What is Sexual selection?
This is an evolutionary explanation of partner preference proposed by Charles Darwin which suggests that individuals/organisms that have certain attributes or behaviours that increase reproductive success are more likely to find a mate and pass on those advantageous attributes onto their offsprings with those advantageous attributes becoming more common in the population.
What is Anisogamy?
This refers to the differences between male and female sex cells (gametes)
Features of the male gametes- Sperm.
They are extremely small and highly mobile. They are also created continuously in vast numbers from puberty to old age and do not require a great expenditure of energy to produce
Features of female gametes-ova,
They are relatively large and static. They are produced for a limited number of years and require a high expenditure of energy to produce.
What is a consequence of anisogamy for mate selection?
A consequence of anisogamy for mate selection is that there is no shortage of fertile males but a fertile female is seen as a “rare resource”
Why is anisogamy important tho?
It is important in partner preference because it gives rise to two mating strategies: Inter-sexual selection and Intra-sexual selection.
What is Inter-sexual selection?
Inter-sexual selection is the mating strategy between the sexes when choosing a mate, but is it mostly done by females
Why are the consequences of choosing a wrong partner more serious for females than males?
Robert Trivers (1972) emphasises that females make a greater investment of time, commitment and other resources before, during and after pregnancy so the consequences of choosing a wrong partner is way more serious for the female than the male.
What is the female’s optimum mating strategy?
The female’s optimum mating strategy is to select a genetically fit partner who is able and willing to provide resources which leaves the male competing for the opportunity to mate with the fertile female.
What is the sexy sons hypothesis?
This is a process whereby a female mates with a male who has desirable characteristics and this “sexy” trait is inherited by her son and this increases the likelihood that successive generations of females with mate with her offspring.
What is Intra-sexual selection?
This is the mating strategy within the sexes, but it is preferably done by Males
What’s involved in intra-sexual selection?
It involves males competing with other males for access to a fertile female, with the winner of this competition reproducing and passing on the characteristics that contributed to his victory onto his offspring.
What is the male’s optimum mating strategy?
This is to mate with as many fertile females as possible because of the minimal energy required to produce enough sperm to fertilise as many women as possible
What kind of female preference might fertile males have and why?
Fertile males may have a distinct preference for youth and a sensitivity towards indicators of youth. Examples of these indicators of youth include an “hourglass body shape” which is characterised by a thinner waist and a larger hip.
Strength of the evolutionary explanation- *Inter-sexual selection”
A major strength of the sexual selection explanation is the empirical evidence supporting the different mating strategies predicted by anisogamy (the difference between male and female gametes). In a classic study by Buss (1989), which surveyed over 10,000 adults across 33 cultures, he found that women consistently valued good financial prospects, ambition and industriousness while men valued physical attractiveness and youth.
This supports the evolutionary theory of inter-sexual selection because eggs are “expensive” and limited, females are biologically incentivized to be “choosy” and select partners with resources to ensure offspring survival. Conversely, the male preference for youth supports the idea that they are evolved to seek out high reproductive value, strengthening the scientific credibility of the evolutionary model.
However, this research can be criticized for having low temporal validity. In modern society, where women have greater access to their own financial resources, the preference for a “provider” has significantly diminished.
Another strength for Inter-sexual selection
There is strong experimental evidence supporting the idea that females have evolved to be the “choosier” sex to ensure genetic quality.
Clark and Hatfield (1989) conducted a study on a university campus where attractive confederates approached students and asked: “Would you go to bed with me tonight?” They found that 0% of women agreed, whereas 75% of men did.
This dramatic difference in behavior supports the theory of differential parental investment. It suggests that men evolved a “quantity over quality” strategy to increase their reproductive success, while women evolved a “quality over quantity” strategy to avoid the high “cost” of a suboptimal pregnancy. This provides predictive validity for the evolutionary explanation of partner preference.
Despite this, critics argue that this study may measure social desirability bias rather than true evolutionary preference. Women may have said “no” due to the social stigma attached to casual sex (a cultural factor) rather than a biological drive. Ultimately, while the study supports evolutionary patterns, it may underestimate the role of social and cultural influences in female decision-making.
What are the three factors affecting attraction in romantic relationships?
What is self disclosure?
This is the process whereby one reveals personal information about themselves to their romantic partner. It ranges from superficial information (eg, hobbies, favourite music) to deeply personal information (eg, trauma, past fears and hopes)
What is Social Penetration Theory?
This is a theory proposed by Altman and Taylor (1973) which suggests that relationships develop intimacy through a gradual systematic process of self-disclosure, moving from superficial information to more intimate, core, and personal topics.
What are the two elements of self disclosure?
What’s referred to as the “breadth” of information shared?
Breadth refers to the number of topics that can be discussed
What’s referred to as the “depth” of information shared?
Depth refers to how personal the topic being shared is.
What is “Onion” Metaphor used to explain self-disclosure?
Altman and Taylor’s Social Penetration Theory explains relationship development using the onion model. The model suggests that personality is made up of layers, like an onion, with outer layers containing superficial information such as hobbies and interests, and inner layers containing deeper, more personal information, including beliefs, emotions, and core values. As a relationship develops, partners gradually peel away these layers through increased depth and breadth of self-disclosure, leading to greater intimacy and attraction.
Reciprocity as a key concept in self-disclosure.
Reciprocity is a mutual, two-way exchange of self-disclosure, where partners share information at similar levels of intimacy with both partners responding in an appropriate way that is full of understanding and empathy.