Understanding Female Sex Drive and Evolutionary Influences

1. Baumeister & TiceChapter 5 Female Sex Drive

2. Sex Drive • Motives, desire • Women < men? • Capacity • Women can have multiple Os & partners, sex after O • Enjoyment • Little difference

3. Thinking Arousal Urge strength # partners Even among dating/married Sex initiation Attitudes M more positive Same sex f Gay couples > lesbian Masturbation Pornography Fantasy Evidence of Weaker Sex Drive

4. Ellis & Symons (1990) Yes No Fantasize > 1,000 people: Male 32% 68% Female 8% 92% Fantasy includes explicit sex: Male: 48% Female 17% Fantasy focuses on: Visual Feelings Male: 81% 19% Female 43% 57%

5. Clark & Hatfield (1989) • Sexual receptivity gender difference? • Study 1 (1978) & Study 2 (1982) • 5 college women, 4 college men were Es • Average attractiveness • Ps = 48 men, 48 women • Florida State University

6. Clark & Hatfield (1989) • Procedure • E approached attractive opposite sex stranger & said • ‘I have been noticing you around campus. I find you to be very attractive. Would you go to bed with me tonight?’ • Recorded Yes or No

7. Study 1 (1978) Yes Male 75% Female 0% Study 2 (1982) Yes Male 69% Female 0% Clark & Hatfield (1989)

8. Why a Weaker Sex Drive? • Socio-Biological explanations • Evolution: Sex is biological destiny • Alpha male for limited time • Higher sex drive ~ more reproduction • Females no advantage for high sex drive • 1 pregnancy/year • Controlled via hormones like testosterone

9. Why a Weaker Sex Drive? • Cultural explanations: Sex is learned • Cultural scripts and norms • Gender appropriate behavior rewarded • Gender inappropriate behavior punished • Learning theory: Behavior producing reward will occur more frequently in future • Behave sexually in ways that maximize rewards and minimize punishment • Culturally and historically relative (e.g., 1970s)

10. Fantasy Content • Active v. passive • Men active doers, women passive recipients • Explicit v. emotional imagery • Men explicit, women emotional, narrative • Multiple partner fantasy • More common for men • Dominance fantasy • More common for men

11. Fantasy Content • Submission fantasy: More common for women • Sexual power (of woman) explanation • She is so irresistible man can not control his lust • Guilt explanation • Not to blame for sex • Social conditioning explanation • Societal eroticization of female submission • Sexual abuse explanation • Associated dominance/submission w/ arousal

12. Why a Weaker Sex Drive? • Social exchange theory (SET) • Women exchange sex for resources from men • Motivated to keep ‘price’ for sex as high as possible • Lower sex drive makes sex scarce & valuable • Scarcity theory: Rare things are considered valuable • Increases female negotiating position • She has something He wants • Maximizes ‘price’

13. Group Activity III: Sex Drive • Groups of 4-5 (mixed gender) address Q • Write down group Rs • Summarize for class • Please turn in at end of class

14. Group Activity III: Sex Drive • Define sex drive • Describe (at least) 2 sources of evidence for the gender difference in sex drive • Is it a problem when sexual partners differ on sex drive? Why/why not?

15. Female Sex Drive • Picture of weak sex drive accurate? • Implies an antipathy towards sex • Not important, meaningful in woman’s life • Really no adaptive advantage for females? • Females may be more active in obtaining, controlling & regulating sex than generally acknowledged

16. Sperm Wars (Baker, 1996) • Emerging view of evolutionary biologists • Sexuality programmed by evolutionary forces • Still impacts sexuality today • Bodies, not consciousness in control • Bodies use brains to regulate sexuality • Hormones, moods, arousal, receptivity • Programming caused by sperm warfare • Sperm from > 1 male competing for fertilization • 4%, since 1900 all have ancestor that won!

17. Sperm Wars • Female reproductive strategies/sexuality evolved to promote sperm warfare* • Obtain healthiest sperm/genes • Male reproductive strategies/sexuality evolved to fight/prevent sperm warfare • Best chance of fertilizing egg, passing genes on, & avoiding cuckoldry

18. Sperm Wars • Paints a picture of females as in control of their sexuality (even if they don’t realize it) • When they conceive, how often & with whom • Strategies to control fertility = modern day sexuality (for males & females) • Routine sex • Cervical filter • Masturbation & orgasms • Infidelity

19. Females & Routine Sex • Not for procreation • Average couple will have sex 2,000-3,000 times in their lifetime • Vast majority have < 7-8 kids • 500 episodes of sex/kid • Sex drive does not cease post-fertile years

20. Females & Routine Sex • Developed as part of reproductive strategy • Confuse males about fertility • Hidden & inconsistent menstrual cycle • Control when & with whom they conceive • Routine sex most common after ovulation • Pill produces similar effects implicating hormones

21. Cervical Filter (CF) • Ejaculate comes to rest in a coagulating seminal pool at floor of vagina • Cervix expands, dips into vagina during intercourse & following insemination rests on the vaginal floor in seminal pool • Cervical mucus contains channels through which sperm travel to uterus & egg

23. Cervical Filter (CF) • Nature of mucus changes • # channels, channel size, flow rate, blockages • Infertile phase few channels & > blockages • Hinders passage of sperm • Fertile phase more, larger, clearer channels • Makes sperm passage easier • Cervix acts as a filter for sperm

24. Cervical Filter (CF) • Ability to change strength of CF critical to reproductive control/success • Flow-back: In ~15 minutes seminal pool decoagulates & is ejected out vagina • Average CF = 50% of sperm • Strong CF ejects ~90% • Weak CF ejects ~10% • Female body controls how many sperm are kept

25. Masturbation & Orgasm • Great range of female orgasm • 80% masturbate (Average = 1/week: Class M = 1.97) • Stimulate clitoris w/ fingers (to orgasm) • Not designed for intercourse (~10% have O) • Class: M = 61% F = 39% have O during intercourse • Biologically developed as self-stimulation (fertility) • Orgasms critical for reproductive success • Evolved to have a reproductive function

26. Orgasm & Cervical Filter • Orgasm: Cervix gapes & dips into vagina • Increases mucus flow from cervix to vagina • Ejects cervical debris (sperm which block channels) • Increases acidity of mucus (killing sperm) • Orgasm during masturbation increases CF strength

27. Orgasm during intercourse weakens CF Only after insemination (< 1 hour) Cervix widens opening new channels Cervix dips up & down into seminal pool Vaginal contractions suck semen into channels O during intercourse 50% - 90% sperm retained No O during intercourse 0%-50% sperm retained Orgasm & Cervical Filter

28. Orgasm & Cervical Filter • Female body prepares for next intercourse • Orgasm before not during w/ routine partner • Strengthen filer • No orgasm before but during w/ infidelity • Weakens filter • Females control w/ whom she conceives

29. Orgasm & Cervical Filter • Masturbation more likely before routine sex than before infidelity • Nocturnal orgasms more likely before routine sex than before infidelity • 22% of time orgasms during sex w/ routine partner • 33% of time orgasms during sex w/ lover

30. Female Infidelity • Females want (evolutionarily speaking) • 1. Long-term mate and provider/care-giver • 2. Short-term mate to supply good genes for conception

31. Infidelity • Characteristics associated w/ these differ • 1. Long-term: Stable, nurturing, loyal, resourceful, ambitious, status, wealth • 2. Short-term: Healthy, symmetrical features, broad shoulders, smart, small waist • Features most attractive changes w/ cycle • Scent of symmetrical, masculine men more attractive during fertile phase of cycle • Only for short-term mates

32. Item Long Shortp IQ 3.20 5.33 < .05 Emotional Stability 4.30 6.33 < .05 Honesty 1.92 6.08 < .05 Wealth 8.73 8.28 ns Health 9.92 5.36 < .05 Kind 3.20 4.75 < .05 Weight 8.28 4.67 < .05 Religion 8.23 9.88 < .05 Race 8.74 7.77 ns Attractive 5.03 1.82 < .05 Height 8.52 5.83 < .05 Family 8.78 10.87 < .05

33. Infidelity • Females often compromise • Marry 1 & have affair with 2 • 10% of children not sired by rearing father • Even higher among low-status males • Adaptive for females to be promiscuous/cheat • Promotes sperm warfare • Regulate their routine sex & masturbation routines to maximize chance of conception w/ lover rather than partner

34. Sperm Wars Conclusion • Sexuality programmed by sperm wars • Sexuality among females evolved to promote sperm warfare • Females control reproduction • With whom & when conception occurs