Discuss the relationship between sexual selection and human reproductive behaviour 16 marker

Sexual selection is a key concept in evolutionary psychology that explains how certain traits increase reproductive success. Anisogamy refers to the differences between male and female sex cells, leading to different strategies: males produce many small sperm and benefit from mating widely, while females produce fewer, energy-rich eggs and must be more selective. Inter-sexual selection occurs when one sex (usually females) chooses mates based on traits that signal good genes or resources, such as strength or status. Intra-sexual selection happens when members of one sex (usually males) compete with each other for access to mates, favouring traits like aggression and dominance. These processes shape human reproductive behaviour, including mate preferences and strategies like mate guarding and courtship rituals. Evolutionary pressures have led to behaviours such as males seeking signs of fertility and females preferring resourceful or genetically fit partners.

One strength of sexual selection as an explanation of human reproductive behaviour is that it is supported by empirical research.
Clark and Hatfield (1989) found that when students of the opposite sex were approached on campus and asked for casual sex, 75% of males agreed, but 0% of females did. This supports the idea of female choosiness in mate selection, consistent with inter-sexual selection theory. It demonstrates that women are more selective due to the higher biological investment in reproduction. However, this research may lack ecological validity, as the context (a university campus and direct propositions) may not reflect real-life mating behaviours, potentially limiting the generalisability of the findings.

A limitation of the theory is that it overemphasises biology and may ignore the role of free will and environment. Sexual selection theory assumes that mate preferences and behaviours are entirely driven by genetic survival advantages. This could be considered biologically reductionist, as it overlooks important social, cultural, and personal influences on human behaviour. However, the theory is rooted in evolutionary psychology, which aims to offer ultimate explanations for behaviour, not necessarily proximate ones like social norms.

A limitation of sexual selection theory is that it may lack temporal validity. In modern societies, traditional gender roles are changing, and women are now more financially independent. This challenges the idea that women still prefer men with high resource-acquisition ability, suggesting the theory may not fully apply to current mating behaviours. Nonetheless, some mate preference patterns, such as men's preference for youth and women's for resources, are still found in cross-cultural studies, suggesting a degree of universality.

A limitation is that sexual selection theory may not be generalisable to all populations.
It primarily explains heterosexual relationships and reproductive behaviour. This limits the population validity, as it cannot fully account for non-heterosexual relationships or sexual activity not aimed at reproduction. Despite this, the theory can still be valuable in explaining common trends in reproductive strategies across human societies.