Relationships - Evolutionary explanations

Darwin outlined intersexual and intrasexual selection; 

- intersexual selection is about mate competition, to ensure genes are passed on 

- intrasexual selection is about mate selection, to ensure children have desirable genes 

He explored partner preference by researching 10,000 people from 37 different cultures. He found some universal preferences ; 

- men valued physical attractiveness highly (indication of health and fertility) 

- women valued resources highly (to take care of them and potential children) 

- both sexes valued intelligence, kindness and dependability.

Men tend to be less fussy then women when it comes to short term mating preferences. This can be explained by parental investment - a man can impregnate lots of women to ensure his genes are passed on. Yet women only produce one egg a month so have a much more limited chance of having lots of children. They'll be pregnant for nine month, and have to invest years of intense childcare. Therefore it makes sense women tend to be more fussy. 

They had male and female confederates approach strangers on a university campus and told them to as one of three questions to them; 

( Male % vs Female % that agreed)

- Would you go on a date with me? (M : 50% F : 50%) 

- Would you go back to my apartment with me? (M : 69% F : 6%)

- Would you have sex with me? (M : 75% F : 0%) 

This study demonstrates the differences between males and females in short term mating. 

Neither sex want to waste their resources when it comes to raising children. By choosing a mate who is attractive it means that offspring are more likely to be healthy and pass those genes on themselves. Whilst men might be less fussy when it comes to short term mating, they will be more selective about long term. 

- Men often favour shorted women, women favour taller men 

Despite the fact that you cannot tell when a woman is ovulating (and fertile), Miller observed that lap dancers in a US club generally earned more tips when they were ovulating. 

- research has shown women tend to dance more provactively when theyare ovulating. 

Penton Voak et al found that womens mate choice varies during their menstrual cycle.

• - Women prefer men with a more feminised male face and rate it more attractively in regards to long term mating preference due to its association with kindness, care and co-operation
• - Yet when they are ovulating they may chose a more masculine face due to its healthy and macho connotations

• Does not explain why women cheat or are promiscuous. It makes sense for a woman to find someone who will protect them, yet mate with soemone who is more attractive and healthy to ensure their offspring are healthy 
• Male preference for younger women is not universal ; Kenrick et al found teenage boys are often attracted to women five years older than them
• Cannot explain homosexual relationships, or relationships were reproduction is not a main priority

• Determinist - biology choses, not us meaning no personal choice
• Reductionist - Complex behaviour should not be reduced to reproduction 
• Speculation - no real genetic basis 
• Underplaying culture - women no longer depend on men for money etc
• Sexist - reinforces male sexism

Discuss evolutionary explanations for partner preferences