1. society
2. sex

Psychology, 8th Edition – Myers
Chapter 12 – Motivation and Work
Aron Ralston’s story - cut off his own arm while stuck in a canyon.
Motivation – a need or desire that energizes and directs behavior
Perspectives on Motivation
Instinct and Evolutionary Psychology
 Instinct – a complex behavior that is rigidly patterned throughout a species and is unlearned.
 Instinct theorists
o Influenced by Darwin’s theory of natural selection
o Tried to explain human behaviors as being compelled by “instincts”  naming behaviors, not
explaining
 Evolutionary theorists
o Genes predispose species-typical behavior
Drive Reduction Theory
 Drive-reduction theory – idea that physiological need creates an aroused tension state (a drive) that
motivates an organism to satisfy the need.
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When a physiological need increases, so does a psychological drive to satisfy the need  homeostasis –
the tendency to maintain a balanced or constant internal state by the regulation of any aspect of body
chemistry
Pushed by needs and pulled by incentives – positive or negative environmental stimulus that motivates
behavior
For each motive we can ask, “How is it pushed by inborn physiological needs and pulled by incentives
in the environment?”
Arousal Theory
 Not all behaviors serve to reduce immediate physiological needs or tension states
 Arousal theory – too little or too much stimulation can motivate people to find an optimum state of
arousal
o Ex: curiosity-driven behaviors
Maslow’s Hierarchy of Needs
 Abraham Maslow’s hierarchy of needs – pyramid of human needs, beginning at the base with
physiological needs that must first be satisfied before higher-level safety needs and then psychological
needs become active.
 The order of needs is not universally set – cultural, societal, political, and financial aspects can change
the order, however the hierarchy provides a basic framework for thinking about motivation.
Hunger
 “Hunger is the most urgent form of poverty.” – Alliance to End Hunger, 2002
 Ancel Keys (1950) – 36 male volunteers, fed half of the required food to maintain weight for 6 months
 conservation of energy, rapid weight loss to 25% below starting weight, obsession with food.
The Physiology of Hunger
 Cannon and Washburn (1912), swallowed a balloon to measure stomach contractions, found that the
stomach contracts when the body feels hunger
 Hunger can persist even without a stomach (rats w/o stomach, humans w/o stomach due to cancer)  if
hunger can persist without stomach, what else triggers hunger?
Body Chemistry and the Brain
 Your body naturally monitors your calorie intake to fix deficits and maintain a stable weight, but how?
 Glucose – blood sugar that provides the major source of energy to body tissues; when low, we feel
hunger.
o Increases in insulin (hormone secreted by the pancreas, monitors blood glucose) lower blood
glucose  hunger.
 Glucose levels monitored by the brain through signals sent from the stomach, liver, or intestines
(depending on whether glucose is being deposited or withdrawn)
 Hypothalamus largely controls and monitors hunger.
o Lateral hypothalamus – brings hunger by producing the hormone orexin when glucose levels
drop
 Stimulation – eating even if well-fed
 Destroyed – no eating even facing starvation
o Lower mid-hypothalamus (ventromedial) – depresses hunger
 Stimulation – stop eating
 Destroyed – stomach and intestines process food more rapidly  obesity
 Patients with tumors near the base of the brain (hypothalamus) eat excessively and
become very overweight
 Ghrelin – hunger producing hormone secreted by an empty stomach
 Leptin – hormone secreted by fat cells, causes brain to increase metabolism and decrease hunger
 PPY – hormone secreted by the intestines that suppresses appetite
 Set point – the point at which an individual’s “weight thermostat” is supposedly set; predisposed by
heredity
o Set points can change over time with gradual rate fluctuations casting doubt on the idea that our
bodies have a preset tendency to maintain an optimum weight
 Basal metabolic rate – the body’s resting rate of energy exposure
o Less food intake – lower basal metabolic rate to conserve energy (demonstrated by a 29% drop
in basal metabolic rate in the participates in Keys’ study)
o More food intake – increased basal metabolic rate to expend excess energy (fidgeting, etc)
Psychology of Hunger
 Paul Rozin and colleagues (1998) tested 2 people with extreme amnesia (could not remember past
minute)  presented with first lunch and ate it, 20 minutes later they ate a second lunch when presented,
and another 20 minutes later they ate a third lunch when presented  part of knowing when to eat is out
memory of our last meal and the anticipation of our next meal.
Taste Preference – Biology or Culture?
 Preference for sweet and salty tastes are genetic and universal.
 Other taste preferences are conditioned or products of cultural traditions.
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People naturally avoid unfamiliar foods  evolutionary to protect against potentially toxic substances.
Preferences are also adaptive  pregnant women become most nauseous (food aversion) in the 10th
week of pregnancy when the embryo is most vulnerable to toxins; spices used in the recipes of cultures
living in hot climates inhibit the growth of bacteria
Eating Disorders
 Eating disorders provide an example of when psychological factors take precedence over physiological
needs and homeostatic pressures.
 Anorexia nervosa – an eating disorder in which a normal-weight person (usually an adolescent female)
diets and becomes significantly (15% or more) underweight, yet, still feeling fat, continues to starve.
 Bulimia nervosa – an eating disorder characterized by episodes of overeating, usually of high-calorie
foods, followed by vomiting, laxative use, fasting, or excessive exercise.
o Unlike anorexia, bulimia is marked by fluctuations in weight within or above normal ranges,
making the condition easy to hide.
 Possible causes for eating disorders
o Nurture
 Possible childhood sexual abuse
 Familial traditions of weight emphasis, competition, and achievement
 Unrealistic idea of ideal gender identities
 Cultural expectations across time (western cultures are weight-conscious)  poor body
images
 Media – fashion, ads, toys, supermodels, celebrities
o Nature
 Genetics – identical twins are more likely than fraternal twins or siblings to share an
eating disorder
Biological
 Hypothalamic centers
 Appetite hormones
 Stomach pangs
 Set point for weight
 Universal attraction to
sweet and salty
 Adaptive weariness toward
new foods
Eating Behaviors
Psychological
 Sight and smell of food
 Variety of foods available
 Memory of last meal
 Anticipation of next meal
 Mood
Socio-cultural
 Culturally learned taste
preferences
 Learned restraint in cultures
idealizing thinness
Sexual Motivation
 Alfred Kinsey (1948, 1953) – surveyed Americans (well-educated white urbanites) on their sexual
preferences and activities
o Most men and women reported having premarital sex
o Most women and virtually all men reported having masturbated
o Women who reported masturbating to orgasm before marriage seldom had difficulties
experiencing orgasm after marriage
o Enormously varied sexual behaviors
The Physiology of Sex
The Sexual Response Cycle
 Sexual response cycle – the four stages of sexual responding described by Masters and Johnson –
excitement, plateau, orgasm, and resolution
o Similar in males and females
o Excitement – genital areas become engorged with blood
o Plateau – peak of excitement, orgasm feels imminent
o Orgasm – further increases in breathing, pulse, and blood pressure; ejaculation in males; intense
pleasure for both males and females
o Resolution – return to less aroused state, quickly if orgasm occurred
 Refractory period – a resting period after orgasm, during which a man cannot achieve
another orgasm. (few minutes to a day)
 Women have a much shorter refractory period as they can be re-stimulated during
or soon after resolution
 Sexual disorder – a problem that consistently impairs sexual arousal or functioning
o Lack of sexual motivation, energy, or reusability
o Premature ejaculation or erectile dysfunction for men
o Orgasmic disorder for women
 Can be treated with behavioral therapy or medication
Hormones and Sexual Behavior
 Sex hormones have 2 effects:
o Direct physical development of male and female sex characteristics
o Activation of sexual behavior
 Estrogen – sex hormone secreted in greater amounts by females
o Peaks during ovulation
 Testosterone – most important of the male sex hormones
o Both males and female have it, greater in males
o Manufactured in the testes of males, after castration males lose much of their sexual interest in
females
 Hormone replacement therapy and testosterone injections can help maintain sexual motivation during
menopause in women and after removal of testes in men
The Psychology of Sex
 Hunger is the result of a physiological need, while sexual motivation is the result of a desire; however,
both depend on internal physiological factors, external and imagined stimuli, and cultural expectations.
External Stimuli
 Men and women (especially less-inhibited women) respond similarly to seeing, hearing, or reading
similar erotic material, however, different parts of the brain seem to be activated.
 Repeated exposure to sexual material can cause…
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Habituation (lessening) of emotional responses
Violence against women or the idea that women enjoy rape (if material is sexually violent)
Devaluation of and unhappiness with partner or relationship
Finding average women and men less attractive
Unrealistic expectations of sexual activities
Imagined Stimuli
 Fantasies and dreams can also increase sexual arousal
o People with spinal injuries and no genital sensation can feel sexual desire
 Men (gay or straight) fantasize about sex more than women.
Adolescent Sexuality
 Puberty signals the beginning of sexual motivation.
 Sexual activity in adolescents varies through time and cultures.
 Increase of sexual activity in teens in Western countries led to an increase in teen pregnancy in the 20th
century.
Teen Pregnancy
 Compared to European adolescents, Americans have lower rates of intercourse, but also lower rates of
contraceptive use  increased teen pregnancy and abortion.
o 1/3 of sexually active male teens use condoms consistently.
 Why lack of contraception use?
o Ignorance – mistaken ideas about which birth control methods will prevent pregnancy and
transfer of STIs (sexually transmitted infections); teens overestimate their peers’ sexual activity
which can influence behavior
o Guilt related to sexual activity – 72% of American girls aged 12-17 report regretting having sex;
not wanting to appear sexually promiscuous, teens may hesitate to carry and produce a condom
o Minimal communication about birth control – teens are uncomfortable discussing contraception
with their parents, partners, or peers; teens in committed relationships with supported and
engaged parents are more likely to use contraception.
o Alcohol use – correlation between sexually active teens and teens who consume alcohol;
drinking alcohol before sexual activity lowers inhibitions and decreases condom use; alcohol’s
power to lower inhibition and increase aggression can lead to sexual violence or coerced sexual
activity
o Mass media norms of unprotected promiscuity – sexual activity pervades popular TV shows and
movies, many presenting uncommitted relations with little talk of contraceptive use  sex
disinformation
Sexually Transmitted Infections
 2/3 of new infections appear in people under 25
 Condoms offer no protection against some skin-to-skin infections such as human papilloma virus (HPV)
which can lead to most genital cancers
 Condoms DO reduce the risk of contracting human immunodeficiency virus (HIV) which can lead to
AIDS
 Greater emphasis on teen abstinence within some sex education programs
 Several predictors of restraint:
o High intelligence – teens with above average intelligence test scores more often delay sex
possibly because they understand the possible negative consequences and are more focused on
future achievements and goals
o Religiosity – actively religious teens and adults more often reserve sexual acts for marriage
o Father presence – studies have shown that a father’s absence was linked to sexual activity and
teen pregnancy
o Participation in service learning programs – several studies show that teens who volunteer as
tutors or teachers’ aids or participate in community service have lower pregnancy rates  less
time for sex? More future-oriented? Greater sense of personal competence, control, or
responsibility?
Sexual Orientation
 Sexual orientation – an enduring sexual attraction toward members of either one’s own sex
(homosexual orientation) or the other sex (heterosexual orientation)
 Cultures vary in their attitudes on homosexuality, however all cultures in all times have been
predominantly heterosexual (evolutionary?  ensure reproduction)
Sexual Orientation Statistics
 Many varying statistics on the prevalence of homosexuality, however there is general consensus that 34% of men and 1-2% of women identify as homosexual (anonymous self reporting)
 Facing cultural, societal, and political backlash can cause many homosexuals to struggle with their
sexual orientation.
o Ignorance or denial of desires, hoping they will go away
o Attempted change through psychotherapy, willpower, or prayer
 Most psychologists agree that sexual orientation is neither willfully chosen or willfully changed.
 Women’s sexuality seems to be more fluid and changeable than men’s  erotic plasticity
 Gays and lesbians suffer higher rates of depression and risk of suicide, which psychologists attribute to
bullying, harassment, and discrimination
 The American Psychological Association (APA) dropped homosexuality from its list of “mental
illnesses” in 1973.
Origins of Sexual Orientation
 Psychologically caused? NO…
o Homosexuality not related to sexually abusive childhoods
o Not related to levels of hormones in the blood
o Not related to familial factors (smothering mothers, absent fathers
 Homosexuality does appear more often…
o In certain populations  musicians, poets, fiction writers, and artists
o In men with older brothers
 Bottom line  it is unclear and unproven if environmental factors influence sexual orientation, therefore
researchers have focused on studying the potential biological factors that may influence homosexuality
Same Sex Attraction in Animals
 “Gay” penguins in NY Aquarium (Wendell and Cass) and Central Park Zoo (Silo and Roy)
 Several hundred species in which occasional same-sex relations have been observed (gorillas, grizzlies,
monkeys, flamingos, owls, etc)
 Some degree of homosexuality seems to be a natural part of the animal world as well.
The Brain and Sexual Orientation
 LeVay studied cross-sections of the hypothalamus from homosexual and heterosexual males and
females (blind study)  reliably larger cell cluster in heterosexual males than in females and
homosexual males
o LeVay concluded that the cell cluster does not depict a sexual orientation center, rather sees it as
an important part of the neural pathway engaged in sexual behavior. (brain anatomy influences
sexual behavior)
 Studies have found that the anterior commissure is 1/3 larger in homosexual males than in females or
heterosexual men
 Not surprising that there are brain differences between homosexual and heterosexual people however
questions remain…
o When does the difference develop? At conception? In the womb? During childhood or
adolescence?
o Is the difference caused by experience? Or genes? Or prenatal hormones?\
Genes and Sexual Orientation
 Evidence to suggest genetic influence on sexual orientation
o Homosexuality seems to run in families
o Identical twins studies have produced interesting results  identical twins are somewhat more
likely than fraternal twins to share homosexual orientation; however in many identical twin pairs,
one twin is heterosexual while the other is homosexual
o Sexual attraction in fruit flies has been manipulated through gene experimentation
 Why would “gay genes” exist if from an evolutionary perspective, homosexuality does not lead to
natural reproduction?
o Genes can remain present in kin relationships (uncles, aunts, cousins, nieces, nephews, etc) who
share similar gene backgrounds
o Maternal genetics? “gay gene” passed down by women.
Prenatal Hormones and Sexual Orientation
 Elevated rates of homosexuality in identical and fraternal twins  not just shared genes but also shared
prenatal environment
 Proposed critical period for sexual orientation seems to be between the 2nd and 5th months after
conception  fetuses exposed to hormones typically exposed to female fetuses during this time
correlates with attraction to males later in life.
 Homosexual men seem to have fingerprint patterns more common in heterosexual females (which
develop in the womb by the 4th month)
 Homosexual men have spatial abilities similar to those of heterosexual women.
 General consensus that NATURE not nurture contributes to homosexuality.
o What consequences could this have in the future if homosexuality continues to be stigmatized?
(abortions of fetuses that have the possibility of being homosexual?)
Sex and Human Values
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Psychologists and researchers, as humans, have values and ideas about sex and sexual behaviors  can
the study of sexuality be value-free?
o Labels can describe but also evaluate (ex: deviant sexual behavior depends on our attitudes
towards sexuality)
Researchers should acknowledge that values exist and persist and be careful not to allow these to
influence the scientific study of sexuality.
The Need to Belong
 Humans are social animals  need connections to other people. Why?
o Evolutionary perspective  survival in groups, protection of young, cooperation
o Happiness  relationships (love) brings happiness and joy
o Increased social acceptance  feeling included/accepted correlates with higher self esteem
o Maintaining relationships  the fear of being alone motivates people to main and keep
relationships (even if they are negative or abusive)
o Pain of ostracism  avoiding social exclusion; exile, imprisonment, and solitary confinement
are forms of punishment for a reason.
o Fortifying health  people with close relationships suffer less depression, suicide, and early
death.
Motivation at Work
 Industrial/organizational (I/O) psychology – the application of psychological concepts and methods to
optimizing human behavior in workplaces
o Personnel psychology – a subfield of I/O psychology that focuses n employee recruitment,
selection, placement, training, appraisal and development
o Organizational psychology – a subfield of I/O psychology that examines organizational
influences on worker satisfaction and productivity and facilitates organizational change.