Relationships

- Human reproductive behaviour refers to any behaviours that relate to opportunities to reproduce and thus; increase the chances of survival of our genes.

- Anisogamy is the difference between male and female sex cells. A consequence of anisogamy for mate selection is that there is no shortage of fertile males but there is a shortage of fertile females. It gives rise to two mating strategies and thus; two types of sexual selection.

-Inter-sexual selection is the preferred strategy by females - quality over quantity. Ova are more rare, and (Trivers) females make a greater investment before, during and after the offspring is born. The consequence of choosing the wrong mating partner is more serious for femlaes; therefore, they are choosier. So, the optimum mating strategy is to choose a genetically fit partner who can provide resources. 

- Inter-sexual selection - if  female has a preference for a trait, it will eventually increase in the male population as mating partners will produce sons with that trait and daughters who prefer that triat. This is the runaway hypothesis in Fisher's **** sons hypothesis.

- Intra-sexual selection is the preffered male strategy - quanitiy over quality. The winner of competition reproduces and passes on their characteristics. This causes dimorphism.There are behavioural consequences e.g.males want to protect females from competing males so they may benefit from behaving aggressively. Anisogamy states that the preferred male strategy is to mate with as many females as possible as it reuqires little energy and they lack post-coital responsibility. A behavioural consequence of this is that males prefer indicators of youth. 

- Research support for preferences. Buss carried out survey of 10,000 adults in 33 countries. Females valued resource-related characteristics and males valued reproductive capacity. This supports predictions of partner preference and because it applied across all the cultures it shows that fundamental human preferences are not primarily dependent upon cultural influences.

- Research support for inter-sexual selection. Clark and Hatfield - 75% of males said yes and all females said no.This shows that females are choosier and the male strategy is to ensure reproductive success.

- Ignores social and cultural factors. Partner preferences have been influenced due to changing social norms and cultural factors like contraception. Bereczkei argues that as more women work their preference is less resource-orientated. Thus, preferences are due to evolutioary and cultural influence - the theory doesn'y account for both which makes it limited.

- Support from waist-hip ratio. Males prefer femaly body shape that indicates fertility. The ratio of waist to hip needs to be about 0.7 to be attractive. Wide hips and narrow waist is an honest signal that the female is fertile and not pregnant.

- Support from lonely hearts research. These ads allowed men and women to describe what qualities they liked and what they found attractive. Dunbar and Waynforth Women tended to offer physical attractiveness and men offered resources.