The PIT provides a plausible explanation for the differences in sexual reproductive behaviour between genders. It’s realistic as it helps us understand that women will look for good genes and men who are commited, as well as those who have money as this will help raise their child, i.e. high PT. Men will look for women with attractive young women with neotenous facial features as this shows signs of health and of them being fertile. These predictions support the finding by Buss and Scmitt (1993).
Alongside to this, it helps us understand differences in jealousy. It allows us to comprehend why men are more concerned about sexual infidelity whereas women are more concerned about emotional infidelity. If a man’s partner sleeps with someone else they raise the risk of raising someone else’s child, so men are under the pressure to protect themselves against cuckoldry. This is devastating for them as they are wasting their resources for someone that doesn’t even share their genes.
Women don’t have this problem as they know it’s their child. However, if a man falls in love with someone else, then the resources will be shared amongst them. This will cause major repercussions for the women as they won’t receive all the attention they did before, the money will be shared so their lifestyle will have to change and the child will also get less attention from the father.
It doesn’t account for individual differences because not all mating behaviour is about long term relationships which results in children. There are some individuals that have sex for pleasure but will never have children as they are focused on their careers or other aspects of their life. There is evidence that there are an increasing number of women having one night stands and short term relationships. Pérusse 1993 suggest that this increasing number, especially in western societies, is due to contraception. In wealthier countries, males and females have sex more frequently, but not for procreation and socially enforced monogamy, just for pleasure. Furthermore, Sternglanz and Nash in 1999 found that one night stands don’t tend to result in pregnancy which could in turn cause more women to be willing to have sex with random men.
Culture also has a big role in shaping reproductive behaviour. For example, it is socially acceptable for men to be promiscuous. Those men who sleep with many women will be seen as a ‘legend’, or a role model for other men, because it’s every man’s dream to sleep with a large number of women. However, if women are promiscuous and sleep with more than a handful of people they will be shunned upon. If we look at female chimpanzees, they are very promiscuous, so males have to compete a lot.
They have evolved to have large testicles to provide sufficient sperm. Gorillas on the other hand have small testicles compared to their body size because females are monogamous so there is little competition. Human males have medium sized testicles by primate standards. Baker and Bellis (1995) suggested that the norm for ancestral males was to compete, so females must have been promiscuous and had various partners. Therefore, due to these findings it wasn’t frown upon for women to be promiscuous as it is nowadays.
Lastly we have to take into considerations free will and determinism. If sexual selection, human reproductive behaviour and the relationships it involves are truly due to evolutionary factors, then all relationships would be highly predictable. However, as time has passed, contraception has become more easily available, so some couples chose to have sex but not to conceive a child. In some cases some people don’t even want to have children. Furthermore, there has been an increase in homosexual relationships. This implies that we have more control over our behaviour than the evolutionary theory says we do.