Reproductive behaviour and evolution
•How has evolution shaped our •Sexual preferences? •Our sexual behaviours? •Our relationships? •Purpose of reproductive behaviour – to survive and pass on genetic material, to give us a reproductive advantage.
•Attracting the mate with the greatest fitness to reproduce healthy offspring. •Maximising own chances of being selected as ‘fit’
•2 types: •Intra-sexual selection – competition between members of same sex (usually males though) •Inter-sexual selection – female choice of male mate
Inter-sexual selection (which man/woman shall I ch
Men look for -
Physical appearance – young attractive women Women look for- Indicators of socioeconomic status
Buss (1989) ‘What Women Want’
•Conducted large cross-cultural study into human mating preferences. •> 10,000 people, 37 cultures •Found consistent gender differences
- Women wanted:
- Good fianicial provider
- Tall and strong
- Older men
- Symmetrical face and body
- Men wanted:
- Younger women
- Healthy and physically symmetrical
- Good waist to hip ratio (0.7)
Waynforth & Dunbar (1995) ‘Lonely Hearts’
•Content analysis of personal ads in 4 newspapers •479 male ads, 402 female ads
Men aged 40 – 49 most likely to express preference for a fertile woman
Women were twice as likely as males to advertise their physical attractiveness
»Demanded wealth in a partner 4.5 times more often than men
Campos et al (2002) ‘Choosy Old Men’
•Also studied personal ads. •As women aged, they became less demanding. •Whereas men became more so, with age.
So, what do we find attractive?
•Cartwright (2000) both men & women prefer symmetrical faces. •Symmetry equates with fitness. •Cartwright also found that women with symmetrical breasts are more fertile.
•Is there an evolutionary basis to who we find attractive? •Cunningham 1986: varied female features and found men most attracted to women with large eyes, small noses, narrow cheeks (i.e child like features). Women most attracted to men with square jaw, ridged eyebrows, small eyes, symmetrical faces. •Bruce and Young: we have a preference for symmetrical faces.
•Langlois et al 2000: •Meta-analysis of 919 studies. –Lots of agreement within cultures on what is attractive –Some disagreement between cultures –Preference for attractive faces starts in childhood and is strong by 26 months old
‘Curves in the right places’
Singh identified waist-to-hip ratio (WHR) as a universally major determinant of attractiveness.
•Used data from past 50 yrs of beauty contest winners and Playboy centrefolds. •Small waist and full hips consistent feature. •Breast size, overall body weight and physiques varied over time. •Optimum WHR = 0.7 (associated with fertility)
Miller et al (2007)
‘Ovulating lap dancers’
Most female mammals display oestrus to alert males to receptivity. •In humans, oestrus is hidden. Or is it?...
Miller et al (2007)
•Compared earnings of lap dancers menstruating naturally with those on the pill. •During non-fertile periods, both sets of dancers earned similar tips. •BUT when dancers not on the pill entered fertile phase, they earned significantly more tips than pill taking dancers.