PSYCH 3F03 Lecture Notes - Lecture 5: Menarche, Pubarche, Menopause
13 Sep 2018
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Document Summary
Robert trivers (1943-present: reciprocalaltruism(1971):mutuallybene cialrela onshipsbetweennon- kin 2) parentalinvestmenttheory(1972):sexdi erencesinma ngbehaviour 3) parent-o springcon ict(1974):onlyshare50%ofgenes(other50%=con ict) Problem: inclusive tness only explains sociality among rela ves. If r=0, trait shouldn"t evolve but we see it (especially humans) Costs of social living: compe on (resources/mate), disease transmission. Bene ts of social living: coopera ve defense against rival groups/predators, social learning/wisdom of culture, comple ng projects. Solu on: reciprocity you help me = i"ll help you. Coopera on promotes minimal loss (= reproduc ve success) parental. Investment theory sex di erences in reproduc ve rate. Women: age of menarche, menopause, gesta on, lacta on. Men: age of pubarche, access to fer le women: less factors = more poten al o spring opera onal sex ra os. Number of males/females available to mate: more males = polygyny o more females = polyandry o equal numbers = monogamy. Sex with more variance in reproduc ve success = more compe on for mates.
