1. Gender and Sexuality Chapter 4

2. 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

3. 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

4. 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

5. 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?

6. 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

7. 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

8. 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

9. 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

10. 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

11. 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

12. 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

13. 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

14. 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.

15. 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.

16. 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

17. 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

18. Theories of Gender Typing

19. Human Sexuality Sexual Motivation The Physiology of Sex
The Psychology of Sex

20. 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

21. 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

22. 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

23. Sexually Transmitted Infections
Rates of STIs (aka STDs) are rising
Two-thirds of infections occur in people under 25
Partners
“Phantom” partners

24. 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

25. 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

26. 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.

27. 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.

28. Sexual Orientation Sexual Orientation
Environment and Sexual Orientation
Biology and Sexual Orientation

29. 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

30. Fewer than 1% reported being actively 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.

31. 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)

32. 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.

33. 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.

34. 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.

35. 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

36. 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.

37. 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.

38. 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.

40. An Evolutionary Explanation of Human Sexuality
Evolutionary Psychology and Human Sexuality
Gender Differences in Sexuality
Natural Selection and Mating Preferences
Critiquing the Evolutionary Perspective

41. 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

42. 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.

43. 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)

44. 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.

45. 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.

46. 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.