CHAPTER 11

WHAT DRIVES US: HUNGER, SEX, FRIENDSHIP, AND ACHIEVEMENT

Basic Motivational Concepts

11-1 How do psychologists define motivation? From what perspectives do they view motivated behavior?

Motivation is a need or desire that energizes and directs behavior. The instinct/evolutionary perspective explores genetic influences on complex behaviors. Drive-reduction theory explores how physiological needs create aroused tension states (drives) that direct us to satisfy those needs. Environmental incentives can intensify drives. Drive-reduction’s goal is homeostasis, maintaining a steady internal state. Arousal theory proposes that some behaviors (such as those driven by curiosity) do not reduce physiological needs but rather are prompted by a search for an optimum level of arousal. The Yerkes-Dodson law states that performance increases with arousal, but only to a certain point, after which it decreases. Performance peaks at lower levels of arousal for difficult tasks, and at higher levels for easy or well-learned tasks. Abraham Maslow’s hierarchy of needs proposes a pyramid of human needs, from basic needs such as hunger and thirst up to higher-level needs such as self-actualization and self-transcendence.

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Hunger

11-2 What physiological factors produce hunger?

Hunger pangs correspond to stomach contractions, but hunger also has other causes. Neural areas in the brain, some within the hypothalamus, monitor blood chemistry (including level of glucose) and incoming information about the body’s state. Appetite hormones include ghrelin (secreted by an empty stomach); insulin (controls blood glucose); leptin (secreted by fat cells); orexin (secreted by the hypothalamus); and PYY (secreted by the digestive tract). Basal metabolic rate is the body’s resting rate of energy expenditure. The body may have a set point (a biologically fixed tendency to maintain an optimum weight) or a looser settling point (also influenced by the environment).

11-3 What cultural and situational factors influence hunger?

Hunger also reflects our memory of when we last ate and our expectation of when we should eat again. Humans as a species prefer certain tastes (such as sweet and salty), but our individual preferences are also influenced by conditioning, culture, and situation. Some taste preferences, such as the avoidance of new foods, or of foods that have made us ill, have survival value.

11-4 What factors predispose some people to become and remain obese?

Genes and environment interact to produce obesity. Obesity correlates with depression, especially among women. Twin and adoption studies indicate that body weight is also genetically influenced. Environmental influences include lack of exercise, an abundance of high-calorie food, and social influence.

Those wishing to lose weight are advised to make a lifelong change in habits: Get enough sleep; boost energy expenditure through exercise; limit variety and minimize exposure to tempting food cues; eat healthy foods and reduce portion sizes; space meals throughout the day; beware of the binge; monitor eating during social events; forgive the occasional lapse; and connect to a support group.

Sexual Motivation

11-5 How do hormones influence human sexual motivation?

For all but the tiny fraction of us considered asexual, dating and mating become a high priority from puberty on. The female estrogen and male testosterone hormones influence human sexual behavior less directly than they influence sexual behavior in other species. Women’s sexuality is more responsive to testosterone level than to estrogen level. Short-term shifts in testosterone level are normal in men, partly in response to stimulation.

11-6 What is the human sexual response cycle, and how do sexual dysfunctions and paraphilias differ?

William Masters and Virginia Johnson described four stages in the human sexual response cycle: excitement, plateau, orgasm (which seems to involve similar feelings and brain activity in males and females), and resolution. During the resolution phase, males experience a refractory period in which renewed arousal and orgasm are impossible.

Sexual dysfunctions are problems that consistently impair sexual arousal or functioning. They include erectile disorder and female orgasmic disorder, and can often be successfully treated by behaviorally oriented therapy or drug therapy. Paraphilias are conditions, which may be classified as disorders, in which sexual arousal is related to nonhuman objects, the suffering of self or others, and/or nonconsenting persons.

11-7 How can sexually transmitted infections be prevented?

Safe-sex practices help prevent sexually transmitted infections (STIs). Condoms are especially effective in preventing transmission of HIV, the virus that causes AIDS. A vaccination administered before sexual contact can prevent most human papilloma virus infections.

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11-8 How do external and imagined stimuli contribute to sexual arousal?

External stimuli can trigger sexual arousal in both men and women. In experiments, depictions of sexual coercion have increased acceptance of rape. Men respond more specifically to sexual depictions involving their preferred sex. Sexually explicit material may lead people to perceive their partners as comparatively less appealing and to devalue their relationships. Imagined stimuli (dreams and fantasies) also influence sexual arousal.

11-9 What factors influence teenagers’ sexual behaviors and use of contraceptives?

Rates of teen intercourse vary from culture to culture and era to era. Factors contributing to teen pregnancy include minimal communication about birth control with parents, partners, and peers; guilt related to sexual activity; alcohol use; and mass media norms of unprotected and impulsive sexuality. High intelligence, religious engagement, father presence, and participation in service learning programs have been predictors of teen sexual restraint.

11-10 What has research taught us about sexual orientation?

Sexual orientation is an enduring sexual attraction toward members of one’s own sex (homosexual orientation), the other sex (heterosexual orientation), or both sexes (bisexual orientation). About 3 or 4 percent of men and 2 percent of women in Europe and the United States identify as exclusively homosexual, and 3.4 percent of Americans describe themselves as lesbian, gay, bisexual, or transgender. There is no evidence that environmental influences determine sexual orientation. Evidence for biological influences includes the presence of same-sex attraction in many animal species; straight-gay brain differences; higher rates in certain families and in identical twins; exposure to certain hormones during critical periods of prenatal development; and the fraternal birth-order effect.

11-11 Is scientific research on sexual motivation value free?

Scientific research on sexual motivation does not attempt to define the personal meaning of sex in our lives, but sex research and education are not value free.

Affiliation and Achievement

11-12 What evidence points to our human affiliation need—our need to belong?

Our need to affiliate or belong—to feel connected and identified with others—had survival value for our ancestors, which may explain why humans in every society live in groups. Because of their need to belong, people suffer when socially excluded, and they may engage in self-defeating behaviors (performing below their ability) or in antisocial behaviors. Feeling loved activates brain regions associated with reward and safety systems. Ostracism is the deliberate exclusion of individuals or groups. Social isolation can put us at risk mentally and physically.

11-13 How does social networking influence us?

We connect with others through social networking, strengthening our relationships with those we already know. When networking, people tend toward increased self-disclosure. People with high narcissism are especially active on social networking sites. Working out strategies for self-control and disciplined usage can help people maintain a healthy balance between social connections and school and work performance.

11-14 What is achievement motivation?

Achievement motivation is a desire for significant accomplishment, for mastery of skills or ideas, for control, and for attaining a high standard. Achievements are more closely related to grit (passionate dedication to a long-term goal) than to raw ability.

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