460 likes | 712 Vues
Gender and Sexuality Chapter 4. Gender and Sexuality. Gender Development How are We Alike? How Do We Differ? The Nature of Gender: Our Biology The Nurture of Gender: Our Culture. Gender and Sexuality: Overview of Topics. Human Sexuality The Physiology of Sex The Psychology of Sex
E N D
Gender and Sexuality Gender Development • How are We Alike? How Do We Differ? • The Nature of Gender: Our Biology • The Nurture of Gender: Our Culture
Gender and Sexuality: Overview of Topics Human Sexuality • The Physiology of Sex • The Psychology of Sex Sexual Orientation • Environment and Sexual Orientation • Biology and Sexual Orientation
Gender and Sexuality: Overview of Topics An Evolutionary Explanation of Human Sexuality • Gender Differences in Sexuality • Natural Selection and Mating Preferences • Critiquing the Evolutionary Perspective Thinking About Gender, Sexuality, and Nature-Nurture Interaction
Defining Gender • Your biological sex is the basis for defining your gender, the characteristics our society defines as male or female • How are the two genders alike? • How are they different? • How much does biology play a role in gender characteristics?
Gender Similarities and Differences • Men and women are alike: • No differences in intelligence or senses. Of the 46 chromosomes, 45 are unisex • There are also many differences. Examples: • Age of puberty, lifespan, body fat, muscle mass, height. • Women are more emotional, more altruistic, more prone to depression and anxiety • Men are more prone to suicide, alcoholism, color-blindness, autism, and ADHD
Gender Differences in Aggression Men express themselves and behave in more aggressive ways than do women. This gender gap in (physical) aggression appears in many cultures and at various ages. • Men are arrested for murder 10 times more than women in the US • Fighting, warring, and hunting are primarily male activities throughout the world
Gender and Social Power • In most societies, men are socially dominant and are perceived as such. • In 2009, men accounted for 82% of the seats in the world’s governing parliaments. • Men tend to be more directive and authoritarian, women more democratic • With age, these gender differences tend to decrease
Gender Differences and Social Connectedness • Young and old, women are more concerned with social connections (friendships) with people than do men. • Men enjoy doing activities side-by-side and talk to others to communicate solutions • Women enjoy talking face-to-face, and often talk to explore relationships. As friends, women talk more often and more openly
The Nature of Gender: Our Biology • Biology influences gender in two ways: • Genetically, through differing sex chromosomes • Physiologically, from different concentrations of sex hormones • Evolutionary psychology: the study of how our behavior and mind have changed in adaptive ways over time through the process of natural selection
Biological Influence on Gender: Genes • Your sex was determined by your father’s contribution the the 23rd pair of chromosomes – the sex chromosomes • X chromosomes are found in both men and women. Females have two, men have an X and a Y. • Y chromosomes are found only in males
Biological Influence on Gender: Prenatal Development • At about the 7th week after conception, the Y chromosome causes the testes to develop and to produce testosterone, the most important male sex hormone. • Key period: fourth and fifth prenatal months • Sex hormones bathe the fetal brain and influence its wiring • High fetal testosterone can produce females with more masculine muscular and skeletal features
Biological Influence on Gender: Brain Differences • Part of frontal lobe, used for verbal fluency, is thicker in females • Part of parietal cortex, used for space perception, is thicker in males
Sexual Differentiation Sexual differentiation is not only biological, but also psychological and social. However, genes and hormones play a very important role in defining gender, especially in altering the brain and influencing gender differences as a result.
The Nature of Gender: Our Culture • Our culture shapes our gender roles— expectations of how men and women are supposed to behave. • Gender roles can smooth social relationships, and vary from culture to culture Gender Identity— one’s sense of being male or female.
Transgendered Individuals • Some individuals are transgendered – their gender identity feels mismatched with their biological sex • Stu Rassmussen, the mayor of Silverton, Oregon, is openly transgendered
How do we learn to be male or female? • Social Learning Theory proposes that we learn gender behavior like any other behavior—reinforcement, punishment, and observation. • However, social learning may not fully explain gender typing – some children are more attuned than others to traditional gender roles • Children form gender schemas at an early age – frameworks for understanding male-female characteristics
Human Sexuality Sexual Motivation • The Physiology of Sex • The Psychology of Sex
Hormones and Sexual Behavior • Testosterone: main male sex hormone • Estrogens: main female sex hormones • Sex hormones are important at several stages: • During prenatal period, they direct development as males or females • During puberty, a surge in sex hormones ushers us into adolescence • As adults, sex hormones help activate sexual behavior
Hormones and Sexual Behavior • High estrogen levels (injected or with ovulation) go with increased sexual receptivity • Human females with partners have increased sexual initiative behavior around ovulation • Men’s testosterone levels increased when exposed to the scent of an ovulating woman or during social encounters with females • Restoring testosterone levels in women (after removal of ovaries) can restore sexual desire
The Sexual Response Cycle • Masters and Johnson (1960s) identified a four-stage sexual response cycle: • Excitement • Plateau • Orgasm • Resolution Men then enter a refractory period, a resting period during which they cannot achieve another orgasm
Sexually Transmitted Infections • Rates of STIs (aka STDs) are rising • Two-thirds of infections occur in people under 25 Partners “Phantom” partners
Less Sex, More Pregnancy • Compared with Europe, US teens have lower rate of intercourse but higher rates of pregnancy and abortion which denotes lower rates of contraceptive use in the US. • Why? • Guilt about sex may prevent planned sex but do not prevent impulsive (unprotected) sex • Discomfort about discussing birth control prevents education • Alcohol use goes with lack of sexual restraint • Peers and media model unprotected sex
The Psychology of Sex • Hormones like testosterone are like fuel in a car –without the right levels of hormones, there is no drive (sexual interest and sexual response). • However, our sexual motivation requires more than hormones, it requires stimuli: • External Stimuli • Imagined Stimuli • Both involve images and stories
External Stimuli Studies confirm that men, and to a lesser extent, women become sexually aroused when exposed to erotic material. Repeated exposure to sexual images can reduce the erotic response and the attraction to one’s partner.
Imagined Stimuli Our imagination can influence sexual arousal and desire. People with spinal cord injuries and no genital sensation can still feel sexual desire. 95% of men and women report having sexual fantasies. Men fantasize about sex more often, more physically, and less romantically.
Sexual Orientation Sexual Orientation • Environment and Sexual Orientation • Biology and Sexual Orientation
Sexual Orientation Sexual orientation refers to a person’s enduring pattern of sexual attraction toward with members of either their own sex or the other sex. Homosexual Heterosexual Bisexual
Sexual Orientation According to one survey (Mosher, 2005), 3 or 4% of men and 1 or 2% of women reporting being exclusively homosexual. Fewer than 1% reported being actively bisexual. Many people surveyed said they have had an occasional homosexual fantasy. As members of a minority who face isolation, discrimination, and ridicule, homosexuals often struggle with how to address their sexual orientation.
Sexual Orientation • Most psychologists today view homosexuality as neither willfully chosen, nor willfully changed • Homosexuality is not, in and of itself, associated with mental disorders or emotional or social problems • Homosexuality met with bullying, and harassment, however, can lead to depression and risk of suicide (Sandfort, 2001, Warner, 2004)
Environment and Sexual Orientation • Homosexuality is NOT linked with problems in a child’s relationships with parents • Homosexuality does NOT involve a fear or hatred of people of the other gender • Sexual orientation is NOT linked with current levels of sex hormones in the blood • As children, most homosexuals were NOT molested or otherwise sexually victimized by an adult homosexuality • The bottom line: if there are environmental factors that influence sexual orientation, we do not yet know what they are.
Same-Sex Attraction in Other Species A number of animal species are devoted to same-sex partners, suggesting that homosexuality exists in the animal world.
Biology and Sexual Orientation Homosexuality is more likely based on biological factors like differing brain centers, genetics, and parental hormone exposure rather than environmental factors.
Gay-Straight Brain Differences • A cluster of cells in the hypothalamus is reliably larger in heterosexual men than in women and homosexual men (Levay, 1991) • Not an “on-off button” for sexual orientation, but an important part of the brain pathway for sexual behavior • Other studies have since reported additional gay-straight brain differences
Genetic Influence on Sexual Orientation Family: Homosexuality seems to run in families. Twin studies: Identical twins are more likely than fraternal twins to share a homosexual orientation. However, they don’t always do so, suggesting other factors than just genes alone. Fruit flies: Researchers altered a single gene, leading females to act like males during courtship and males to act like females.
Biology of Sexual Orientation: Prenatal Environment • Exposure to hormones in months 1 ½ -4 ½ for fetuses of either sex: • Female hormones may increase attraction to males • Testosterone may increase homosexuality. • Mother’s possible immune defense against males: • The more male fetuses that have been in a womb previously (older brothers), the more likely the next male fetus will be homosexual. • Not true for adopted brothers; only true for right-handed men.
Gay-Straight Differences • Homosexual individuals of both sexes fall halfway between heterosexual men and women on several traits, including spatial problem-solving abilities, as shown in this chart.
An Evolutionary Explanation of Human Sexuality Evolutionary Psychology and Human Sexuality • Gender Differences in Sexuality • Natural Selection and Mating Preferences • Critiquing the Evolutionary Perspective
Evolutionary Psychology • Throughout human history, those with trait characteristics that helped them to survive and reproduce better were more likely to pass on those traits This adaptive process is called natural selection • Men who were attracted to young, healthy women produced more offspring, which may explain why men today have eyes for women whose age and features imply fertility
Mating Preferences Males look for youthful appearing females in order to pass their genes into the future. Females, on the other hand, look for maturity, dominance, affluence, and boldness in males. Data based on 37 cultures.
Gender Differences in Sexuality • Men have higher sex drive and are more interested in casual sex • Men have a more recreational approach to sex, women have a more relational approach • Thus, gay men have more sex than lesbians, but lesbians have married more than gay men (where legal)
Natural Selection & Mating Preferences Natural selection has caused males to send their genes into the future by attempting to mate with multiple females since males have lower costs involved with rearing offspring. However, females tend to prefer a mature and caring male because of the higher costs involved with pregnancy and nursing – long-term mates contribute caring and support, giving their offspring greater chances.
Critiquing the Evolutionary Perspective Evolutionary psychologists take an effect and work backward to explain it in terms of natural selection. Some worry about the social consequences of the evolutionary view. Are genes our destiny? Are efforts to remake society useless? Culture matters. Socialization can instill values such as monogamy in men or promiscuity in women. Cultural expectations influence mate preferences.
Evolutionary Psychologists Reply Evolutionary psychology is not just retrospective; it leads to predictions that can be tested. Evolutionary psychologists remind us how we have adapted, but do not dictate how we ought to be. Humans behavior is less hardwired by our genes than in other species. Rather, we have a tremendous capacity for learning which has helped us survive.