Chapter 10: Motivation

Motivation Motives – needs, wants, desires leading to goal- directed behavior Motivational Factors: Biological Social

Figure 10.2 The diversity of human motives

Instinct Theory: We are motivated by our inborn, automated, behaviors.

Drive-Reduction Theory Biological We want to maintain homeostasis If something about us is out of balance, we create a drive or need to get us back to our regular state.

Arousal Theory Innate desire to gather information and stimulation Still seeks a bit of a balance though: –We seek adventure when we are bored –BUT we also become stressed by too much arousal

Management Theory Carrot and Stick idea. We are motivated by choosing between different option with various rewards and punishments. Often several factors will come into conflict with each other.

Approach-Approach Conflict Choosing between two different rewards:

Approach-Avoidance Conflict Both options have rewards and punishments. –e.g. Federal mandate away from incandescent bulbs makes people angry and costs money, but will lower nation’s energy consumption over time.

Avoidance-Avoidance Conflict Neither options are attractive, but for different reasons.

The Motivation of Hunger and Eating: Biological Factors Brain regulation –Ventromedial Hypothalamus stimulates fullness. –Lateral Hypothalamus stimulates hunger.

Hunger, more biological factors When you eat, your body (pancreas) secrets Insulin. Insulin turns the glucose (blood sugar) into either energy or fat. Eventually it’ll use so much glucose that your blood sugar will drop, which triggers more hunger. Also “Leptin” which is a hormone secreted by fat cells suppresses hunger.

The Motivation of Hunger and Eating: Environmental Factors Food-related cues –Appearance, odor, effort required, presence of others, amount, variety Learned preferences and habits –Exposure –When, as well as what. 3 meals a day Stress –Link between heightened arousal/negative emotion and overeating

Eating Disorders Anorexia Nervosa Bulimia Nervosa Binge-Eating Biological influence (Twins tend to share disorders) Cultural influences (Western females more likely to develop disorders)

Obesity One’s weight exceeds one’s ideal body weight by 20% Body Mass Index Evolutionary explanations Genetic predisposition –adoption & twin studies Set point – natural body weight Settling point – weight remains stable unless there is a lasting change in eating or exercise Dietary restraint can lead to overeating b/c of control issues

The Roots of Obesity Leptin’s signals that fat stores are sufficient isn’t being received –genetic basis for this? Ghrelin – hormone produced by stomach; signals anticipation of a meal –Dysfunctional signaling about whether food has been or is about to be eaten can skew brain’s energy-regulation mechanisms –One treatment for obesity (gastric bypass) alters levels of gut hormones, like ghrelin, to reduce appetite

Warm Up In the United States about 65% of heterosexual women orgasm less than half of the time they have genital intercourse. 10% never orgasm. This is lower than the world-wide average. Think silently to yourself (we’ll talk in a bit) about why this might be.

Quick History of Studying Sex Freud in the 1890s studied childhood repression and “hysteria.”

Robert Dickinson in the 1920s studied female orgasm. Did research showing that women who self-pleasured were twice as likely to orgasm during sex. Went on to invent the electric vibrator.

Masters and Johnson 1940s Studied at first the biology of sex, then the psychology. Developed both theory of the stages of arousal and the idea of a “Central Arousal System” and a “Peripheral Arousal System”

The Human Sexual Response William Masters and Virginia Johnson, 1966 Stages of sexual response cycle: Excitement – initial arousal, vascocongestion Plateau – continues to build at slower pace Orgasm – peak intensity and discharged Resolution – subsiding arousal Refractory period for men after orgasm

Figure The human sexual response cycle

Impact of Central Arousal System Your ideas of sex influence how you have sex and what you find pleasurable. e.g. Breasts in most of the world are not sexual. Also, rise of pornography, particularly violent pornography is linked with poorer male sexual performance. Why might that be?

Sexual Motivation and Behavior: Determining Desire Hormonal regulation –Estrogens (female) before ovulation, sexual interest  –Androgens (male) –Testosterone  sexual interest  Pheromones –Synchronized menstrual cycles Evolutionary factors?

Sexual Orientation Heterosexual – Bisexual – Homosexual continuum Theories explaining homosexuality Environmental – it’s learned behavior Biological - most men and women with homosexual orientations can trace their leanings back to early childhood; genetic predisposition, possibly on X chromosome; organizing effects of prenatal hormones Interactionist – genes and hormones shape temperament which ultimately shapes sexual orientation through chain of events

Figure Homosexuality and heterosexuality as endpoints on a continuum Kinsey’s 7 point scale 1948, 1953

Figure How common is homosexuality?