Men and Women

1. Men and Women From Robert Wright’s The Moral Animal Presented by Charlette Lin • One can, in effect, treat the sexes as if they were different species, the opposite sex being a resource relevant to producing maximum surviving offspring. • - Robert Trivers (1972)

2. “Pair-bonding” theory • Men and women designed for lifetime deep, monogamous love • Female fidelity is good for males, so females developed fidelity

3. “Pair-bonding” theory cont. • all known human cultures have marriage (though varying types of marriage) • having a family is the norm • but 980 of 1154 human societies allow men to have more than one wife • though polygynous marriage is not the norm

4. Male Parental Investment (MPI) • amount of resources, time, energy, etc, male parents spend on raising their children • humans exhibit high MPI relative to other species

5. Why high MPI? • Moved from forests into savanna • Became smarter and more upright • Narrow pelvis • Clinging baby + mother gathering food • helpless tiger bait

6. What do women want? • Females reproduce once in a long time • Females should be more selective about who they mate • Want high ongoing investment

7. Study: Minimal intelligence of someone you’d date? • Women: average intellect • Men: average intellect • Intelligence of someone you’d have sex with? • Women: Oh, in that case, above average intellect • Men: Oh, in that case, below average intellect

8. What do men want? • As much sex as they can get away with • Attracted to fertile-looking females • High MPI species, so somewhat selective

9. Study: Emotional reactions • measured with electrodes on skin • Sexual infidelity – Men more upset • Emotional infidelity – women more upset

10. “Madonna-whore dichotomy” • two kinds of women: the kind you respect and the kind you just sleep with • “the male may actually encourage the early sex for which he will ultimately punish the woman.”

11. Exploiter and exploitee • Men and women tend to be, respectively, exploiter and exploitee • Men have more to gain from deserting family

12. Arms race • Selection favors males who can deceive about future devotion • Self-deception effective too • Selection favors females who can spot deception

13. “cryptic ovulation” hypothesis • “resource extraction” hypothesis • “seeds of confusion” hypothesis • “best of both worlds” hypothesis • Women are more sexually active around ovulation.

14. Human infidelity • Successful male infidelity is advantageous for males • And if female infidelity was not long-standing… • Average testes weight to average male body weight

15. Myth of Samoans • Margaret Mead • No needless anxieties about sex • Casual lovemaking • No ideas of exclusiveness, jealousy, or undeviating fidelity • If husband caught wife in adultery, appeased by harmless ritual

16. Myth of Samoans cont. • Derek Freeman • Upon marriage, good girls manually deflowered • If girl found with a boy and suspected to have lost her virginity, her brothers would “upbraid and sometimes beat” her • Young men who failed at the mating game sometimes “forcibly deflower” a woman and threaten to tell others unless she married him • If woman found to be non-virgin on wedding day, publically denounced “whore”

17. Developmental plasticity • Madonna or whore, cad or dad? • During childhood, assess local social environment • More attractive adolescent girl, more likely to “marry up” • Evolutionarily advantageous to be flexible

18. Disclaimer • Could think of many different hypotheses for why these sexual strategies were shaped • But cannot argue that evolutionary psychology is irrelevant to the whole discussion

19. Conclusion • monogamy is not our nature • Might be better off without this strict monogamy

20. The end Thank you!