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A Mind Fit for Mating. G.F. Miller The Mating Mind, Ch 4 (2000). Main Thesis. Human mental abilities shaped by sexual selection not natural selection Not necessarily optimal or rational. Sexual Selection. Goal - choose mate with best genes for offspring Feedback loops Runaway selection
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A Mind Fit for Mating G.F. Miller The Mating Mind, Ch 4 (2000)
Main Thesis • Human mental abilities shaped by sexual selection • not natural selection • Not necessarily optimal or rational
Sexual Selection • Goal - choose mate with best genes for offspring • Feedback loops • Runaway selection • Fitness indicators • Produces traits not optimal for survival
Runaway Selection • Arbitrary preferences self-reinforce • Target sex must develop trait • Selecting sex need offspring with trait • Produces marked dimorphisms
Fitness Indicators • Traits with strong correlation to overall fitness • Draw on large fraction of genome • Exogenous pressure for preference • Leads to exaggerated manifestation • Human brain • Affected by 50% of genes • Disproportionate energy use, x10-30 • Rapid tripling in size
Heritability of Fitness • Mate selection only useful with meaningful genetic variation • Absent in evolutionary equilibrium • But mutations, shifts in environment
Reliable Indicators • Selective pressure to fake • Only useful if • Direct indicator of fitness • Incur cost • Handicap principle • Wasting resources is reliable indicator of fitness
Mental Traits as Fitness Indicators • Traits not shared with other primates • Music, humor, creativity • (excess) language, altruism • Characteristic of sexual, not natural, adaptations • Large individual differences, non-modular, heritable, high costs, complex