Unit 8: Motivation and Emotion A - Motivation

Four perspectives used to understand motivation: Instinct theory (evolutionary perspective) Drive-reduction theory Arousal theory Maslow’s hierarchy of needs

Instinct Theory Unlearned behaviors that organisms are genetically predisposed to exhibit drive us Does apply to species-typical behavior Major drawback: this theory describes motivation but doesn’t explain it

Drive-Reduction Theory Inner drives push and external incentives pull us towards particular behaviors Physiological needs (such as for food or water) create an arousal state that we then are motivated to correct to reach homeostasis Environmental stimuli also cause us to seek incentives (operant conditioning)

Arousal Theory Boredom may actually cause us to seek increased arousal (curiosity) Everyone has an optimum level of arousal Some individuals are motivated because they have a high need for arousal, others have a lower need for arousal May be affected by brain areas

Maslow’s Hierarchy of Needs He argued that the needs build on one another – we are more likely to be preoccupied with satisfying lower level needs before we move to satisfy higher levels But, the order of the needs is not universal

Common human behaviors research seeks to explain with motivational theories: Hunger – obesity, eating disorders Sexual motivation Need for belongingness – need for affiliation

Hunger Physiology of Hunger -Stomach signals hunger with contractions (pangs) -Empty stomach secretes ghrelin – but even those with no stomach still feel hungry -Low blood glucose makes us feel hungry because it causes the lateral hypothalamus to produce orexin -Ventromedial hypothalamus, PYY, and leptin depress hunger -Set point may actually be a settling point because BMR can change through calorie deprivation, exercise Psychology of Hunger -Carbs raise serotonin levels, which calms us -Genetics – preference for sweet and salty foods, avoidance of unfamiliar foods, taste aversions easily conditioned -Environmental influence evidenced by social facilitation and unit bias

Eating Disorders Types Anorexia nervosa – below normal body weight (may also purge) Bulimia nervosa – binge and purge Binge-eating – binge but no purge Causes -Related to low self- esteem, perfectionism, excessive concern with other perception of them -May have a genetic component -Culture – body image ideal, media -More common among young females, but affects males and older women too

Obesity Major health issue in United States – 2/3 overweight and 1/3 obese Increased risk of diabetes, high blood pressure, heart disease, gallstones, arthritis, some cancers, Alzheimer’s and brain tissue loss (women) Shortens life span Social effects – weight bias (discrimination), especially against women Psychological effects – associated with lower psychological well-being and 25% increase in depression and anxiety

Causes of Obesity Fat cells –We are born with a certain number of fat cells, how many may be genetic –We will never decrease the number of fat cells but we can increase them with childhood or adulthood overeating patterns Set point and BMR (metabolism) –Fat requires fewer calories to maintain than lean tissue –If we cut calories, the body will adapt by burning fewer calories, slowing metabolism Genetics –Many genes implicated –Correlation with natural parents weight not adoptive –Identical twins reared apart have similar weights Food and Activity levels –Lack of sleep related to obesity –More likely to become obese if a friend is obese –Food consumption levels changing – unit bias –Activity levels falling - technology

Losing Weight Most who lose weight will regain it Must set realistic and moderate goals Must modify lifestyle in terms of eating habits and activity levels Obesity probably not caused by guilt, hostility, oral fixation, lack of willpower, etc.

Sexual Motivation Masters and Johnson identified the sexual response cycle –Excitement, plateau, orgasm, resolution –Refractory period shorter for women than for men Sex hormones (estrogen and testosterone) play a role in development of primary and secondary sex characteristics and in sexual behavior Females - fluctuation of estrogen levels has some impact on sexual behavior, but not to the same degree as in animals - human female sexual behavior more influenced by testosterone Males - testosterone levels have little effect on sex drive unless there are large changes

Psychology of Sex Sexual behavior is influenced by both external stimuli and internal (imagined) stimuli Exposure to sexually explicit media impacts both men and women - may cause devaluation or dissatisfaction with current partner Sexual fantasies are normal

Adolescent Sexuality Major issue due to conflicting feelings - natural feelings of changes in body due to hormones may conflict with social, family, personal, religious values about sexual behavior Higher teen pregnancy rates in U.S. compared to Europe - ignorance, little communication about birth control, guilt, alcohol use, mass media norms of promiscuity STIs (STDs) - 40% of sexually active teens had an STI in 1994 Predictors of abstinence - high IQ, religious, father in the home, participation in community service

Sexual Orientation Statistics? –3 to 4% of men are homosexual –1 to 2% of women are homosexual –Less than 1% are bisexual Sexual orientation is not an indicator of mental health

Origins of homosexuality Nature -fraternal birth-order effect -Same-sex relations in hundreds of species -Brain differences -Gay men and straight women have hemispheres of about same size -Lesbian women and straight men have larger right hemispheres -Genetics seems to play a role -Prenatal hormone exposure between 2nd and 5th month -“exotic is erotic”

The Need to Belong (Need for Affiliation) Why do we become strongly attached in enduring relationships? –From an evolutionary perspective, social bonds have helped humans survive and reproduce –Being in healthy close relationships is correlated with higher levels of happiness, better health, and lower risk for psychological problem and early death

Fear of being alone is a motivating force causing us to seek acceptance Severe social isolation causes problems in children Ostracism, social exclusion, causes increased activity in anterior cingulate cortex (this area is also activated by physical pain) –May result in depressed mood, withdrawal –May then seek new friends or turn nasty