Chapter 11 Motivation

1. Chapter 11Motivation

2. Motivation • Motivation • Psychologists have made strides in understanding complicated motivated behaviors. • But many human motivations are still puzzling or seem illogical when scrutinized. • We will begin with some general principles of motivation, and then examine three areas of interest: hunger, the sex drive, and achievement.

3. Module 11.1 • General Principles of Motivation

4. Properties of Motivated Behavior • Characteristics of motivated behavior: • They are goal directed behaviors – motivated individuals keep working until they reach their goal. • They vary from time to time and one individual to the next. • If an individual varies the behavior and persists until reaching a goal, it is a motivated behavior.

5. Views of Motivation • It is hard to develop a satisfactory definition of motivation • There are several frameworks that are used in psychology to understand what motivation is.

6. Views of Motivation • Motivation as an energy • The word motivation is derived from the same root as “motion” – something that moves an organism. • Lorenz and others proposed that animals behave in instinctive ways when certain energies reach a critical level. • It is as if a specific kind of energy builds up and needs to be released, if it is not released through the preferred outlet, it will “spill” through a less preferred one.

7. Figure 11.1 According to Konrad Lorenz, energy (represented as a fluid) builds up I “reservoir” in the brain and needs to be discharged. For example, you might build up a sexual-behavior–specific energy. If that energy cannot discharge through its normal outlets (because they are blocked), the energy builds up until it discharges through some less normal outlet. (After Lorenz, 1950)

8. Figure 11.1 According to Konrad Lorenz, energy (represented as a fluid) builds up I “reservoir” in the brain and needs to be discharged. For example, you might build up a sexual-behavior–specific energy. If that energy cannot discharge through its normal outlets (because they are blocked), the energy builds up until it discharges through some less normal outlet. (After Lorenz, 1950)

9. Views of Motivation • Motivation as an energy • This view is based upon an obsolete conception of how the nervous system works. • We now understand that individuals can inhibit impulses towards a disadvantageous behavior; there is no “spilling” of unreleased energy.

10. Views of Motivation • Drive theories • A drive is a state of unrest or irritation that energizes one behavior after another until one of them removes the irritation. • Drive-reduction theory proposes that animals strive to reduce their drives as much as possible.

11. Views of Motivation • Drive theories • By extension, drive-reduction theory would predict that once all needs have been met, the organism would become inactive. • People seek variety and activity in life, not a condition of non-stimulation. • The theory ignores the role of external stimulation. Interest in food depends not only on hunger but also on what foods are available.

12. Views of Motivation • Homeostasis • Homeostasis is the maintenance of an optimum level of biological conditions within an organism. • Conditions such as temperature, hydration, nutrition, and weight are maintained at a state of equilibrium. • Unlike drive-reduction theory, in homeostasis it is necessary for the organism to expend energy to maintain the optimum state.

13. Views of Motivation • Homeostasis • The homeostasis framework overlooks the power of new stimuli to arouse behavior. • Humans also will adjust current behavior or consumption in anticipation of future needs. A person may eat one large meal in anticipation of skipping the next one, for example.

14. Views of Motivation • Incentive theories • Incentives are external stimuli that pull us toward certain actions. • Most motivated behaviors are controlled by a combination of drives and incentives. • You eat because you are hungry and also because you are standing in front of a restaurant offering appealing sights and smells of food.

15. Views of Motivation • Intrinsic and extrinsic motivations • An intrinsic motivation is a motivation to do an act for its own sake. • An extrinsic motivation is based on the reinforcements and punishments that may follow an action. • Most motivated behaviors result from a combination of intrinsic and extrinsic motivations.

16. Views of Motivation • Intrinsic and extrinsic motivations • Sometimes providing extrinsic motivations for a behavior that are already intrinsically motivated may result in a reduction of the performance of that behavior. • This effect is known as overjustification. • Overjustification predicts that if people are given more extrinsic motivation than needed to perform a task, the intrinsic motivation declines.

17. Figure 11.2 Monkeys learned to remove the pin, hook, and hasp in that order to open this device. When they started receiving a raisin instead of opening it just for fun, their performance deteriorated.

18. Table 11.1 Four views of motivation

19. Concept Check: You enjoy taking guitar lessons. Would it increase or decrease your interest if your parents offered to pay you for practicing? According to overjustification, it would decrease your interest.

20. Types of Motivation • Primary and secondary motivation • Primary motivations are automatic, built-in processes. • Secondary motivations develop as a result of specific learning experiences. You learn to perform these behaviors because they bring you closer to satisfying primary motivations. • These motivations are analogous to the conditioned and unconditioned reinforcers that we discussed in the chapter on learning

21. Concept Check: Is your interest in getting in “A” in this class an example of a primary or secondary motivation? A secondary motivation

22. Many Types of Motivation • We understand some motivations that are directly related to survival, but still puzzle over those that seem to have nothing to do with staying alive. • Unusual behaviors are most likely driven by a combination of motivating factors, both intrinsic and extrinsic in origin.

23. Module 11.2 • Hunger Motivation

24. Motives in Food Selection • Food selection based on taste • Some taste preferences are present at birth. • Humans and mammals prefer the taste of fat. • Temporary taste cravings are reported by most people on occasion, and most are difficult to explain.

25. Motives in Food Selection • Preference for familiar foods • The human taste sense is uniform among all people, but people from different parts of the world exhibit different taste preferences. • People’s food preferences are heavily influenced by familiarity. • Cuisine is one of the most stable and defining features of any culture.

26. Motives in Food Selection • Learned association with food • Animals and people associate foods with the gastrointestinal consequences of consumption. • Humans also develop preferences by associating one food with another food that they already enjoy. • Often foods are rejected because of its origins (i.e., a cat is a standard type of pet in this country and that makes the idea of eating cat distasteful to most Americans).

27. The Physiological Mechanisms of Hunger • Hunger is a homeostatic drive that makes fuel available to the body. • One major factor in initiating hunger is a drop in glucose entering the body’s cells. • Glucose is the most abundant sugar in the blood, and is an important source of energy, especially for the brain. • Excess glucose is converted into fat and stored for later use.

28. Figure 11.3 The short-term regulation of eating depends on the levels of glucose and other nutrients in the blood; it also depends on the appearance and flavor of the food, social influences, and so forth. Varying secretions of the hormones insulin and glucagon help to keep the blood nutrient levels reasonably constant.

29. Figure 11.3 The short-term regulation of eating depends on the levels of glucose and other nutrients in the blood; it also depends on the appearance and flavor of the food, social influences, and so forth. Varying secretions of the hormones insulin and glucagon help to keep the blood nutrient levels reasonably constant.

30. The Physiological Mechanisms of Hunger • Two hormones secreted by the pancreas work in complimentary fashion to regulate hunger and nutrition: • Insulin increases the flow of glucose and other nutrients into body cells. • Insulin production usually surges at the beginning of a meal and falls off after the meal is over. • Glucagon converts stored nutrients into blood glucose. • Glucagon is released between meals when energy is needed.

31. The Physiological Mechanisms of Hunger • If insulin is consistently in short supply, as in those individual afflicted with diabetes, the body will absorb little nutrition. • If insulin is consistently present in excessive amounts, most of the nutrients that are consumed are stored as fat. • In both of these instances, appetite is increased, though low insulin levels usually lead to weight loss, and high insulin levels lead to weight gain.

32. Figure 11.4 How insulin affects glucose, appetite, and weight

33. Figure 11.5 A feedback system between eating and insulin levels maintains homeostatic control of nutrition

34. The Long-Term Regulation of Hunger • In the short run, food intake does not always match the individual’s nutritional needs • Weight tends to fluctuate in the short-term, but is very stable in the long-term. • Most individuals’ weights are very close to a set point, a level that the brain and body work to maintain. • Part of the mechanism for regulating weight in the long term is the hormone leptin, which is secreted by the fat cells themselves.

35. Figure 11.6 For most people, weight fluctuates around a set point, the way a diving board bounces up and down from a central position.

36. The Long-Term Regulation of Hunger • Leptin works in the hypothalamus to alert the brain that no more fat cells are needed. • Leptin is part of the system for triggering the changes of puberty. • Some cases of obesity are linked to a lack of leptin. Many other obese individuals have the hormone but are relatively insensitive to its effects.

37. Brain Mechanisms of Hunger and Satiety • The hypothalamus is the location of several areas critical to regulation of food intake • The lateral hypothalamus appears to be critical for starting eating. Damage to this area will cause starvation through lack of interest in food.

38. Figure 11.7 The hypothalamus, a small area on the underside of the brain, contains several subareas that contribute in various ways to eating, drinking, sexual behavior, and other motivated activities.

39. Brain Mechanisms of Hunger and Satiety • The ventromedial hypothalamus is important for regulating the rate at which food is digested. When it is damaged, people will digest food quickly, eat more, and put on weight. • The paraventricular hypothalamus regulates satiety in the short-term, and if this part is damaged, a person may literally eat until they are about to burst.

40. Concept Check: Name each of the three hormones, the body part that secretes it, and its net effect on appetite. Insulin – Pancreas – Increases appetite Glucagon – Pancreas – Decreases appetite Leptin – Fat Cells – Decreases appetite

41. Concept Check: After damage to the lateral hypothalamus, an animal’s weight reaches a lower level and then fluctuates around that amount. What has happened to the set point? It has been lowered

42. Eating Too Much or Too Little • Obesity is the excessive accumulation of body fat • Obesity is a serious health risk because it increases the individual’s risk of: • Diabetes • Coronary diseases • Some types of cancer • Sleep apnea

43. Eating Too Much or Too Little • Obesity is usually due to the individual’s taking in more calories than he or she is using. • There is no reliable connection between emotional disturbances and obesity. It neither causes obesity nor necessarily results from it, despite the acceptability of “fat prejudice” in our culture. • Emotional disturbance can cause temporary fluctuations in food intake and weight.

44. Eating Too Much or Too Little • Obesity tends to run in families. Genes play a role but they are not the only cause. • The dramatic increase in obesity in the United States over the past 50 years has been linked to lifestyle factors. • We have sophisticated technology to do most of the heavy work that was done as part of day-to-day life a century ago.

45. Eating Too Much or Too Little • We also have a diet rich in fat, salt and sugar (due to the success of “fast-food”) and a food industry that uses advertising and persuasion to encourage the over-consumption of food. • Many overweight individuals are eating more than is needed, but there are some who are eating normal-sized meals and are hampered by low energy output, or low metabolism.

46. Losing Weight • Although losing weight can seem to be extraordinarily difficult, there are a number of strategies available to the motivated individual. • A certain amount of exercise must be a part of any long-term weight loss strategy. • Surgery should only be utilized for those with life-threatening levels of obesity. • Twelve-step programs such as OA can be useful for those who are comfortable with the spiritual focus of such groups. • Private counseling can be utilized for those overweight individuals who are also struggling with psychological problems.

47. Losing Weight • What about medications? • The use of medications for weight loss remains controversial. • The variety of drugs available has increased. • Medications act by weakening hunger signals to the brain, blocking absorption of fat in the intestines, or increasing metabolism.

48. The Effect of Intentional Weight Loss on Appetite • In present-day American society it is common for everyone, and particularly women, to be unhappy with their physiques. • Americans tend to worry more about what they eat. • Americans express more interest in obtaining low-fat, low-salt, “health foods.” • A slender ideal figure is presented in the media and there is a great deal of social pressure to be very thin. • Even normal weight people are frequently dieting.

49. Figure 11.10 In a study by Fallon and Rozin (1985), women and men were asked which figure they considered most attractive and which figure they believed the opposite sex considered most attractive. Each sex misestimated the other’s preferences.

50. The Effect of Intentional Weight Loss on Appetite • Dieting can be extremely difficult. • Dieting requires a great deal of mental energy. • The stress of dieting can make the dieter more vulnerable to temptation. • Dieting can contribute to the development of eating disorders.