module 2
Bella edwards
myersep11e_lectureslides_ch05.pptxSex, Gender, and Sexuality
Chapter 5
EXPLORING PSYCHOLOGY
DAVID G. MYERS | C. NATHAN DEWALL
Gender Development
Sex
In psychology, the biologically influenced characteristics by which people define males and females.
Gender
In psychology, the socially influenced characteristics by which people define men and women.
Gender is the product of the interplay among our biological dispositions, our developmental experiences, and our current situations.
Some traits may be genetic differences; other role differences may be nurtured by culture.
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How Are We Alike? How Do We Differ? (part 1)
Each person receives 23 chromosomes from the mother and 23 from the father.
Of these 46 chromosomes, 45 are shared by men and women.
Some similarities:
Creativity, intelligence, emotions
Our “opposite” sex is, in reality, our very similar sex.
Some differences:
Self-esteem
Puberty age
Emotional expression
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How Are We Alike? How Do We Differ? (part 2)
Aggression
Any physical or verbal behavior intended to harm someone physically or emotionally
Relational aggression
An act of aggression (physical or verbal) intended to harm a person’s relationship or social standing
How Are We Alike? How Do We Differ? (part 3)
Aggression
Minor physical aggression in romantic relationships: Men and women are roughly equal.
Extreme violent acts: Men commit far more often than women.
Relational aggression: Women commit slightly more often than men.
How Are We Alike? How Do We Differ? (part 4)
Social connectedness
Boys and men are often independent; girls and women are often interdependent.
Men tend to connect perception with action; women tend to improve social relationships.
Men often prefer working with things; women often prefer working with people.
Men are more often driven by money and status; women often opt for fewer work hours and tend to have greater responsibility for family obligations.
Women more often support others; they “tend and befriend.”
The gender gap subsides by age 50.
The Nature of Gender: Biological Sex
Biology does not dictate gender, but it can influence it in two ways:
Genetically: Males and females have differing sex chromosomes.
Physiologically: Males and females have differing concentrations of sex hormones, which trigger other anatomic differences.
Prenatal Sexual Development (part 1)
Prenatal sexual development
Contribution to 23rd chromosome pair:
Mother = X chromosome
Father = X or Y chromosome
Around 7th week: Y chromosome prompts testes to develop and produce testosterone
Between 4th and 5th months: Sex hormones in fetal brain support female or male wiring
Prenatal Sexual Development (part 2)
X chromosome
Sex chromosome found in both men and women
Y chromosome
Sex chromosome found only in males
Testosterone
Both males and females have it, but females have less.
The additional testosterone in males stimulates the growth of the male sex organs in the fetus and the development of male sex characteristics during puberty.
Females have two X chromosomes; males have one X and one Y.
An X chromosome from each parent produces a female child.
When a Y chromosome is paired with an X chromosome from the mother, it produces a male child.
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Adolescent Sexual Development (part 1)
During adolescence, boys and girls enter puberty and mature sexually.
Puberty: A period of sexual maturation, during which a person becomes capable of reproducing.
Pronounced physical differences emerge.
A surge of hormones triggers a two-year period of rapid physical development.
Primary and secondary sex characteristics develop dramatically.
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Height Differences
Throughout childhood, boys and girls are similar in height.
At puberty, girls surge ahead briefly, but then boys overtake them at about age 14.
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Adolescent Sexual Development (part 2)
Primary sex characteristics
Body structures (ovaries, testes, and external genitalia) that make sexual reproduction possible
Secondary sex characteristics
Nonreproductive sexual traits, such as female breasts and hips, male voice quality, and body hair
Spermarche
First ejaculation
Menarche
First menstrual period
Body Changes at Puberty
At about age 11 in girls and age 12 in boys, a surge of hormones triggers a variety of physical changes.
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I Am Who I Am
Disorder of sexual development: A condition present at birth that involves unusual development of sex chromosomes and anatomy
Sex reassignment surgery: More common in the past; can create distress
Dramatic improvements in South African track star Caster Semenya’s race times prompted the International Association of Athletics Federations to undertake sex testing in 2009. Semenya was reported to have a disorder of sexual development, with physical characteristics not typically male or female. She was officially cleared to continue competing as a woman. Semenya declared, “God made me the way I am and I accept myself. I am who I am” (YOU, 2009).
Sex-related genes and physiology “result in behavioral and cognitive differences between males and females” (NAS, 2001). Yet environmental factors matter as well.
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The Nurture of Gender: Our Culture and Experiences (part 1)
Gender role
A role is a set of expectations (norms) about a social position
A gender role is a set of expected behaviors, attitudes, and traits for males or for females
Gender identity
Our gender identity is our personal sense of being male, female, or some combination of the two
The Nurture of Gender: Our Culture and Experiences (part 2)
Gender roles shift over time in history.
A century ago, American women could not vote in national elections, serve in the military, or divorce a husband without cause.
Gender roles vary from one place to another.
Nomadic societies of food-gathering people have little division of labor by sex.
Agricultural societies, in which women typically work in the nearby fields and men roam while herding livestock, assume more distinct gender roles.
How Do We Learn Gender? (part 1)
How do we learn our gender identity—our personal sense of being male, female, or, occasionally, some combination of the two?
Social learning theory: Proposes social behavior is learned by observing and imitating others’ gender-linked behavior and by being rewarded or punished.
Gender typing: The acquisition of a traditional masculine or feminine role. It varies from child to child, which indicates there is more to gender typing than solely observation and imitation.
How Do We Learn Gender? (part 2)
Learning to be male or female involves feeling AND thinking.
Formation of schemas helps children make sense of their world.
Gender schemas form early in life and organize experiences of male–female characteristics.
Gender expression can be seen as children drop hints in their language, clothing, interests, and possessions.
How Do We Learn Gender? (part 3)
Androgyny
Displaying both traditional masculine and feminine psychological characteristics
Transgender
Umbrella term describing people whose gender identity or expression differs from that associated with their birth sex
Hormones and Sexual Behavior (part 1)
Asexuality is having no sexual attraction to others.
Sex hormones are one of the forces that drive sexual behavior.
Testosterone: Most important male sex hormone
It is found in both males and females.
The additional testosterone in males stimulates growth of the male sex organs during fetal period, and development of the male sex characteristics during puberty
Estrogens: Sex hormones, such as estradiol, that are secreted in greater amounts by females than by males and contribute to female sex characteristics
In nonhuman female mammals, estrogen levels peak during ovulation, promoting sexual receptivity.
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Hormones and Sexual Behavior (part 2)
Large hormonal surges or declines tend to occur at two predictable points in the life span.
The pubertal-stage surge triggers development of sex characteristics and sexual interest.
In later life, hormone levels fall, with women experiencing menopause and men a more gradual change.
A third point sometimes occurs.
For some people, surgery or drugs may cause hormonal shifts.
The Sexual Response Cycle (part 1)
The sexual response cycle includes four stages of sexual responding as identified by William Masters and Virginia Johnson (1966):
Excitement
Plateau
Orgasm
Resolution
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The Sexual Response Cycle (part 2)
Excitement: The genital areas become engorged with blood, causing a woman’s clitoris and a man’s penis to swell. A woman’s vagina expands and secretes lubricant; her breasts and nipples may enlarge.
Plateau: Excitement peaks as breathing, pulse, and blood pressure rates continue to increase. Some fluid—frequently containing enough live sperm to enable conception—may appear at the tip of the penis. A woman’s vaginal secretion continues to increase, and her clitoris retracts. Orgasm feels imminent.
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The Sexual Response Cycle (part 3)
Orgasm: Muscle contractions appear all over the body and are accompanied by further increases in breathing, pulse, and blood pressure rates. The pleasurable feeling of sexual release is much the same for both sexes.
Resolution: The body gradually returns to its unaroused state as the genital blood vessels release their accumulated blood. Men then enter a refractory period that lasts from a few minutes to a day or more, during which they are incapable of another orgasm. A woman’s much shorter refractory period may enable her, if restimulated during or soon after resolution, to have more orgasms.
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Sexual Dysfunctions and Paraphilias (part 1)
Sexual dysfunctions
Impair sexual arousal or functioning
Often involve sexual motivation, especially sexual motivation and arousal
Males: Include erectile disorder and premature ejaculation
Females: Include female orgasmic disorder and female sexual interest/arousal disorder
Sometimes involve paraphilias—sexual desire directed in unusual ways (e.g., pedophilia, exhibitionism)
Sexual Dysfunctions and Paraphilias (part 2)
Sexual dysfunction
Problem that consistently impairs sexual arousal or functioning
Erectile disorder
Inability to develop or maintain an erection due to insufficient blood flow to the penis
Premature ejaculation
Sexual climax that occurs before the man or his partner wishes
Sexual Dysfunctions and Paraphilias (part 3)
Female orgasmic disorder
Distress due to infrequently or never experiencing orgasm
Paraphilias
Sexual arousal from fantasies, behaviors, or urges involving nonhuman objects, the suffering of self or others, and/or nonconsenting persons
Sexual Dysfunctions and Paraphilias (part 4)
American Psychological Association (2013)
Classifies people as disordered only if they experience sexual desire in unusual ways and:
The person experiences distress from unusual sexual interest or
The desire entails harm or risk of harm to others
Paraphilias include necrophilia, exhibitionism, and pedophilia.
Sexually Transmitted Infections (part 1)
Sexually transmitted infection (STI)
Also called sexually transmitted disease (STD)
Every day, more than 1 million people worldwide acquire an STI.
AIDS (acquired immune deficiency syndrome)
A life-threatening, sexually transmitted infection
Caused by the human immunodeficiency virus (HIV)
Depletes the immune system and leaves the person vulnerable to infections
Sexually Transmitted Infections (part 2)
CDC report: Sexually active 15- to 24-year-olds are at higher risk for STIs than older adults.
Condom use effectiveness varies by infection (80 percent effectiveness against transmission of HIV when used with infected partner; less effective with skin-to-skin STIs such as herpes).
Worldwide, women’s AIDS rates are increasing fastest, partly because the virus is passed from man to woman much more often than from woman to man.
Biopsychosocial Influences on Sexual Motivation
Compared with our motivation for eating, our sexual motivation is less influenced by biological factors. Psychological and social-cultural factors play a bigger role.
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The Psychology of Sex: External Stimuli
Research indicates exposure to sexually explicit material has adverse effects in three ways:
Believing rape is acceptable
Reducing satisfaction with a partner’s appearance or with a relationship
Desensitization
The Psychology of Sex: Imagined Stimuli
Imagined stimuli
Sexual desire and arousal can be imagined; the brain has been called the most significant sex organ.
People with spinal cord injury have reported feeling sexual desire.
Approximately 95 percent of people report having sexual fantasies.
Male fantasies tend to be more frequent, more physical, and less romantic than female fantasies.
Sexual Risk Taking and Teen Pregnancy (part 1)
Environmental factors that influence a higher teen pregnancy rate:
Communication about birth control
Impulsivity
Alcohol use
Mass media: Norms of unprotected promiscuity; media help write the social scripts that affect our perceptions and actions
Sexual Risk Taking and Teen Pregnancy (part 2)
Factors that predict sexual restraint:
High intelligence
Religious engagement
Father presence
Participation in service learning programs
Sexual Orientation
Sexual orientation is the enduring sexual attraction toward:
Members of one’s own sex (homosexual orientation)
The other sex (heterosexual orientation)
Both sexes (bisexual orientation)
In all cultures, heterosexuality has prevailed but homosexuality has existed. Where same-sex relationships are illegal, the prevalence of people who are lesbian, gay, or bisexual is no different.
Sexual Orientation: The Numbers
Survey results vary by survey methods and population; less open responses are found in less tolerant places.
Exclusively homosexual: 3 to 4 percent of men and 2 percent of women.
In the United States, 5 percent of men and 13 percent of women report some same-sex sexual contact during their lives.
APA (2009): Efforts to change sexual orientation are unlikely to be successful and involve some risk of harm.
Women’s sexual orientation tends to be less strongly felt and potentially more fluid; their sexual activity level also varies more.
Origins of Sexual Orientation (part 1)
Homosexuality is not linked to problems in parent–child relationships, does not involve a fear or hatred of the other sex, and is not significantly linked to childhood sexual victimization.
There is a lack of evidence for environmental causes of homosexuality.
Instead, homosexuality seems to have biological influences, as investigated in studies of same-sex behavior in other species, gay–straight brain differences, genetic influences, and prenatal influences.
Origins of Sexual Orientation (part 2)
Same-sex attraction in other species
Same-sex behavior has been observed in several hundred species—for example, swans, penguins, grizzlies, gorillas, monkeys, flamingos, and owls.
Gay–straight brain differences
One hypothalamic cell cluster is smaller in women and gay men than in straight men.
The anterior commissure is larger in gay men than in straight men.
Gay men’s hypothalamus reacts in the same way as straight women’s hypothalamus to the smell of sex-related hormones.
Origins of Sexual Orientation (part 3)
Genetic influences
Shared sexual orientation is higher among identical twins than among fraternal twins.
Sexual attraction in fruit flies can be genetically manipulated.
Male homosexuality often appears to be transmitted from the mother’s side of the family.
Origins of Sexual Orientation (part 4)
Prenatal influences
Altered prenatal hormone exposure may lead to homosexuality in humans and other animals.
Men with several older biological brothers are more likely to be gay, possibly due to a maternal immune-system reaction.
The consistency of the brain, genetic, and prenatal findings clearly leads to a biological explanation of sexual orientation.
The Older Brother Effect
Researcher Ray Blanchard (2008a) offers these approximate curves depicting a man’s likelihood of homosexuality as a function of his number of older brothers. This correlation has been found in several studies, but only among right-handed men (as about 9 in 10 men are).
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Gay–Straight Trait Differences
| Research indicates that homosexuals and heterosexuals differ in the following traits: | |
| Spatial abilities Fingerprint ridge counts Auditory system development Handedness Occupational preferences Relative finger lengths | Age of onset of puberty in males Birth size and weight Sleep length Physical aggression Walking style Gender nonconformity |
On average (the evidence is strongest for males), results for gays and lesbians fall between those of straight men and straight women. Three biological influences—brain, genetic, and prenatal—may contribute to these differences.
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Spatial Abilities and Sexual Orientation
Which of the three figures can be rotated to match the original figure? Straight males tend to find this type of mental rotation task easier than do straight females, with gays and lesbians falling in between.
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Male–Female Differences in Sexuality
Cross-culturally, men think more than women about sex, and men are more likely to think that casual sex is acceptable.
Why might natural selection have resulted in greater male promiscuity?
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Compared with lesbians, gay men (like straight men) report more interest in uncommitted sex, more responsiveness to visual sexual stimuli, and more concern with their partner’s physical attractiveness.
Gay male couples report having sex more often than do lesbian couples.
Men who have the trait of promiscuity are more likely to have their genes continue, and even spread, in the next generation. There is little cost to spreading their genes.
For women, a trait of promiscuity does not greatly increase the number of babies, and would have greater survival costs. Historically, pregnancy was often life-threatening.
An Evolutionary Explanation of Human Sexuality: Male–Female Differences in Sexuality
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Predict the Responses
| Researchers asked samples of U.S. adults whether they agreed or disagreed with the following statements. For each item, give your best guess about the percentage who agreed with the statement.2 | ||
| Statement | Percentage of males who agreed | Percentage of females who agreed |
| If two people really like each other, it’s all right for them to have sex even if they’ve known each other for a very short time. | ----- | ----- |
| I can imagine myself being comfortable and enjoying “casual” sex with different partners. | ----- | ----- |
| Affection was the reason I first had intercourse. | ----- | ----- |
| I think about sex every day, or several times a day. | ----- | ----- |
| Pornography is “morally acceptable.” | ----- | ----- |
Natural Selection and Mating Preferences
Men prefer women with signs of future fertility (narrow waist and fuller figure; age of peak fertility).
Women prefer men with loyal behavior and physical/social power and resources.
Why might natural selection have resulted in these mating preferences?
Male choices optimized the chance of producing offspring.
Female choices optimized offspring survival.
Men chose widely; women chose wisely!
Critiquing the Evolutionary Perspective
Most psychologists agree that natural selection prepares humans for survival and reproduction.
Critics of evolutionary psychology research note these limitations:
Evolutionary psychology starts with an effect and works backward to explain what happened.
More immediate explanations are better understood through social learning theory (including social scripts) than through decisions made by our distant ancestors.
Social consequences of evolutionary explanation are problematic.
Some traits and behaviors are difficult to explain by natural selection.
Sex and Human Relationships
Human sexuality research does not aim to define personal meaning of sex, but one significance of such intimacy is its expression of our profoundly social nature.
For both men and women, but especially for women, orgasm occurs more often when sex happens in a committed relationship rather than in a sexual hookup.
Sex is a socially significant act. Achieving orgasm alone is less satisfying, with much less of a surge in the prolactin hormone (associated with sexual satisfaction and satiety), than after sex with a loved one.
Thanks to overlapping brain reward areas, sexual desire and love feed each other.
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Reflections on the Nature and Nurture of Sex, Gender, and Sexuality
Our ancestral (genetic) history helped form humans as a species; where there is variation, natural selection, and heredity, there will be evolution.
Our culture and experiences also form us.
In many modern cultures, gender roles are merging.
Swift changes in gender roles and sexual attitudes have occurred since 1960.
Biology does not fix gender roles.
We cannot excuse our failings by blaming them solely on bad genes or bad influences. In reality, we are both the creatures and the creators of our worlds.
