2Motivational Theories Instinct Theory: William JamesInstincts are inherited tendencies that are not subject to reason.Humans are motivated by a variety of instinctsIn 1890, James identified 37 different instincts, including cleanliness, curiosity, parental love, sociability, sympathy and jealously.He believed that these instincts provided the basis for human behavior.Psychologists in the early 1900’s gradually expanded James list until it contained more than 10,000 instincts.
3Most psychologists today believe that humans have very few instincts Most psychologists today believe that humans have very few instincts. They only consider something an instinct if it is innate, unlearned, and present at birth, such as the sucking reflex-a survival instinct.Facial expressions also seem to be instinctual; even newborns appear to smile.Some psychologists also characterize hunger, thirst, and keeping warm as instincts.Evolutionary psychologists believe such behaviors evolved because they promote survival of the species.Some also believe that helping, aggression, and even mate selection are instinctual and genetic. They believe we have an innate desire to create offspring so that our genes will survive in our children.
4Freud and Instinct Theory Freud believed that instincts motivate human behaviorFreud believed that humans had both survival instincts which he called “Eros” and death instincts which he called “Thanatos”.Motivation is caused by sexual and aggressive instincts.He believed that instincts resided in what he called the “id”, and that the two most primary instincts were sex and aggression.
5Today’s Views on Instincts Few psychologists today subscribe to the instinct theory.The instinct theory of motivation fell out of favor by the 1920’s.Lists identifying thousands of instincts merely labeled behavior without explaining what caused it.In addition, instinct theory completely ignored the effects of learning and culture on human behavior.
6Drive Reduction Theory Clark Hull, the chief proponent of the drive reduction theory, believed that humans have biological needs that demand satisfaction, such as the need for food, water and sleep.By the 1950’s, drive reduction theory had all but replaced instinct theory as the model for explaining motivation.Hull defined need as a “state of deprivation,” and drive as a “state of bodily tension that arises from an unmet need.”“Drive reduction” refers to satisfying drives in order to reduce this tension.
7Drive ReductionDrives cause tension. In the drive reduction theory, behavior comes from a need to eliminate this tension and restore a state of balance called “homeostasis.”Any disturbance in homeostasis (such as changes in body temperature or in oxygen or blood sugar levels) gives rise to drives, which activate behaviors that will help the body return to a state of balance.For example, if Taylor’s blood sugar level drops because she hasn’t eaten in 5 minutes, she becomes hungry. Hunger motivates her to seek food; eating a loaf of bread for breakfast restores her homeostasis.Hull believed that when someone engages in a particular behavior that satisfies a drive, the body remember this. Consequently when the drive arises again, the person will tend to respond with the same behavior. This is know as a “habit.”
8Primary vs. Secondary Drives Primary drives are innate, inborn, and physiological in nature; they include things such as hunger, thirst and sexual desire.Secondary drives are psychological rather than physiological and arise as a result of our experiences. For example, we aren’t born with the innate desire to become wealthy; instead we may acquire that desire because we learn that money allows us to more easily obtain things that satisfy our primary needs.Hull believed that secondary drives are actually behaviors that we associate with the drive reduction of primary needs. As a result of this association, these behaviors become drives themselves.
9Harry Harlow Claimed that Hull overlooked important factors. Drive reduction theory focuses on drives that satisfy “survival” needs.Harry Harlow challenged the notion that all drives ultimately satisfy basic survival needs.According to Harlow, Hull overlooked some very important factors in both animal and human motivation. For example, in drive reduction theory an infant becomes attached to its mother because the mother can satisfy the infant’s hunger and thirst. Harlow doubted this explanation for infant-mother attachment.
10Intrinsic and Extrinsic Motivation Intrinsic motivation: a desire to do something because you enjoy doing it, such as playing football, painting, hiking, listening to music, ect. You don’t expect to receive a reward as a result of these activities; you do them just because you like to.Extrinsic motivation: a desire to something in order to gain a reward or avoid a punishment. Extrinsic motivation occurs when you engage in a certain activity in order to gain a reward or avoid a punishment.For example, most adults are extrinsically motivated to go to work: they don’t particularly enjoy spending 40 ormore hour a week at the office, but doing so gets them a reward—a paycheck.Another example: if your parents have ever told you at dinner, “Eat your vegetables or you won’t get dessert,” they are providing you with an extrinsic motivation to do what they want. Your reward—dessert!
11Incentive TheoryIncentive theory suggests that people act in order to obtain rewards and avoid punishments.Rewards and punishments shape behavior.Examples of incentives: incentives could include things such as a banana split, a cash bonus, an “A” on your report card, or even approval from your peers.Drive reduction theory focuses on internal states; incentive theory stresses the role of the environment.
12The Motivation of Hunger Biological hunger factors come from physiological changes in blood chemistry and signals from digestive organs that provide feedback to the brain, which in turn, triggers us to eat or stop eating.Psychological hunger factors come from learned associations between food and other stimuli, such as snacking while watching a movie; sociocultural influences, such as pressures to be thin; and various personality problems, such as depression, dislike of body image or low self esteem.Genetic hunger factors come from inherited instructions found in our genes. These instructions determine the number of fat cells or metabolic rates of burning off the body’s fuel, which push us toward being normal, overweight, or underweight.
13Biological Hunger Factors Peripheral CuesPeripheral cues come from the changes in blood chemistry or signals from digestive organs, which secrete various hormones.Stomach: When empty it secretes a newly discovered hormone, ghrelin, which carries hunger signals to the brains hypothalamus, the master control for hunger regulation. When the stomach is full, stretch receptors in the walls send “full signals” to the brains hypothalamus, which decreases appetite.The liver: monitors the level of glucose in the blood. When the level of glucose falls, the liver sends “hunger signals” to the hypothalamus. When the level of glucose rises the liver sends “full signals” to the hypothalamus.The intestines: also secrete ghrelin, which carries “hunger signals” to the hypothalamus. The intestines also secrete a newly discovered hormone, PYY, which carries “full signals” to the hypothalamus which decreases appetite. Finally, the intestines secrete a hormone called CCK, which signals the hypothalamus to inhibit eating.
14Fat Cells: secrete a hormone called leptin, which also acts on the hypothalamus. If the levels fall the hypothalamus increases appetite; if the levels are rising, the hypothalamus decreases appetite. The secretion of leptin helps maintain a constant level of body fat and defend against starving the body to death.Pancreas: Secretes the hormone insulin which helps the body extract glucose from the blood. (Inadequate supply of insulin causes diabetes)
15Biological Hunger Factors Central Cues Central cues result from activity in different brain areas, which in turn results in increasing or decreasing appetite.The lateral hypothalamus refers to a group of brain cells that receive “hunger signals” from digestive organs- increase in ghrelin, fall in the level of blood glucose, and fall in levels of leptin. The lateral hypothalamus interprets these “hunger signals” and increases your appetite.For example: ESB of the lateral hypothalamus causes rats to start eating. While destruction of the lateral hypothalamus causes rats to stop eating and even starve without special feedings.
16Ventromedial hypothalamus refers to a group of brain cells that receive “full signals” from digestive organs-full stomach activates stretch receptors, rise in the level of blood glucose, rise in levels of leptin, and increase in hormones, PYY and CCK. The ventromedial hypothalamus interprets these “full signals” and decreases appetite.For example: ESB of the VHT causes rats to stop eating, while destruction of the VHT causes rats to overeat and become obese.Other researchers have traced eating problems to disruptions in the levels of dopamine, a neurotransmitter.Other theories about hunger have focused on neural circuits rather than on anatomical centers in the brain.
17Psychological Hunger Factors In a 1971 study, psychologist Stanley Schachter and a colleague altered the clock in a room so that it ran either fast or slow. They wanted to mislead subjects as to the time of day. When Schachter offered overweight subjects crackers, they would eat twice as many if the clock showed that it was later in the afternoon than it actually was. Subjects of normal weight ate fewer crackers when they thought it was late because they said they did not want to spoil their appetite for dinner.
18Environmental Factors in the Regulation of Hunger Palatability: The better it taste the more you will consume.
19Quantity: People tend to finish what is in front of them. Variety: People consume more food when there is a greater variety.
20Presence of others: People eat more when others are around Presence of others: People eat more when others are around. The more people at the table, the longer you are there and the more you eat.
25Genetic Hunger Factors Fat Cells: Fat cells numbers are primarily determined by heredity. Fat cells shrink if we lose weight and they enlarge if we are gaining weight. Thus if we inherit more fat cells, we have a predisposition to be fatter than the average.Set Point refers to a certain level of body fat that our bodies strives to maintain constant throughout our lives.If a person diets to reduce the level of fat stores, the body compensates to maintain fat stores by automatically lowering metabolic rate and thus consuming less fuel.Metabolic rate refers to how our bodies break food down into energy and how quickly our bodies burn off that fuel.Researchers found that exercise raises our metabolic rate 10 to 20%Nicotine raises the metabolic rate 4 to 10 %
26Obesity and Health Issues If a person is 15 to 20% over their ideal body weight, he/she is considered overweight.Health risks associated with obesity:Coronary DiseaseStrokeDiabetesArthritisBack ProblemsDigestive diseasesSome studies suggest that at least 30 percent of all Americans are overweight.Studies have found that at any given time, between 25 and 50 percent of all women are on a diet.
27AnorexiaAnorexia nervosa is a psychiatric illness that describes an eating disorder, characterized by extreme low body weight and body image distortion. With an obsessive fear of gaining weight.Anorexia nervosa is a dangerous medical condition that can causesevere complications—especially for teens. To begin with, many who suffer from anorexia have cardiovascular problems such as irregular heartbeat and low blood pressure.
28They also often develop gastrointestinal problems such as chronic constipation and abdominal pain. Many young female anorexics suffer menstrual irregularities.Some, as a result of their extreme dieting behavior, render themselves incapable of gettingpregnant.Between 5 and 6 percent of all anorexics die from the disorder. Most of these deaths result either from suicide or cardiovascular episodes such as heart attacks.Karen Carpenter, a pop singer in the 1970s, died at the age of 32 from a heart attack caused by anorexia nervosa.
29Psychological Explanation A desire to avoid full maturationWanting to stay a little girl because they feel safe.
30BulimiaBullets # 1–2 Bulimia, an eating disorder related to anorexia, was first diagnosed in the 1980s. It involves a ritual known as “binging and purging.”The binging usually occurs as a response to stress, depression, or a drop in self-esteem. After gorging on as many as 20,000 calories at a time, purging begins.Bulimics try to rid themselves of all the calories from the binge by vomiting, fasting, using diuretics and laxatives, or other methods. Most of the time, bulimics treat their gorging and purging as secret, private rituals.Like anorexics, bulimics also obsess about their weight. Unlike anorexics, bulimics tend to maintain a normal weight and rarely look different from ordinary people.Bulimia often begins in late adolescence. Sufferers may alternate between bulimic behavior and strict dieting.
31Bullet # 4 Bulimia can cause serious medical complications Bullet # 4 Bulimia can cause serious medical complications. Constant vomiting resulting from bulimia erodes tooth enamel and can also cause cavities. Repeated vomiting affects the salivary glands and can cause the stomach to ulcerate, or even to rupture, which results in death. Bulimia also tends to disrupt the body’s electrolyte balance. In addition, constant purging can cause an irregular heartbeat and even cardiac arrest.
32Causes Of Eating Disorders Our society often places unrealistic pressures on young women to be thin. These pressures can contribute to the development of both anorexia and bulimia.According to one study (Rubenstein, Caballero, 2000), 50 to 75 percent of adolescent females are unhappy with their weight and body image. Consequently, dieting among teen girls has become a normative pattern.The media constantly bombard teenage girls with images of ultra-thin models and actresses, creating distorted conceptions of ideal body type.