intake was dramatically reduced lost only 6 percent of their weight. This limited weight loss was due, at least in part, to the fact that their dietary restriction led to:A. a proliferation of their lymphocytes.B. the inhibition of their dopamine reuptake.C. a sharp decrease in their metabolic rates.D. a dramatic surge in their cholesterol levels.Answer: C MODULE 32 Basic Motivational Concepts and Hunger
19 Regulating WeightWhen a person’s weight drops or increases, the body responds by adjusting hunger and energy use to bring weight back to its initial stable amount.Most mammals, without consciously regulating, have a stable weight to which they keep returning. This is also known as their set point.A person’s set point might rise with age, or change with economic or cultural conditions. Therefore, this “set point” of stable weight is more of a current but temporary “settling point.”By the end of their 6 months of semistarvation, the men who participated in Keys’ experiment had stabilized at three-quarters of their normal weight, while taking in half of their previous calories. They managed this by reducing their energy expenditure, partly through inactivity but partly because of a 29 percent drop in their basal metabolic rate.Slow, sustained changes in body weight can alter one’s set point. Yo-yo dieting doesn’t work!Given unlimited access to a wide variety of tasty foods, people and other animals tend to overeat and gain weight
20 Which foods to eat? Taste Preferences Some taste preferences are universal. Carbohydrates temporarily raise levels of serotonin, reducing stress and depression.Other tastes are acquired and become favorites through exposure, culture, and conditioning.Different cultures encourage different tastes.Our preferences for sweet and salty tastes are genetic and universal.Some cultures find these foods to be delicious: reindeer fat and berries, or roasted guinea pig.
21 Biology, Evolution, and Taste Preferences Differences in taste preferences are not arbitrary. Personal and cultural experience, influenced by biology, play a role.We can acquire a food aversion after just one incident of getting sick after tasting a food.It is adaptive in warm climates to develop a taste for salt and spice, which preserve food.Disliking new tastes may have helped to protect our ancestors.Forcing children to try new foods multiple times might make sense. Their first aversion to a food is a biologically protective reaction but it does not predict whether they will eventually like it.
22 How much do we eat? Eating depends in part on situational influences. Social facilitation: the presence of others accentuates our typical eating habitsUnit bias: we may eat only one serving/unit (scoop, plateful, bun-full) of food, but will eat more if the serving size is largerBuffet effect: we eat more if more options are availableWhen offered a supersized standard portion, people put away more calories. Another research team led by Brian Wansink (2006, 2007) invited people to help themselves to ice cream. They, too, found a unit bias: Even nutrition experts took 31 percent more when given a big rather than small bowl, and 15 percent more when scooping it with a big scoop rather than a small one.
23 Influences on Eating Behavior The idea of “motivation” can be complex when it comes to the case of a desire to eat a particular food.
24 Obesity refers to an amount of body fat that increases the risk of health problems to the point that weight loss is a health priority.Obesity is linked to diabetes, heart problems, arthritis, and some cancers.The adult obesity rate has more than doubled in the last 40 years, reaching 34 percent, and child-teen obesity has quadrupled (Flegal et al., 2010).The graph above references research by Calle et al., A more recent digest of 57 studies of 900,000 adults found that the moderately obese (with BMIs of 30 to 35) lived two to four years less than those not overweight; the severely obese were akin to smokers—they lived eight to ten years less, on average (PCS, 2009).
25 Is Fat Bad?Having some body fat is normal and healthy; fat stores energy effectively for later use.Body fat has been seen as a sign of affluence, and thus has been considered attractive.Standards vary in different cultures, sometimes creating an unhealthy norm of being overweight or underweight.Being mildly overweight is not considered a problem if the person is in good physical condition or exercising.The social effects of obesity were clear in a study that followed 370 obese 16- to 24-year-old women (Gortmaker et al., 1993). When restudied seven years later, two-thirds of the women were still obese. They also were making less money—$7000 a year less—than an equally intelligent comparison group of some 5000 nonobese women. And they were less likely to be married. When appearing overweight, the same person—using the same lines, intonations, and gestures—was rated less worthy of hiring (Figure 32.10). The weight bias was especially strong against women.Obese 6- to 9-year-olds are 60 percent more likely to suffer bullying (Lumeng et al., 2010).9 in 10 individuals who had undergone bypass surgery and lost an average of 100 pounds said they would rather have a leg amputated than be obese again (Rand & Macgregor, 1990, 1991).
27 Obesity and Weight Control Physiology of ObesityOnce a person is obese, losing weight is not so easy as “just eating less.”Fat has a lower metabolic rate then other tissue, so a person might gain weight when eating “normally.”Eating less to lose weight slows metabolism. This prevents weight loss, and ensures weight gain when returning to a normal diet.Even if weight loss succeeds, a formerly obese person will have to eat less than an average person just to prevent weight gain.How does obesity develop,and why is it hard to change?It was adaptive for our ancestors to crave energy-rich food when available.Problem: energy-rich ‘junk’ food is now easily available, and cheaper than healthy foodIt is adaptive to slow down our burning of fat when food is scarce.Problem: in crash diets, our body can slow down weight lossobese patients whose daily food intake was reduced from 3500 to 450 calories lost only 6 percent of their weight—partly because their bodies reacted as though they were being starved, and their metabolic rates dropped about 15 percent (Bray, 1969). That is why reducing your food intake by 3500 calories may not reduce your weight by 1 pound.
28 Lifestyle Factors and Obesity Social Psychology of ObesityDiscrimination based on weight has been found to be stronger than race and gender discrimination.In one study, actors were seen as less employable when made to look heavier.Even children are prejudiced against the overweight.Perhaps as a result, people who are obese are more likely to be depressed or isolated.Genetics and ObesityAdopted siblings eating the same meals end up with a BMI/weight resembling biological parents, not people in the same household.Identical twins have similar weights, even when raised apart with different food.There seem to be many genes with effects on weight.Lifestyle Factors and ObesityPeople who are restless and fidgeting burn off more calories and gain less weight than others.Inadequate sleep causes weight gain, despite increased active time, because of appetite hormones.Having an obese friend correlates with becoming obese.Sedentary lifestyles and fast food may be leading to increased body fat worldwide.With sleep deprivation, the levels of leptin (which reports body fat to the brain) fall, and ghrelin (the appetite-stimulating stomach hormone) rise.By 2020, three of four Americans will be overweight or obese.
29 Losing Weight: The Challenge Losing Weight: The Plan Because of the physiological factors and perhaps due to lifestyle and peer issues:once obese, weight loss is difficult, and permanent weight loss is even harder.obsessive weight loss attempts can add to shame, anxiety, depression, and disordered eating habits.Begin with an understanding of the metabolic challenges you face, so that you blame slow progress on physiology, not poor willpower.Begin with self-acceptance and a decision to change, rather than feeling shame.Make gradual and consistent, not drastic and varying, lifestyle changes.Increase exercise and healthy food choices.Get support.Losing Weight: The PlanClick to reveal bullets and text box.If you decide to move your body’s set point to a lower body weight: