CONCEPT I: The Development of Motivational Concepts

Motivation can be defined as those factors that arouse, sustain, and direct behavior toward attainment of some goal.

Darwin's theory of evolution prompted man to view himself as part of the animal world. It was this tradition that led McDougall to propose in 1908 that humans possessed a variety of biologically based instincts (innate forces which direct behavior in predictable ways) that served as motivators. However, such instinct-oriented theories soon lost popularity because thousands of instincts were identified. Also, the popularity of behaviorism in the mid-twentieth century, with its emphasis on learning, for a time produced a decline of interest in instincts, but recently the importance of instincts is reemerging. For example, the new field of evolutionary psychology focuses on the genetic basis of the range of human and animal behaviors, and accounts for social interactions by applying the principles of evolution.

Freud proposed that all human instincts could be categorized as one of two instincts-the urge for individual and species survival, and the tendency toward death. These two continually conflict. Also, some instinctive drives conflict with moral standards and are consequently repressed, or pushed into the unconscious. But although repressed, these impulses can still direct behavior, and are sometimes translated into a more socially acceptable form. This process is called sublimation and is responsible for creating a civilized society.

Drive-reduction theories define a primary drive (for example, hunger) as a biological need. Secondary drives (such as curiosity), which are also called learned motives, are learned from their association with primary drives. Both primary and secondary drives motivate the organism to perform some behavior that will reduce the drive state. Clark Hull believed that drives increase the organism's activity level, thus increasing its chances of satisfying the drive.

Drive-reduction theorists, however, had trouble explaining behavior that was not aimed at reducing primary drives. Researchers found that animals were strongly motivated to explore and manipulate objects in their environments. Robert White argued that humans and other animals experience intrinsic motivation-satisfaction from acting competently.

Other psychologists noticed that sometimes animals will not initiate behavior that would reduce an active drive state. In other cases, goal-directed behavior occurs not as the result of a physiological drive, but rather as the result of the expectation of receiving a reward. These expectations are called incentives. Often, an interaction between drives and incentives underlies goal-directed responses.

Expectancy-value models of motivation take into account both the expectancy (or likelihood) of achieving a particular goal and the value placed upon it.

CONCEPT II: Eating and Weight Control

One of the most impressive characteristics of weight control is the remarkably fine balance the body maintains between food intake and energy expenditure. Generally, body weight is maintained at a relatively constant level.

Hunger and eating are probably controlled by several different systems. People feel less hungry when their stomachs are full, regardless of whether they are full of food or something else. Recent evidence, however, suggests that stomach cues are of secondary importance in regulating hunger and eating.

Taste also affects hunger and eating. An initially pleasant-tasting food becomes less pleasant as more of it is consumed. Taste, however, is also secondary in regulating hunger. Subjects control intake of food even when no taste cues are available. Satiation (fullness) signals are carried by the bloodstream to brain sites that are especially susceptible to hunger cues. For instance, cholecystokinin (CCK), glycerol, and sugar in the blood regulate our eating behavior. Also, electrical or chemical stimulation of the lateral hypothalamus can cause a satiated animal to overeat drastically. If this same region is surgically destroyed, the animal will refuse to eat. On the other hand, the ventromedial hypothalamus produces nearly opposite results: When it is stimulated, the animal will refuse to eat; when it is lesioned, the animal will overeat to the point of extreme obesity. Thus, these two regions of the hypothalamus work together to control eating behavior. Other parts of the neural system are also involved in the regulation of this highly complex process.

Anorexia nervosa is a condition in which victims, 95 percent of whom are women and most of whom are young, become obsessed with thinness and starve themselves, sometimes to death. Bulimia involves periodic gorging and, after the compulsive eating session, purging the system by vomiting or taking laxatives. Although bulimia sometimes accompanies anorexia, bulimics are usually of average or even above average weight.

Body weight does seem to have an inherited component, as demonstrated by studies of twins and of adopted children, which may operate through the person's metabolic rate or through particular sensitivity to the cues that are associated with food.

Stanley Schachter has extended his cognitive theory of emotions to an analysis of hunger. He argues that people, when eating, attend to both cognitive (external) cues and physiological (internal) cues. He has demonstrated that many aspects of overweight people's behavior are subject to external cues, but not to internal ones. This indicates that at least some overweight people are more sensitive to environmental events than normal-weight people.

Nisbett has proposed a different theory. He believes that overweight people are in a nearly continuous state of hunger. As evidence, he points out that obese people react similarly to normal-weight people who have been starved. The underlying physiological mechanism for this theory is the presence of high levels of free fatty acids in an obese person's blood, indicating to that person's hunger centers a chronic state of deficit. Nisbett also believes that biological normal weight varies from one person to another, and is related to his concept of setpoint, the level of fat in our bodies that our brains are "set" to consider as normal. If we have more fat present than the setpoint, we will automatically reduce our caloric intake. If we diet to below the setpoint, we will feel the constant need for more food. The concept of setpoint suggests that weight loss produces extreme hunger until the lost weight is gained back, thus making permanent weight loss very difficult.

A related concept suggests that when people eat less than their setpoint would indicate in order to control their weight, they become restrained eaters, who continually feel they must restrain themselves from eating as much as they would like. Once, however, restrained eaters break their diets, they are likely to gorge themselves.

Obesity is considered unattractive in our society. Consequently, many people find themselves in perpetual conflict between their bodies' energy deficit and social expectations of weight control.

Weight loss can be achieved by cutting back on caloric intake and exercising. Exercise uses energy and increases the metabolic rate, counterbalancing the fuel efficiency and its associated drop in metabolic rate brought on when the body tries to maintain the original setpoint during a diet.

People who wish to lose weight can also remove from their environments unnecessary food cues that may trigger their hunger, and they should monitor their weight so they do not gain back the weight they have worked to lose.

CONCEPT III: Sexual Behavior

Factors regulating human sexual behaviors are extremely complex, in that they are influenced by the interaction of external factors and physiological changes.

Hormones are the major influence in the sexual behavior of lower animals. Female rats are sexually responsive only when their ovaries are secreting high levels of estrogen. Female humans, in contrast, are generally sexually responsive throughout their menstrual cycles. In humans, hormones may help initiate sexual responsiveness, but environmental factors play a more significant role in sexual behavior. In men, hormones do play a role in sexual performance and interest, particularly if they are attenuated before adulthood. The role, however, is smaller in humans than in other animals.

Hormones interact with the central nervous system. In the sexual response, the hypothalamus stimulates the anterior pituitary gland to release the hormones that stimulate the secretion of sex hormones by the gonads and the adrenal glands. These sex hormones travel via the bloodstream back to the hypothalamus (especially the preoptic region), where they activate the sexual arousal mechanism.

In addition to hormones, external stimuli (such as taste, smells, and sights) are needed to expand the original arousal into a sexual response.

In the late 1950s, Masters and Johnson published a laboratory analysis of sexual behavior based on observation of the sexual behavior of 700 people. The sexual response cycle is composed of four stages for both males and females. During the excitement phase, breathing, heart rate, and muscle tension increase as arousal begins. Blood rushes to the genital organs. During the plateau stage, the penis is maximally erect and the vagina further lubricated. During the organismic phase, muscles in the pelvic region and around the anus contract rhythmically. These contractions in the male expel the semen. The resolution stage involves the return to pre-arousal physiological levels.

Masters and Johnson have also identified a number of sexual dysfunctions-persistent or recurring problems with sexual activity. For males, erectile failure is an inability to achieve or maintain erection. In cases of primary erectile failure, the man has never been able to have an erection; secondary erectile failure involves difficulty with erections in only some situations. Premature ejaculation describes a condition in which ejaculation occurs too quickly. Inhibited ejaculation occurs when the man is unable to ejaculate during sex. For females, vaginismus involves involuntary muscle spasms in the vagina, making intercourse painful or impossible. Organismic dysfunction refers to inability to experience orgasm. As for men, primary orgasmic dysfunction refers to cases in which orgasm is never experienced; secondary orgasmic dysfunction involves cases where the woman experiences orgasm sometimes, but not during sexual intercourse.

Therapy for sexual dysfunctions usually involves first sensual exercises, and then gradually more sexual activities are introduced. Many of these problems occur in normal people occasionally; they become dysfunctions only when they are persistent and upsetting.

In humans, sexual responsiveness can be increased through the use of appropriate fantasies. Although it seems reasonable to suspect that sex offenders have had more exposure to pornography, research suggests that pornography does not make man more prone to sexual arousal leading to aggression. Similarly, rape appears to be motivated by anger rather than excessive sexual arousal.

CONCEPT IV: Stimulus Seeking and Arousal

The optimal level of arousal concept is based on knowledge that sensory information activates two neural pathways-one to the thalamus, the other to the reticular formation-that eventually activate the cerebral cortex in a general way. Too much stimulation induced by the reticular formation causes a blocking of behavior; too little is associated with apathy. This research forms the basis for the optimal level theory of motivation, which specifies that for appropriate behavior to take place, the amount of cortical stimulation must be within a certain optimal range.

People subjected to sensory deprivation, in which a person's sensory input is drastically reduced, find it very unpleasant. This result is consistent with optimal level theory, but inconsistent with drive-reduction theory. Sensory overload involves the bombardment by too much stimulation, and tends to be aversive and a contributor to performance. Studies of the inappropriate behavior shown by disaster victims provide support for optimal level theory. Thus, either sensory deprivation or sensory overload reduces the effectiveness of performance.

Currently, optimal level theories do not explain why some people take great risks. Solomon and Corbit have suggested that when a strong emotional response disrupts the natural balance of a person, an opponent process is activated. An opponent process is a response opposite to the initial response-for example, fear and elation. Generally, these positive and negative responses cancel each other out, but if one response (say, the fear) is suddenly eliminated, the other takes over and causes the person to associate that response (say, elation) with the situation. Furthermore, repetitions of the opponent process strengthen it. Although this theory is supported by both observations and experimental results, it cannot explain emotions that persist over a long period of time or why some people are more attracted to risk than others.

Apparently, optimal level of arousal varies with the individual. Eysenck suggested that introverts have high internal levels of cortical arousal; therefore, they require less external stimulation to reach an optimal level than do extroverts, whose internal cortical arousal level is lower. Eysenck suggests that those individuals who are more attracted to risk are extroverts-people who need much external cortical stimulation to achieve their optimal level. Indeed, research has shown that risk taking seems to be a general characteristic that extends into many areas of such a person's life. Thus, "high-sensation seekers" tend to desire greater stimulation and challenge in all parts of their lives than "low-sensation seekers," who are content to live a calmer life.

CONCEPT V: Learned Motivation: The Case of Achievement

Achievement motivation, or need for achievement, is one of several learned motivations. It is generally measured with the TAT (Thematic Apperception Test), in which subjects project their own motives onto people in ambiguous pictures.

Persons with high need for achievement are more likely to persist longer at tasks, do better on exams, select occupations that require individual initiative, and set challenging but realistic goals. Those with low need for achievement are more likely to set goals that are either too easy or too difficult, and they also score high in fear of failure. Furthermore, people with low expectations tend to attribute their failures to lack of ability and their successes to external factors. Those with high need for achievement are more likely to attribute personal failure to insufficient effort and success to their own ability.

Also, people who attribute achievements to their own abilities often place higher values on success, and they therefore seek out challenging tasks. People who attribute success to external causes and failures to themselves tend to avoid challenges, and don't persist at difficult tasks.

Boys who scored high in achievement motivation have been shown to have mothers who expected independence in their children and who used rewards rather than punishments. Parents who encouraged obedience and who were aloof and domineering tended to have boys low in achievement. Thus, achievement motivation develops in childhood.

In McClelland's research and in the Kakinada project, adults were taught to have fantasies of their own success. The businessmen who participated in these projects became more successful, thus indicating that motivation is essential for altering behavior.

Achievement motivation predicts the behavior of men better than that of women. Matina Horner suggests that because women play two contradictory roles in our society (achievement versus femininity), they are motivated by a fear of success as well as a fear of failure. Indeed, her research has indicated women fear success more than men. Horner's results have not always been replicated. Instead of measuring fear of success, she seems to have measured the subject's assessment of the negative consequences associated with deviations from traditional sex roles (women executives and men nurses, for example). Supporting research has shown that successful women do seem to be avoided by some men in our society at present.

Another reason why women fail to persist at challenging tasks is that women make different attributions for failure than do men. Carol Dweck has found that women are more likely than men to attribute failure to lack of ability rather than lack of effort. Interpreting failure in this negative fashion is related to nonachievement. Furthermore, this tendency has been shown to be encouraged by grade school teachers in their differential treatment of boys and girls. Eccles, however, points out that achievement motivation and performance are the result of a complex interaction of multiple factors. Her research shows that girls drop out of math, not because they attribute failure to lack of ability, but because they value math less than boys do. More complete explanations will require theories more complex than those presently available.