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)
Men and women designed for lifetime deep, monogamous love Female fidelity is good for males, so females developed fidelity
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
amount of resources, time, energy, etc, male parents spend on raising their children humans exhibit high MPI relative to other species
Moved from forests into savanna Became smarter and more upright › Narrow pelvis Clinging baby + mother gathering food › helpless tiger bait
Females reproduce once in a long time Females should be more selective about who they mate Want high ongoing investment
› 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
As much sex as they can get away with Attracted to fertile-looking females High MPI species, so s omewhat selective
measured with electrodes on skin › Sexual infidelity – Men more upset › Emotional infidelity – women more upset
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.”
Men and women tend to be, respectively, exploiter and exploitee Men have more to gain from deserting family
Selection favors males who can deceive about future devotion › Self-deception effective too Selection favors females who can spot deception
“resource extraction” hypothesis “seeds of confusion” hypothesis “best of both worlds” hypothesis Women are more sexually active around ovulation.
Successful male infidelity is advantageous for males And if female infidelity was not long- standing… Average testes weight to average male body weight
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
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”
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
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
monogamy is not our nature Might be better off without this strict monogamy