Human sexuality midterm study guide–

Cultural Considerations in Human Sexuality

• Similarities between Religions Regarding Human Sexuality

  • Sex within Marriage: All religions view sex as appropriate within marriage.

  • Control of Sexuality: Regulation of sexual behavior is common, prohibiting adultery.

  • Sexual Modesty: Emphasis on modesty and restraint in sexual behavior.

  • Adultery Prohibited: General disapproval of adultery across religions.

  • Recognition of Sexual Diversity: Recognition of different sexual identities, especially in Hinduism.

• Reasons for These Similarities:

  • Need to maintain social order, family stability, and protect against harm (such as disease).

  • Religions often reflect societal needs concerning human sexuality.

• Human Universals:

  • Defined as features or behaviors common to all cultures.

  • Five Human Universals:

    • Sexual Attraction

    • Sexual Modesty

    • Rape and Rape Condemnation

    • Romantic Love

    • Incest Taboos

Overview of Sexology

• Kinsey’s Research Practice:

  • Used trained interviewers and nuanced questions to normalize sexual behavior and reduce shame, helping participants open up during interviews.

Evolution of Sex

• Sexual vs. Asexual Species:

  • Sexual Species: Require two sexes (male and female) to combine genetic material (sperm and egg), promoting genetic diversity.

  • Asexual Species: Reproduce independently, creating genetically identical offspring.

• Cost of Males:

  • In sexually reproducing populations, only females can gestate offspring, leading to a situation where males contribute less to reproduction (termed 'cost of males').

• Extinction of Asexual Species:

  • They accumulate harmful mutations over generations due to lack of genetic recombination, leading to decreased genetic fitness and eventual extinction.

• Importance of Sexual Reproduction:

  • Allows genetic recombination, reducing the accumulation of harmful mutations, aiding survival and adaptation.

• Fisher-Muller Hypothesis:

  • Suggests that sexual reproduction helps rapidly combine beneficial mutations, enhancing survival and fitness.

• Muller’s Ratchet:

  • A process which describes how asexual populations accumulate harmful mutations over time due to lack of genetic recombination.

• Red Queen Hypothesis:

  • States that continuous evolution is necessary to stay ahead of predators, parasites, and competitors.

  • Promotes the advantages of sexual reproduction through genetic diversity.

• Anisogamy:

  • Refers to the fusion of dissimilar gametes (small, mobile sperm and large, nutrient-rich eggs), creating two distinct sexes with different reproductive strategies.

Gamete Size and Sexual Strategies

• Small Gametes (Sperm):

  • Pros: Cost-effective, fast, and mobile, allowing males to produce numerous offspring.

  • Cons: Lack nutrients for zygote development and face high competition.

• Large Gametes (Eggs):

  • Pros: Contain necessary nutrients for developing zygote; higher survival rates.

  • Cons: Costly to produce, immobile, and require longer development.

• Why Midsize Gametes Don’t Work:

  • Midsize gametes lack competitiveness and necessary nutrients; thus, natural selection favors extremes (small and large).

• Impact of Gamete Size on Sexual Strategies:

  • Small gametes lead to a quantitative strategy (more sperm), while large gametes lead to a qualitative strategy (selective mating).

Sexual Selection

• Definition:

  • A type of natural selection where traits enhance mate attraction and reproduction, regardless of survival benefits.

• Competition Types:

  • Intersexual Competition: One sex (usually females) chooses mates (e.g., based on beauty).

  • Intrasexual Competition: Same sex competes directly for mates (e.g., males fighting for female attention).

Dual Selection and Sexual Dimorphism

• Dual Selection: Both natural and sexual selection influence traits affecting survival and mate attraction.

• Sexual Dimorphism: Differences between male and female species often shaped by sexual selection (size, appearance).

Mate Choice and Assortative Mating

• Males’ Mate Valuation:

  • Prioritize physical attractiveness and youth, which signal fertility.

• Females’ Mate Valuation:

  • Value resources, status, and reliability, essential for offspring upbringing.

• Parental Investment:

  • Time/resources spent on raising offspring, crucial for mate choice due to its impact on offspring success.

• Grandmother Hypothesis:

  • Suggests older women enhance grandchildren's survival chances, explaining longevity beyond reproductive years.

• Mate Choice Across Orientations:

  • Influenced by similar factors (attraction, resources), though preferences may vary across orientations and genders.

• Monogamy in Humans:

  • Prevalent due to high parental investment needs, benefiting from two caregivers.

• Polyamory in Humans:

  • Reflects differing reproductive strategies and social arrangements, explaining cooperation benefits through game theory.

Assortative Mating

• Definition:

  • Tendency to pair with others sharing similar traits (appearance, intelligence).

• Traits of Importance:

  • Physical appearance and personality are most influential; traits like political views may be lesser factors.

Sexual Anatomy

• Five Anatomical Features:

  • Testes: Produce sperm and testosterone.

  • Ovaries: Produce eggs and hormones.

  • Penis: Delivers sperm during intercourse.

  • Vagina: Receives sperm; birth canal.

  • Uterus: Houses and nourishes developing fetus.

• Sperm Count Decline:

  • Due to endocrine disruptors, environmental toxins, and lifestyle changes.

  • Declining at a rate of ~1% annually.

• Impact of Endocrine Disruptors:

  • Interfere with hormonal production, affecting sexual development and fertility.

Chromosomal Disorders and Sexual Response

• Sexual Differentiation:

  • Process of developing male or female characteristics based on chromosomes and hormones.

• Key Genes and Hormones:

  • SRY gene (Y chromosome) initiates male differentiation.

  • Testosterone and AMH guide male traits; estrogen influences female traits.

• Genital Tubercle & Urogenital Folds:

  • Genital tubercle develops into the penis (males) or clitoris (females).

  • Urogenital folds become scrotum (males) or labia (females).

Intersex Conditions

• Definition:

  • Intersex refers to individuals with physical characteristics that do not fit typical definitions of male or female.

• Key Causes of Intersex Diagnosis:

  • Chromosomal Abnormalities: E.g., Turner Syndrome (45,X) affecting females or Klinefelter Syndrome (47,XXY) affecting males.

  • Hormonal Imbalances/Insensitivity: E.g., AIS leads to atypical physical traits.

  • Congenital Adrenal Hyperplasia (CAH): Excess androgen production causing virilization.

• Detailed Features of Intersex Conditions:

  • Turner Syndrome (45, X): Short stature, infertility, webbed neck, affects females.

  • Klinefelter’s Syndrome (47, XXY): Reduced testosterone, breast development, affects males.

  • Triple X Syndrome (47, XXX): Often mild symptoms in females.

  • Jacobs Syndrome (47, XYY): Taller height, acne in males.

  • Androgen Insensitivity Syndrome (AIS): XY individuals with female characteristics.

  • Congenital Adrenal Hyperplasia (CAH): Hormonal disorder affecting both sexes.

Sexual Response Models

• Masters and Johnson Model:

  • Stages:

    • Excitement: Initial arousal

    • Plateau: Increased arousal tension preceding orgasm.

    • Orgasm: Peak pleasure experience.

    • Resolution: Body returns to baseline.

• Vasocongestion: Increased blood flow causing swelling and erection.

• Myotonia: Muscle tension/contractions during arousal.

• Triphasic Model: Adds a desire phase separate from excitement.

• Dual Control Model: Focus on the balance of excitation (arousal triggers) and inhibition (factors preventing arousal).

• Erotic Stimulus Pathway Theory:

  • Stages include: Seduction, Sensations, Surrender, Reflection.

  • Critiqued for being overly psychological.

Sexual Dysfunction

• Definition of Sexual Dysfunctions:

  • Difficulties preventing fulfilling sexual experience, including issues with desire and arousal.

• Spectatoring: Mental observation during sex, potentially hindering pleasure and contributing to dysfunction.

• Importance of Treatability: Understanding that sexual dysfunctions are curable can alleviate stigma, promoting treatment seeking.

• Dopamine and Sexual Dysfunction:

  • Plays a key role in pleasure and motivation. Imbalances affect desire/arousal negatively.

• Prolactin's Role: High levels can reduce libido and lead to sexual dysfunctions.

• Serotonin's Impact: Affects mood/arousal; imbalances may lead to various sexual dysfunctions.

• Neuroticism's Influence: High levels can increase anxiety during sex, negatively impacting desire and performance.

• Conscientiousness and Extraversion Impacts:

  • Conscientiousness relates to better sexual health practices, whereas extraversion can enhance communication but risks compulsive behaviors.

• Agreeableness in Relationships: High levels improve communication and intimacy, potentially reducing dysfunction.

• Narcissism Effects: Can create unrealistic expectations and hinder emotional connections, contributing to dysfunction.

• Types of Sexual Dysfunction:

  • Male hypoactive sexual desire disorder (HSDD) and female sexual interest/arousal disorder, among others.

Attraction and Arousal

• Scarcity Effects: The greater the unavailability of a person, the higher their desirability, prompting more significant investment of time/resources to gain their attention.

Misattribution of Arousal**:

• Mistakenly attributing arousal to incorrect sources, enhancing attraction.

• Proximity and Attraction: Close proximity increases relationship likelihood through mere exposure effects.

• Major Histocompatibility Complex (MHC):

  • Influences mate attraction; individuals prefer partners with dissimilar MHC alleles for increased immune diversity in offspring.

• Birth Control Effects on MHC Preference: Women on hormonal birth control show a preference for men with similar MHC alleles, unlike their general preference.

Love and Relationships

• Components of Love:

  • Intimacy: Emotional closeness.

  • Passion: Physical attraction.

  • Commitment: Decision to maintain the relationship.

• Types of Love:

  • Infatuation, romantic love, liking, companionate love, fatuous love, and consummate love based on combinations of the three components.

• Attachment Styles:

  • Secure: Trust and comfort.

  • Anxious: Dependency issues.

  • Avoidant: Emotional distance.

• Impact of Parenting Styles on Attachment:

  • Authoritative style promotes secure attachment; authoritarian and permissive styles can lead to insecure attachments.

• Relationship Satisfaction Cycle: Satisfaction may peak at the beginning and plateau or decline over time due to communication and frequency changes.

Common Communication Styles**:

• Critical, contemptuous, defensive, and stonewalling behaviors disrupt relationship dynamics.

• Ideal Sexual Frequency: Generally once a week; however, mutual satisfaction and communication are key.