Human Sexuality and Motivation Quiz

Affective Psychology: The Motive of Sex

• Sexuality is a primary motivational system for race preservation. Success in reproduction is linked to the act of making love, not war.
• Biological regulation of sexuality:
  • Hormonal regulation becomes less important during phylogenesis (evolutionary development).
  • Central Nervous System (CNS) regulation is crucial in humans, evidenced by the role of sex fantasies in arousal.
  • Learning and previous experiences become more important in evolutionary development (e.g., Harlow experiments).
  • Cultural factors are also vitally important.
• Cognitive regulation is important in humans due to the role of sex fantasies in sexual arousal.
• Learning and previous experiences play a larger role in human sexual development compared to other species.
• Cultural influences deeply affect human sexuality.

Sexuality as an Element in Intimate Relationships

• A study by Cain et al. (2003) of thousands of women revealed that most (around 90%) are motivated to show their love when engaging in sexual activity.
• Other significant motivations reported by women included:
  • 80% reported enjoying pleasure
  • 70% reported fulfilling their partner's desire
  • 60-70% felt that sex reduced tension/stress
  • A very small percentage (around 1-2%) responded that they wished to have a baby.
• Human sexuality is a key aspect in forming and maintaining pair-bonding.

Determinants of Sexual Identity

• Genes
• Hormones
• Environment

Early Sexual Development

• Genes: At the beginning of development of a fetus, or about the first couple of months after conception, the chromosomes determine whether the baby will develop into a male or a female.
  • XX chromosomes indicate the embryo will develop into a female.
  • XY chromosomes indicate the embryo will develop into a male.
• Genetic disorders can affect this process
• Example: Monosomy XO can result in Turner syndrome.

Adult Sexuality: Hormones

• Steroid hormones
  • "Male sex hormones" and "female sex hormones" are actually produced in both sexes.
  • Testosterone:
    • The primary androgen (male hormone).
    • Produced mainly in the testes (men), but smaller amounts are also secreted by adrenal glands in men and women.
    • Men typically produce significantly more testosterone than women.
  • Estrogen:
    • The main female sex hormone.
    • Produced in the ovaries and placenta (women) as well as in smaller quantities in the testes (men) and adrenal glands (both).
    • Testes produce much less estrogen than the ovaries
• Neuropeptide hormones:
  • Oxytocin;
    • Acts as a hormone and neurotransmitter.
    • Produced in the hypothalamus and secreted by the pituitary gland in the brain (men and women).
    • Also secreted in the ovaries (women) and testes (men).
    • Influences erotic and emotional attraction (often called the "love hormone").

Testosterone in Sexual Behavior

• Linked to male sexual desire (libido)
• May have a less direct impact on sexual functioning
• Lower testosterone levels (in men) can still result in full erections and orgasms, but a reduced interest in sex.
• Evidence from research using castration studies and medication in men:
  • Reduction of sexual desire and activity.
  • Use in medical treatments of conditions, such as prostate cancer.
• In women:
  • Important for sexual desire and arousal.
  • Testosterone replacement therapy can significantly increase sexual desire and arousal, especially in postmenopausal women.
  • Supplementary testosterone can increase genital responsiveness within hours.

Estrogens in Sexual Behavior

• Role is still not completely clear
• In males:
• Important for fertility and sexual function, may be associated with nerve cells in the brain controlling territory defense in mice
• In females:
• Contribute to a general sense of well-being; low levels of estrogen are linked to low mood and postpartum/peri-menopausal depression.
• Also maintain thickness/elasticity of vaginal lining and may be linked to vaginal lubrication.

How much testosterone is necessary for normal sexual functioning

• Levels of free testosterone are much lower in women than in men.
• Women's body cells are more sensitive to testosterone than men's.
• Testosterone levels decline with age in both sexes.

Oxytocin in Male and Female Sexual Behavior

• Released during physical intimacy and touch
• Increases skin sensitivity to touch
• High levels associated with orgasm.
• High levels thought to contribute to emotional and erotic bonding.
• Important for facilitating social attachments and feelings of love (e.g., mother-child bonding)
• Stress lowers oxytocin levels.

The Brain and Sexual Arousal

• Sexual arousal can occur without sensory stimulation (thoughts and fantasies).
• Factors that are considered attractive vary greatly depending on culture.
• Cultural conditioning plays a major role in determining the stimuli individuals find arousing (e.g., some cultures find bare breasts erotic, while others do not).

Anatomical Regions of the Brain Involved in Sexual Arousal and Response

• Cerebral cortex
  • The “thinking center” of the brain.
• Limbic system
  • Associated with emotions, motivation, and memory.
  • Structures include: hypothalamus, hippocampus, amygdala, and cingulate gyrus.
• Stimulation of certain areas of the limbic system leads to intense sexual pleasure in humans.
• Damage to specific hypothalamic areas can significantly reduce sexual behavior in various species.

Neurotransmitters and Sexual Arousal

• Dopamine:
  • Released in the pleasure center of the limbic system.
  • Facilitates sexual arousal and response. -Testosterone stimulates dopamine release in both men and women.
• Oxytocin
  • Already discussed
• Serotonin:
  • Inhibits sexual activity.
  • Inhibits the release of dopamine.
  • Antidepressants that increase serotonin levels (SSRIs) can decrease libido and sexual response.

Sexual Arousal: The Role of the Senses

• Touch:
  • Primary erogenous areas contain high concentrations of nerve endings.
  • Secondary erogenous zones are areas that become erotically sensitive through experience.
• Vision:
  • Males are often more aroused by visual stimuli than females.
  • This is influenced by social conditioning (view of pornography, expectations).
• Smell:
  • Highly influenced by a person’s past experiences and social conditioning. Some cultures consider the smell of genital secretions a sexual stimulant.
  • Other individuals note a desire for people with whom they feel an attraciton toward or whom they are physically intimate with.
• Hearing:
  • Highly variable.
  • Some find words, erotic conversation, moans, etc., to be arousing.
  • Others prefer quiet or intimacy.
• Taste:
  • Plays a minor role in arousal.

Aphrodisiacs and Anaphrodisiacs

• Aphrodisiacs are substances alleged to increase sexual desire and activity (e.g., bananas, asparagus, and ground-up animal horns). Foods of this kind rarely have any effect.
• Certain drugs (e.g., some stimulants and depressants) can increase or decrease sexual desire or responses depending on the dose and properties of the agent.
• Anaphrodisiacs lessen or inhibit desire and libido (e.g., birth control pills, opiates, tranquilizers, nicotine, and some blood pressure medications, drugs treating heart disease, antidepressants, anticonvulsants, and antipsychotics).

The Sexual Response: Masters & Johnson

• Masters and Johnson recorded physiological data from 382 women and 312 men from 1957-1965.
• Their research focused on the physiological responses of the human body during sexual activity.
• They recorded data on masturbation and sexual intercourse; developed a 4-stage model of human sexual response.

Masters & Johnson's Four-Stage Model of Sexual Response

• Excitement
• Plateau
• Orgasm
• Resolution.
• Note: There are lot's of variations in individual experiences.

Sexual Response Cycle Differences Between the Sexes

• Women are more varied in their response than men:
• Women can have multiple orgasms in a single sexual session, often without a refractory period.
• Males have a refractory period after orgasm, which can range from a few minutes to hours.

Sexual Attraction

• Facial metrics
• Body metrics are important in sexual attraction (e.g., waist to hip ratio).
• Female and male preference (cultural differences on ideals).
• Dove's campaign for real beauty (Focus on average women, not ideal physical standards)

Useful Links

• Thabiso M'Timkulu's website for his course on Human Sexuality
• McGraw-Hill Human Sexuality Image Bank
• Naked Science Video on What is sexy?

Test your knowledge on human sexuality and the psychological motivations behind sexual behavior. This quiz covers key concepts related to genetic, hormonal, and sociocultural influences on sexuality. Dive into the research findings and understand the complexities of sexual identity and behavior.