Discuss the relationship between sexual selection and human reproductive behaviour in relation to the evolutionary theory

Differences exist between the male and female reproductive behaviours and according to evolutionary theory, these are due to different selective pressures. Characteristics that indicate reproductive success are selected for our mates. Dunbar and Waynforth found men valued physical attractiveness and youth in females, supporting the concept that males seek fertility and reproductive success in females. Females on the other hand value financial security in males to ensure they can support and provide for a family. These findings have cross-cultural strengths as Buss collected data from 33 countries. This suggests that these traits are genetically determined with an evolutionary value rather than a nurtured preference. However, Bereczkel et al found that women actually want males that are more family orientated therefore are less concerned about resources therefore contradicting this theory of choosiness and human reproductive behaviour. In addition, it has been argued that men prefer a youthful female because of social power. Younger women are easier to control and are therefore preferable as mates. But Kenrick et al found that that teenage males are attracted to females who were 5 years older. This therefore goes against the evolutionary explanation. Buss’s study also may not provide strong support for the relationship between sexual selection and human reproductive behaviour because answers they gained may be what they preferred but not what they had because they may have compromised. However, another study conducted by Buss of actual married couples supported the original results that men do marry women that are younger than them, thus increasing the validity of this explanation. According to Darwin selection processes shape are reproductive behaviours. Intersexual selection (competition between genders) is dominant within females, whilst Intrasexual selection (completion within the same gender) is more dominant in males. Therefore men’s best mating strategy is to have many sexual partners to ensure reproductive success as they have lots of small mobile sperm which they produce over a long period of time. Whereas women benefit from nurturing selected offspring as they produce, fewer larger eggs over a short time. Penton-Voak et al supported the idea that females use intersexual selection. They found that the female mate preference varied depending on menstrual cycle stages. During high contraceptive risk phase of the cycle, females preferred masculinised faces and short term sexual relationships. In contrast outside this stage, they focus on long-term relationships. This supports that our sexual selection is underpinned by reproductive behaviours and evolutionary origin. This is because short term mating is linked with childbearing and therefore key preferences could be strong genes and attractiveness emphasised by masculine measures, whereas long term the mores important traits are competence in raising a child and resources so softer features associated with support and nurturing. Miller et al’s research does suggest that despite gender stereotypes, women are biologically programmed from reproductive opportunities. He found that lap dancing females who were in the most fertile stage of the cycle gained more tips. Suggesting males are most attracted to females who are in the most fertile point. However, clear gender difference in the general willingness to engage in uncommitted sex. Clark and Hatfield found 57% of males would accept an offer for a one night stand with a stranger compared to 0 females. This suggests males have evolved a motivation for casual sex. The implications of the research were supported by Buss et al who found that women want less sexual partners then males. This approach suffers from a strong gender bias as males are accused of wanting to spread their seeds due to evolutionary reasons but this behaviour would not be learned without willing females. As a result, the role of females in this process is under evaluated. Grilling and Buss suggested that females could also profit from short term mating such as a way to leave a poor relationship or producing more genetically diverse offspring. Therefore, short term mating suffers from gender bias, particularly saying that women cannot be sexually promiscuous and that it is a male characteristic, which is isn’t in modern society. Overall, these explanations can be criticised for being reductionistic as they cannot explain homosexual relationships and the drive for these relationships, as there are no reproductive advantages. Reproductive behaviours have changed dramatically over the last century with non-heterosexual relationships, widespread of contraception and choosing to not have children. This implies we have more free will over our behaviour than implied by the evolutionary approach. The approach also supports gender stereotyping with men being players which suffers from ethical implications. Therefore a more holistic approach which included psychological rationale might be more appropriate form explain homosexual relationships and provide a more balanced explanation rather than an approach that suggests we are a product of our genes.