The theory of sexual selection -1
Darwin came up with his theory of sexual selection, describing two processes through which it took place – intrasexual selection, where members of one sex compete with one another for access to members of the other sex. The winners are able to mate, pass on their genes, which is then passed on to the next generation. Intersexual selection involves the preferences of one sec for members of the opposite sex that possess certain qualities. For example, if females prefer males that are taller, over time there would be an increase in tall males.
The theory of sexual selection -2
Evolutionary psychologists propose that human sexual behaviour is influenced by the sexual selection theory. Both men and women have evolved sexual preferences which will improve their chances of successful reproduction. Women often find good financial prospects desirable, this often translates into a desire for men with resources or qualities linked to resource acquisition, such as ambition. However men placed more importance on physical attractiveness. Research has consistently shown that physical appearance provides a wealth of cues to a woman’s health and hence her fertility and reproduce value.
The theory of sexual selection -3
Short term mating preferences vary across different humans – according to the parental investment theory, men evolved a greater desire for casual sex and ideally seek sex earlier in a relationship. However Female behaviour would not be subjected to the same evolutionary pleasures. In long term mating, both sexes typically invest heavily in offspring. As a consequence of this, sexual selection should favour high levels of choosiness in both sexes. Poor choice in long term mates can be disastrous as they have wasted valuable resources, women are often very particular about their mate as they have an bigger biological investment.
The theory of sexual selection -4
There are several strengths and limitations to this study, one strength is that the theory of sexual selection in human reproductive behaviour has given us a deeper understanding of how genes can influence human sexual preferences. The theory shows us that we are not a construct of our environment but some aspects of human behaviour are fixed due to our innate biological make up which has evolved over millions of years.
The theory of sexual selection -5
However sexual selection theory on human reproductive behaviour has been criticised for being unscientific. The evolutionary explanation is supported mainly be post hoc (after the even had happened) evidence. This makes it difficult to falsify or confirm it is true because there is no empirical evidence showing it to be wrong. For example, claiming that male promiscuity has evolved in order to maximise reproductive success, one can equally claim that men who are faithful to their wives, can also have a survival value because two parents care improve the likelihood of the child surviving.
The theory of sexual selection - 6
In addition to this Thornhill and Palmer argue that the theory of sexual selection of human behaviour raises ethical issues, they argue that the sexual selection theory can be used to explain sexual deviant behaviour such as ****, as this may have had a survival value in our ancestral past. Less desirable or low status males are less likely to gain access to a potential female partner; so males forcing sex on females could be seen as a biological strategy used to increase the chances of reproductive success.
The theory of sexual selection -7
Criticism for sexual selection theory comes from the idea that it doesn’t explain why some women choose to be promiscuous or unfaithful towards their partner. This idea refutes sexual selection theory which suggests that women pursue a single male that not only has good genes but is willing to invest in offspring. Numerous research shows extra marital affairs are fairly high in both sexes. Women’s behaviour may have evolved if they are unable to find ‘good genes’ so to compensate for this, women may have developed certain behaviours. This includes sexual infidelity where the female secures emotional investment and financial investments whilst gaining good genes from another partner, this is known as cuckoldry and results in their financially supportive partner raising a child that is not biologically there.
The theory of sexual selection - 8
The sexual selection theory holds the view that human sexual preferences are at the mercy of our adaptive past in the sense that behaviour is genetically determined by our evolutionary history. It does not take into account that human behaviour is capable of consciousness, the thought that gives humans the free will to male choices. For example, in Buss’s cross cultural study, both men and women ranked qualities such as ‘kind’ and ‘intelligence’ as being more important that physical attractiveness or male financial resources which seems to go against the evolutionary theory.