8.8 CHAPTER REVIEW

KEY POINTS

• Motivation refers to the forces that act on or within an organism to initiate and direct behavior. Three characteristics associated with motivation are activation, persistence, and intensity. Motivation is closely tied to emotion—we may be motivated to achieve certain emotions, and emotions may motivate us to take action.

• During the twentieth century, many psychologists tried to develop general theories of motivation, but each model was too limited to explain all motivated behavior.

• Instinct theories of motivation, inspired by evolutionary theory, were limited in that they described and labeled behaviors but did not explain them.

• According to drive theories, behavior is motivated by the need to maintain homeostasis. Drive theories could not account for psychological motives or motives that are not related to a drive, or unmet need.

• According to incentive theories, behavior is motivated by external rewards.

• Arousal theory is based on the notion that people are motivated o maintain an optimal level of arousal, which can vary from one person to another. People who are high in sensation seeking seek high levels of arousal.

• Humanistic theories of motivation were based on the idea that people are motivated to achieve their highest potential.

• Hunger is a biological motive, but eating behavior is also influenced by psychological, social, and cultural factors.

• Food provides glucose, the main source of the body’s energy, which is regulated by insulin. Excess glucose is stored in adipose tissue. The basal metabolic rate (BMR) is the rate at which your body uses energy for vital body functions. Energy homeostasis helps people maintain their baseline body weight, which tends to remain stable over time unless calorie intake consistently exceeds or falls short of energy expenditure.

• Physiological factors that are correlated with eating are changes in glucose, insulin, ghrelin, body temperature, and metabolism. Psychological factors that trigger eating behavior include classically conditioned stimuli and foods that, through operant conditioning and reinforcement, have acquired a positive incentive value. Satiation signals include cholecystokinin (CCK) and other physiological signals, as well as sensory-specific satiety.

• Chemical signals that regulate body weight and help maintain a stable body weight over time include leptin, insulin, neuropeptide Y, and ghrelin. These factors are part of a complex feedback loop that also involves the hypothalamus in the brain that influence appetite and metabolism so that body weight remains largely stable over time, as described by set-point theory.

• The number of overweight people in the United States and other developed countries has steadily increased in the past decades. Body mass index (BMI) is one way to calculate weight status. Someone who is obese has a high BMI and an abnormally high proportion of body fat. Factors involved in becoming overweight include inadequate sleep, the ready availability of foods with a positive incentive value, overeating, the cafeteria diet effect, individual differences in BMR, and sedentary lifestyles.

• Obesity leads to many health problems, some of which are life threatening. Several factors contribute to obesity, including genetic susceptibility, leptin resistance, and frequent dieting, which may lead to weight cycling. Obese people tend to have fewer dopamine receptors in their brains than normal-weight individuals, which may lead to compulsive eating to stimulate brain reward centers.

• According to Abraham Maslow’s hierarchy of needs, people must fulfill basic physiological needs before they can be motivated by higher psychological needs, such as self-actualization. Maslow’s model has been very influential, but it lacks empirical support.

• Self-determination theory (SDT), developed by Edward Deci and Richard Ryan, is based on the premise that people are motivated to achieve a unified sense of self and integration with others. SDT includes three innate, universal psychological needs: autonomy, competence, and relatedness. Intrinsic motivation and extrinsic motivation are important principles in SDT.

• Competence motivation refers to striving to be capable and exercise control, while achievement motivation refers to striving to excel or outperform others. The Thematic Apperception Test (TAT) is one way to measure achievement motivation. Achievement motivation is expressed differently in individualisticand collectivistic cultures.

• An emotion has three basic components: a subjective experience, a physiological response, and a behavioral or expressive response.

• Emotions have many functions, including triggering motivated behavior, and contribute to rational decision making and purposeful behavior. Emotional intelligence is needed to succeed in life. According to evolutionary psychologists, emotions are the product of evolution and help us solve important adaptive problems.

• The basic emotions are innate and the product of evolution. Women tend to be more emotionally expressive than men. Emotions can be classified in terms of their degree of activation and pleasantness, and, in collectivistic societies, their level of interpersonal engagement.

• Some emotions, such as fear, anger, and happiness, involve arousal of the sympathetic nervous system. The amygdala is a key structure in the brain’s fear circuit, which also involves the thalamus, the cortex, and the hypothalamus. The amygdala can be activated by threatening stimuli before we are consciously aware of the stimulus, an ability that has adaptive survival value.

• Facial expressions of the basic emotions are biologically innate, culturally universal, and the result of evolution. However, emotional expression is controlled by cultural display rules. Display rules also vary by gender, with men more likely to mask their emotions than women.

• Emotion theories differ in terms of which emotion component is emphasized. The James-Lange theory holds that emotion results from our perception of biological and behavioral responses. Contemporary evidence supporting the James-Lange theory includes neuroscience research demonstrating that we “feel” emotions in our body and the facial feedback hypothesis.

• There are two main cognitive theories of emotion. The two-factor theory, proposed by Schachter and Singer, holds that emotion results from applying a cognitive label to feelings of arousal. The cognitive appraisal theory states that emotional responses are triggered by a cognitive evaluation. Emotion researchers today tend to agree that emotions can be triggered in multiple ways and that instinctive emotional responses may not require a conscious cognitive appraisal.

KEY TERMS

KEY PEOPLE