Male Long-Term Mating Strategies The Problems of Paternity

Foundation of Male Mating Minimum investment  Considerably lower in human men than in women  In ancestral environment, men had relatively little to lose by copulating with a “less fit” partner  Male reproductive variance (e.g., Ismail the Bloodthirsty)

Why Invest At All? (1) If there is little cost to reckless mating, then why adopt a long-term strategy?  Benefits to offspring (survival, future reproductive success)  Paternity certainty  Non-committing men would have suffered in mating market

Parental effort  Proportion of total reproductive effort invested in rearing and defense of offspring Mating effort  Proportion of total reproductive effort invested in the acquisition & maintenance of sexual mates Parental and mating effort often conflict Why Invest At All? (2)

Reproductive Value While fertility in men may decrease over the lifespan, it does so only slightly Women, however, have a much smaller reproductive window Men should be attuned to signals of a woman’s reproductive value  Number of children a person of a certain age and sex is likely to have in the future

Cues of Youth & Health Men prefer  Slightly younger women than themselves  Particularly, women in peak reproductive age  Healthy women Tradeoff between fecundity and fertility for long-term investors

Beauty Standards May be both physical and behavioural People of all ages (including infants) are capable of discriminating beauty standards There is cross-cultural agreement on many standards (though variation as well)

Symmetry and Averageness Fluctuating asymmetry is a marker of developmental stability  Low FA is seen as attractive  Increases with age  May be associated with psychological characteristics as well Averageness is also preferred in mates

Waist-to-Hip Ratios (1) Proportion of body fat is a variable beauty standard across cultures At puberty, body fat distribution differs between boys & girls  In girls, fat is distributed around upper thighs, buttocks, and hips  This decreases the waist-to-hip ratio

Male range: Female range: WHR is negatively correlated with  Fertility  Health Has been demonstrated cross-culturally, though there is disagreement Waist-to-Hip Ratios (2)

Two Objections re: Ovulation Buss may have mislead you on two points 1. There is no evidence that concealed ovulation was selected for; rather, “advertised” ovulation probably evolved 2. There is no evidence that men can detect women in their ovulatory phase

Paternity Uncertainty Due to paternity uncertainty, men prefer  Premarital chastity  Sexual fidelity Mother & her family put great emphasis on reassuring father of his paternal status Men care more about the resemblance of offspring than women

Context Effects Man’s status & prestige  High standards  Greater age discrepancies Pin-ups & Centrefolds  Appear to have an effect of raising standards  Do not appear to elicit misogyny or violence, per se

The Wrap-Up Minimum investment Male parental investment Parental effort & mating effort Cues of youth & health  Symmetry, averageness, WHR Concealed vs. advertised ovulation Paternity uncertainty

Things to Come Short-term mating  Costs & benefits  Adaptive problems  Evidence