Preview Question 1: What underlying assumption is shared by instinct theory and evolutionary psychology?
Preview Question 2: How does drive-reduction theory help us understand the forces that energize and direct some of our behavior?
Preview Question 3: What type of motivated behavior does arousal theory attempt to explain?
Preview Question 4: What is the basic idea behind Maslow’s hierarchy of needs?
Preview Question 5: What physiological factors cause us to feel hungry?
Preview Question 6: What psychological influences affect our eating behavior and feelings of hunger?
Preview Question 7: What factors predispose some people to become and remain obese?
Preview Question 9: How do sex hormones influence human sexual development and arousal?
Preview Question 10: How do internal and external stimuli contribute to sexual arousal?
Preview Question 11: What factors influence teenagers’ sexual attitudes and behaviors?
Preview Question 12: What does current research tell us about why some people are attracted to members of their own sex and others are attracted to members of the other sex?
Preview Question 14: Why do some psychologists believe we have a need to belong-to affiliate with others?
Preview Question 15: What characteristics are shared by people with a high need to achieve?
Preview Question 16: Why are some of us more than others driven to excel?
Chapter 12 motivation and work
2MotivationMotivational Concepts Instincts and EvolutionaryPsychology Drives and Incentives Optimum Arousal A Hierarchy of Motives
3MotivationHunger The Physiology of Hunger The Psychology of Hunger Obesity and Weight Control
4MotivationSexual Motivation The Physiology of Sex The Psychology of Sex Adolescent Sexuality Sexual Orientation Sex and Human Values
5MotivationThe Need to BelongAchievement Motivation Identifying Achievement Motivation Sources of Achievement Motivation
6MotivationMotivation is a needor desire that energizesbehavior and directs ittowards a goal.Aron Ralston wasmotivated to cut hisarm in order to freehimself from a rockthat pinned him down.Aron RalstonAPPhoto/RockyMountainNews,JudyWalgren
7Perspectives on MotivationFour perspectives used to explain motivationinclude the following:1. Instinct Theory (replacedby the evolutionaryperspective)2. Drive-Reduction Theory3. Arousal Theory4. Hierarchy of Motives
9Drives and IncentivesWhen the instinct theory of motivation failed, itwas replaced by the drive-reduction theory. Aphysiological need creates an aroused tensionstate (a drive) that motivates an organism tosatisfy the need.
10IncentiveWhere our needs push, incentives (positive ornegative stimuli) pull us in reducing our drives.A food-deprived person who smells baking bread(incentive) feels a strong hunger drive.
11Optimum ArousalHuman motivation aims to seek optimum levelsof arousal, not to eliminate it. Young monkeysand children are known to explore theenvironment in the absence of a need-baseddrive.HarlowPrimateLaboratory,UniversityofWisconsinRandyFaris/Corbis
12A Hierarchy of MotivesAbraham Maslow (1970)suggested that certainneeds have priority overothers. Physiologicalneeds like breathing,thirst, and hunger comebefore psychologicalneeds such asachievement, self-esteem, and the need forrecognition.(1908-1970)
13Hierarchy of NeedsHurricane SurvivorsMenahemKahana/AFP/GettyImagesMarioTama/GettyImagesDavidPortnoy/GettyImagesforSternJoeSkipper/Reuters/Corbis
14HungerWhen are we hungry?When do we eat?When there is no food in our stomach.When we are hungry.How do we know when our stomach is empty?Our stomach growls. These are also calledhunger pangs.
15The Physiology of HungerStomach contractions (pangs) send signals tothe brain making us aware of our hunger.
16Stomachs RemovedTsang (1938) removed rat stomachs, connected theesophagus to the small intestines, and the rats stillfelt hungry (and ate food).
17Body Chemistry & the BrainLevels of glucose inthe blood aremonitored byreceptors (neurons) inthe stomach, liver, andintestines. They sendsignals to thehypothalamus in thebrain.Rat Hypothalamus
18Hypothalamic CentersThe lateral hypothalamus (LH) brings on hunger(stimulation). Destroy the LH, and the animal hasno interest in eating. The reduction of bloodglucose stimulates orexin in the LH, which leadsrats to eat ravenously.
19Hypothalamic CentersThe ventromedial hypothalamus (VMH)depresses hunger (stimulation). Destroy the VMH,and the animal eats excessively.RichardHoward
20Hypothalamus & HormonesThe hypothalamus monitors a number of hormones thatare related to hunger.Hormone Tissue ResponseOrexin increase Hypothalamus Increases hungerGhrelin increase Stomach Increases hungerInsulin increase Pancreas Increases hungerLeptin increase Fat cells Decreases hungerPPY increase Digestive tract Decreases hunger
21Set PointManipulating the lateral and the ventromedialhypothalamus alters the body’s “weightthermostat.” Heredity influences set point andbody type.If weight is lost, food intake increases and energyexpenditure decreases. If weight is gained, the oppositetakes place.
22The Psychology of HungerMemory plays an important role in hunger. Dueto difficulties with retention, amnesia patientseat frequently if given food (Rozin et al., 1998).
23Taste Preference: Biology or Culture?Body chemistry and environmental factorsinfluence not only when we feel hunger but whatwe feel hungry for!RichardOlsenius/BlackStarVictorEnglebert
24Hot Cultures like Hot SpicesCountries with hot climates use more bacteria-inhibiting spices in meat dishes.
25Eating DisordersAnorexia Nervosa: A condition in which anormal-weight person (usually an adolescentwoman) continuously loses weight but still feelsoverweight.ReprintedbypermissionofTheNewEnglandJournalofMedicine,207,(Oct5,1932),613-617.LisaO’Connor/Zuma/Corbis
26Eating DisordersBulimia Nervosa: A disorder characterized byepisodes of overeating, usually high-caloriefoods, followed by vomiting, using laxatives,fasting, or excessive exercise.
27Theorized Reasons for EatingDisorders1. Sexual Abuse: Childhood sexual abuse doesnot cause eating disorders.2. Family: Younger generations develop eatingdisorders when raised in families in whichweight is an excessive concern.3. Genetics: Twin studies show that eatingdisorders are more likely to occur inidentical twins rather than fraternal twins.
28Obesity and Weight ControlFat is an ideal form ofstored energy and isreadily available. Intimes of famine, anoverweight body wasa sign of affluence.
29Obesityhttp://www.cyberdiet.comA disorder characterized by being excessivelyoverweight. Obesity increases the risk for healthissues like cardiovascular diseases, diabetes,hypertension, arthritis, and back problems.
30Body Mass Index (BMI)Obesity in childrenincreases their risk ofdiabetes, high bloodpressure, heartdisease, gallstones,arthritis, and certaintypes of cancer, thusshortening their life-expectancy.
31Obesity and MortalityThe death rate is high among very overweightmen.
32Social Effects of ObesityWhen women applicants were made to lookoverweight, subjects were less willing to hirethem.
33Physiology of ObesityFat Cells: There are 30-40 billion fat cells in thebody. These cells can increase in size (2-3 timestheir normal size) and number (75 billion) in anobese individual (Sjöstrum, 1980).
34Set Point and MetabolismWhen reduced from 3,500 calories to 450 calories,weight loss was a minimal 6% and the metabolicrate a mere 15%.The obese defend their weight by conserving energy.
35The Genetic FactorIdentical twin studies reveal that body weight hasa genetic basis.The obese mouse on the left has a defective gene for the hormoneleptin. The mouse on the right sheds 40% of its weight wheninjected with leptin. CourtesyofJohnSoltis,TheRockefellerUniversity,NewYork,NY
36ActivityLack of exercise is a major contributor to obesity.Just watching TV for two hours resulted in a 23%increase of weight when other factors werecontrolled (Hu & others, 2003).
37Food ConsumptionOver the past 40 years, average weight gain hasincreased. Health professionals are pleading withUS citizens to limit their food intake.
38Losing WeightIn the US, two-thirds of the women and half ofthe men say they want to lose weight. Themajority of them lose money on diet programs.
39Plan to Lose WeightWhen you are motivated to lose weight, begin aweight-loss program, minimize your exposure totempting foods, exercise, and forgive yourself forlapses.JoeR.Liuzzo
41Sexual MotivationSexual motivation is nature’s clever way ofmaking people procreate, enabling our speciesto survive.
42Hormones and Sexual BehaviorSex hormones effect the development of sexualcharacteristics and (especially in animals)activate sexual behavior.Male TestesTestosterone(Small amounts ofestrogen)FemaleOvariesAdrenalsEstrogen(Small amounts oftestosterone)
43EstrogenFemale animals “in heat” express peak levels ofestrogen. Female receptivity may be heightenedwith estrogen injections.Sex hormones may have milder affects on humans thanon animals. Women are more likely to have sex whenclose to ovulation (increased testosterone), and menshow increased testosterone levels when socializingwith women.
44TestosteroneLevels of testosterone remain relatively constantin males, so it is difficult to manipulate andactivate sexual behavior. Castration, whichreduces testosterone levels, lowers sexualinterest.
45The Psychology of SexHunger responds to a need. If we do not eat, wedie. In that sense, sex is not a need because if wedo not have sex, we do not die.
46Adolescent SexualityWhen individuals reach adolescence, theirsexual behavior develops. However, there arecultural differences.Sexual promiscuity in modern Western culture is muchgreater than in Arab countries and other Asiancountries.
47Sexually Transmitted Infections1. High Intelligence: Teens with higher intelligenceare likely to delay sex.2. Religiosity: Religious teens and adults often reservesex for a marital commitment.3. Father Presence: A father’s absence from home cancontribute to higher teen sexual activity.4. Learning Programs: Teens who volunteer and tutorin programs dedicated to reducing teen pregnancyare less likely to engage in unsafe sex.Factors that reduce sexual activity in teens.
48Sexual OrientationSexual orientation refers to a person’s preferencefor emotional and sexual relationships withindividuals of the same sex, the other sex,and/or either sex.Homosexual Heterosexual Bisexual
49Sexual Orientation StatisticsIn Europe and America, based on many nationalsurveys, homosexuality in men is 3-4% and inwomen is 1-2%.As members of a minority, homosexuals often strugglewith their sexual orientation.
50Origins of Sexual OrientationHomosexuality is more likely based onbiological factors like differing brain centers,genetics, and parental hormone exposure ratherthan environmental factors.Homosexual parentsCynthiaJohnson/Timemagazine
51Animal HomosexualityA number of animalspecies are devoted tosame-sex partners,suggesting thathomosexuality existsin the animal world.Wendell and CassDavidHecker/AFP/GettyImages
52Genes & Sexual OrientationA number of reasons suggest thathomosexuality may be due to genetic factors.1. Family: Homosexuality seems to run in families.2. Twin studies: Homosexuality is more common inidentical twins than fraternal twins. However, thereare mixed results.3. Fruit flies: Genetic engineers can geneticallymanipulate females to act like males duringcourtship and males to act like females.
54The Need to Belong“[Man] is a social animal,” (Aristotle).Separation from others increases our need tobelong.“Cast Away,” Tom Hanks, suffersfrom social starvation.20thCenturyFox/Dreamworks/TheKobalCollection
55Aiding SurvivalSocial bonds boosted our ancestors’ survivalrates. These bonds led to the following:1. Protecting against predators, especially for the young.2. Procuring food.3. Reproducing the next offspring.
56Belongingness1. Wanting to Belong: The need to belong colors ourthinking and emotions.2. Social Acceptance: A sense of belonging withothers increases our self-esteem. Social segregationdecreases it.3. Maintaining Relationships: We resist breakingsocial bonds, even bad ones.4. Ostracism: Social exclusion leads to demoralization,depression, and at times nasty behavior.
57Achievement MotivationAchievement motivation is defined as a desire forsignificant accomplishment.Skinner devised a daily discipline schedulethat led him to become the 20thcentury’s mostinfluential psychologist.KenHeyman/WoodfinCamp&Associates
58Achievement MotivationPeople with a high need to achieve tend to: choose tasks that allow for success, yet still require skill and effort, and keep persisting until success is achieved.
59Sources of Achievement MotivationWhy does one person become more motivatedto achieve than another? Parents and teachershave an influence on the roots of motivation.Emotional roots: learning to associateachievement with positive emotions.Cognitive roots: learning to attributeachievements to one’s own competence, thusraising expectations of oneself.