Chapter 12 – Motivation and Work
• Motivation is the need or desire that energizes behavior and directs it toward a goal.
• Perspectives on Motivation
• There are four perspectives scientists have when looking at motivation including: • Instinct theory
• Drive reduction theory
• External/Arousal theory
• Abraham Maslow’s hierarchy of needs
• Instincts and Evolutionary Psychology
• To be an instinct, a complex behavior must have a fixed pattern throughout a species and be unlearned. • Early instinct theorists tried to explain motivation through this theory but they were merely listing instead of explaining such behaviors.
• Drives and Incentives
• Drive reduction theory- the idea that a psychological need creates an aroused state that drives the organism to reduce the need of essential cares. • When the physiological need increases, so does the psychological drive. • The aim of drive reduction is homeostasis
• Homeostasis is the tendency to maintain a balanced or constant internal state; the regulation of any aspect of body chemistry. • Incentives are positive or negative environmental stimuli that motivates behavior.
• Optimal Arousal
• Not all behaviors reduce immediate physiological needs or tension states. • The curiosity of small children and baby monkeys is not motivated by any immediate physiological need. Thus giving rise to the arousal theory.
• A Hierarchy of Motives
• The hierarchy of needs is Maslow’s pyramid of human needs, beginning at the base with physiological needs that must be first be satisfied before higher level safety needs and then psychological needs become active.
• To find out what exactly triggers hunger, A.L Washburn swallowed a balloon and then inflated it in his stomach. Once inflated, the balloon would transmit his stomach contractions to a recording device. Each time he felt hungry, he would push a button. • He revealed that he was having stomach contractions when ever he was hungry. • Even when the stomach was removed from some rats, they were still eating. • Glucose is the form of sugar that circulates in the blood and provides the major source of energy for body tissues. When its level is low, we feel hungry. • By increasing insulin, glucose is then reduced because this hormone can convert glucose into stored fat. • Once your blood glucose level drops, your hunger increases. • Once there is a drop, signals from the stomach, intestines and liver start to signal your brain to motivate eating. • Hunger was found to be centered in the hypothalamus. • The lateral side brings on the stimulus for hunger. When stimulated, animals began to eat and when it was destroyed, starving animals would stop eating. • This happens by this region releasing orexin, a hormone which triggers hunger. • The ventrome dial hypothalamus region depresses hunger, when the area is stimulated, animals will stop eating and when it is destroyed, it will cause the intestines to process food more rapidly. Explained why people with tumors in this region ate excessively and would gain weight. • Ghrelin is the hunger arousing hormone secreted by an empty stomach. • Hunger dampening chemicals secreted by fat cells are known as leptin. • PYY is the digestive hormone which suppresses appetite. • One of the theories states that one may manipulate the lateral and ventromedial hypothalamus and alter the body’s center which regulates our intake depending on our predisposed body weight also known as the set point. • Basal Metabolic rate is the body’s resting rate of energy expenditure. • This may be untrue because there can be psychological factors which drive hunger. • Thus, theorists have been focusing on the settling point which is the level which a person’s weight settles in response to caloric intake and expenditure.
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