1. Sexual Behavior

2. Sex Research History  Kinsey  Masters & Johnson  Kinsey  Masters & Johnson

3.  Most influential modern sexuality researcher  Atheoretical in the beginning because data on sexuality was lacking  He and 3 colleagues interviewed 18,000 subjects to obtain sexual life histories  1947, established the Institute for Sex Research  Most influential modern sexuality researcher  Atheoretical in the beginning because data on sexuality was lacking  He and 3 colleagues interviewed 18,000 subjects to obtain sexual life histories  1947, established the Institute for Sex Research Kinsey: Large Scale Sexuality Research Begins in the U.S.

4. The Kinsey Reports  Found many “unacceptable” activities to be widely practiced

5. Masters & Johnson and Scientific Sex Research

6. Masters & Johnson’s Sexual Response Cycle  4 Phase Sexual response cycle –Excitement phase: erection, lubrication, muscular tension, ^ heart rate, sex flush –Plateau phase: advanced state of arousal, orgasmic platform builds, sex skin appears –Orgasmic phase: 3-15 contractions, rush, warmth, explosion, release –Resolution phase: return to prearoused state, men have refractory period unresponsive to stimulation, women may be rearoused to multiple orgasm  4 Phase Sexual response cycle –Excitement phase: erection, lubrication, muscular tension, ^ heart rate, sex flush –Plateau phase: advanced state of arousal, orgasmic platform builds, sex skin appears –Orgasmic phase: 3-15 contractions, rush, warmth, explosion, release –Resolution phase: return to prearoused state, men have refractory period unresponsive to stimulation, women may be rearoused to multiple orgasm

7. Female Sexual Response Cycle

8. Male Sexual Response Cycle

9. Sexual Dysfunctions  Erectile dysfunction (impotence) is most often caused by physical problems such as blood vessel disease  Premature ejaculation may result from anxiety or oversensitivity  Hypoactive sexual desire occurs in both sexes and has physical and psychological causes  Vaginismus is a female disorder in which the lower portion of the vagina contracts involuntarily at anticipation of penetration. It has physiological and psychological causes  Erectile dysfunction (impotence) is most often caused by physical problems such as blood vessel disease  Premature ejaculation may result from anxiety or oversensitivity  Hypoactive sexual desire occurs in both sexes and has physical and psychological causes  Vaginismus is a female disorder in which the lower portion of the vagina contracts involuntarily at anticipation of penetration. It has physiological and psychological causes

10. HomosexualityHomosexuality

11. Homosexuality: Some Useful Distinctions 1. homosexual orientation 2. homoerotic behavior 3. male and female same-sex sexual orientation 4. individual differences within these broad categories 1. homosexual orientation 2. homoerotic behavior 3. male and female same-sex sexual orientation 4. individual differences within these broad categories

12. Primary Sexual Orientation  Males: 96 – 98% heterosexual 2 – 4% homosexual 2 – 4% homosexual  Females: 98 – 99% heterosexual 1 – 2% lesbian 1 – 2% lesbian  Males: 96 – 98% heterosexual 2 – 4% homosexual 2 – 4% homosexual  Females: 98 – 99% heterosexual 1 – 2% lesbian 1 – 2% lesbian

13. Male and Female Mating Strategies  Do males and females differ in their mate preferences and mating strategies?

14. Seeking sex with strangers in Florida

16. AnisogamyAnisogamy  The sex with the larger gamete is the female, by definition  Females begin with the bigger investment in the offspring  Often, especially in mammals, females also continue with greater parental investment after the offspring is born  The sex with the larger gamete is the female, by definition  Females begin with the bigger investment in the offspring  Often, especially in mammals, females also continue with greater parental investment after the offspring is born

17.   If one sex has great parental investment per offspring: - selection for parental effort - choosy about mating   If one sex has great parental investment per offspring: - selection for parental effort - choosy about mating AnisogamyAnisogamy

18. Parental Investment and Sexual Selection  A. high investing sex as a limited resource

19.  B. competition among low investing sex

20.  C. choosiness among high investing sex

21. The sex with low parental investment per offspring   selection for mating effort   less choosy about mating The sex with low parental investment per offspring   selection for mating effort   less choosy about mating

22. Men’s Reproductive Success…  …is only limited by the number of fertile females they have intercourse with

23. Male Sexual Psychology

24. Testis (and penis) Size

25. Testicle Size in Primates  Sperm competition can be inferred in groups with multiple males, who also have larger relative testicles

26. Sperm Motility  The midpiece of the sperm determines swimming speed and power  In species with more promiscuous mating strategies, the midpiece is larger  Sperm competition  The midpiece of the sperm determines swimming speed and power  In species with more promiscuous mating strategies, the midpiece is larger  Sperm competition

27. Sperm Competition

28. The Coolidge Effect

29. Ideal Number of Sex Partners Desired

30. Likelihood of Intercourse after Various Time Intervals

31. Female Sexual Psychology

32. Women’s reproductive success…  …is not helped by having multiple sexual partners

33. Male and Female Mating Strategies

34. Location of 37 Cultures in the International Mate Selection Project

35. Mating Preferences Preferences that are similar among the two sexes:  Mutual attraction-Love  Exciting personality  Healthy  Pleasing disposition  Kindness & understanding  Education & Intelligence  Sociable  Refinement-Neatness  Wants children  Easy going  Creative & artistic Preferences that are similar among the two sexes:  Mutual attraction-Love  Exciting personality  Healthy  Pleasing disposition  Kindness & understanding  Education & Intelligence  Sociable  Refinement-Neatness  Wants children  Easy going  Creative & artistic

36. What do men want? (that women don’t care as much about)  Attractiveness –Youth –Clear skin –Waist to hip ratio –Breasts  Attractiveness –Youth –Clear skin –Waist to hip ratio –Breasts

37. What do women want? (that men don’t care as much about)  Resources/good financial prospects –Willingness to invest in her and their future children –Education –Status –Career –Ambition  Resources/good financial prospects –Willingness to invest in her and their future children –Education –Status –Career –Ambition

38. Good Financial Prospects

40. Looks vs. Money

41. Age preferences and marital patterns: men do marry younger women