Sexual selection
An evolutionary explanation of partner preference. Attributes or behaviours that increase reproductive success are passed on and may become exaggerated over succeeding generations of offspring.
Examples of traits that provide advantages for mating in humans
Aggression, greater height, certain facial and bodily features
Anisogamy
Refers to the differences between male and female sex cells (gametes)
Males (sperm)
Females (eggs)
Intersexual selection
Between the sexes, the strategies that males use to select females or females use to select males (the preferred strategy of the female - quality over quantity)
Which sex is choosier?
Women
What do females typically choose in evolutionary theory?
A partner who can offer resources, who has money status and ambition
An example of the runaway process
If height is a male trait then, over successive generations of females, it would increase in the male population because females would mate with tall males, and over time, produce sons who are taller with each generation and produce daughters who have a greater preference for tall partners.
This may result in a feature becoming exaggerated over many generations.
Sexy sons hypothesis
Where a female mates with a male who has desirable characteristics, and this ‘sexy’ trait is inherited by her son. This increases the likelihood that successive generations of females will mate with her offspring
Intrasexual selection
Within each sex - such as the strategies between males to be the one that is selected (this is the preferred strategy of males - quantity over quality)
Dimorphism
The obvious differences between males and females
Which strategy gives rise to dimorphism?
Competition between males where the victor reproduces and gets to pass on his winning characteristics to the offspring
The optimum reproductive strategy for males
To mate with as many fertile females as possible. This is because of the minimal energy to produce sperm and the relative lack of post-coital responsibility
Buss (1989)
Clark and Hatfield (1989)
Other factors influencing mate preferences aside from evolutionary explanations
Chang (2011)
Support for waist-hip ratio (WHR)
Support from lonely hearts adverts
Self-disclosure
Altman and Taylor’s social penetration theory (1973)
6 levels involved in social penetration theory
1) Biographical data (age, gender, name)
2) Preference in clothes, food and music
3) Goals and aspirations
4) Religious convictions
5) Deeply held fears and fantasies
6) Concept of self
Breadth and depth