1. Chapter 7
Male Sex Drive

2. 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

3. 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

4. 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

5. 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

6. 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

7. 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

8. 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

9. 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

11. 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

12. 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

13. 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)

14. Item Long Short p
IQ < .05
Emotional Stability < .05
Honesty < .05
Wealth ns
Health < .05
Kind < .05
Weight < .05
Religion < .05
Race < .05
Attractive < .05
Height < .05
Family ns

15. 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

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

17. 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

18. Adaptation

19. 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

20. 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

21. 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?

22. 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