Chapter 7 Male Sex Drive

Sperm Wars (Baker, 1996) Male sexuality evolved to prevent/fight sperm warfare Maximize chance of fertilizing egg, passing genes on, & avoiding cuckoldry Penis anatomy, thrusting & rapid orgasm Routine sex & topping off Masturbation Infidelity & jealousy

Penis Anatomy & Thrusting Shape/thrusting cleans out other sperm Suction Larger the greater the suction Rapid orgasm Maximized insemination Animals: Rapid insemination after infidelity Why males find pornography so arousing

Penis Anatomy & Thrusting Reproductive disadvantage to male for female to have orgasm before sex Increases strength of cervical filter Males biologically destined to ‘rush’ w/o foreplay, climax rapidly

Nature of Sperm Average ejaculate contains 500 million sperm 3 primary types: Killers (fast, youngest, poison head) Seek out and kill other men’s sperm Blockers (slow, old) Block other men’s sperm Egg-getters > 99% of sperm in ejaculate are killers or blockers < 1% of sperm are egg-getters

Nature of Sperm Sperm live 5 days in female 2 days to peak fertility Egg dies w/in 1 day of release Male must inseminate 3-4 days < ovulation Best chance of conception if 2-3 days before Sufficient killers & blockers to win sperm war

Routine Sex & Topping Off Hidden ovulation: Males consistently inseminate partner Higher sex drive Males adjust #, type sperm to keep healthy, fresh sperm in cervix (top off) Delay since last sex (chance of foreign sperm?) 5 days: 400 million 3 days: 200 million 3 hours: 30 million

Routine Sex & Topping Off Critical to winning sperm wars Keep killer, blocker sperm population high For 3 days post-intercourse Aging of sperm in testes matches loss of blockers in cervix Inject exactly the right amount of blockers to top off population

Routine Sex & Topping Off Columns of sperm in epitidymis Closest to testicles youngest Farthest away oldest (blockers, killers) Adjust sperm via muscular contractions, number of spurts

Masturbation 98% males masturbate (3/wk, Class M = 4.89) Many mammals also Shedding sperm Testes produce 300 million sperm/day Shed 5 million/hour since last ejaculate First to be ejaculated oldest

Masturbation Male body times urge to maximize chance of winning sperm wars Purpose is to tailor ejaculate for next intercourse Adjusting type, number of sperm Shedding old, slower sperm Best 2 days < insemination Many young killers & blockers Can be further adjusted depending on infidelity risk

Infidelity & Jealousy Sexually jealous/possessive of partners Most jealous/in control less chance of cuckoldry More HIS genes passed on Male sexuality evolved w/ desire for numerous, fertile partners (even strangers)

Item Long Short p IQ 3.28 7.07 < .05 Emotional Stability 4.10 6.34 < .05 Honesty 3.17 6.07 < .05 Wealth 8.90 8.14 ns Health 6.48 4.10 < .05 Kind 3.93 6.10 < .05 Weight 5.52 2.69 < .05 Religion 7.48 4.19 < .05 Race 7.38 6.24 < .05 Attractive 3.00 1.24 < .05 Height 8.28 4.93 < .05 Family 9.83 10.17 ns

Male Sex Drive Men want lots of sex w/ lots of partners Relationships are better but still... Men want 50% more sex than they are having Women sex desire = actual amount

Sexual Starvation Chronic sexual frustration inevitable for most men High status males may be able to achieve satisfaction (Brad Pitt, Bill Gates) Temporary

Adaptation Habituate to any S intensity Money, Sports, Drugs Taste, touch Incrementally decrease R Incrementally increase desired S Money, Sports, Drugs Lottery winners initial euphoria fades Jordan & multiple championships Pot gateway drug

Adaptation

Sexual Starvation Sex Made worse by social comparison (Festinger) Virgins just want 1 Then after 1 you just want 2-3 and so on Made worse by social comparison (Festinger) Compare w/ others to evaluate ourselves Men may lie or be inaccurate Volunteers different than non-volunteers Media distorts sexual experiences of males

Sexual Starvation Males will never be sexually satisfied because no matter how much sex they have they will eventually adapt & want more Doomed to be perpetually frustrated Sexual boredom (males > females) More masturbation & risky sex (prostitutes, unprotected sex, cheating) Desire for big pay-off increases risk taking

Reaction Paper III: Sexual Starvation What is your reaction to the idea that men are fatally doomed to experience chronic sexual frustration, not getting enough sex even when married? How do you think this will impact the way you deal w/ relationships in the future?

Conclusion Male sex drive complicated & may have evolved to prevent/fight sperm warfare One consequence is high sex drive and perpetual sexual starvation via habituation