Evolutionary Explanations Flashcards
Evolutionary Explanations of Partner Preferences
According to evolutionary psychology, partner preferences are driven by sexual selection. This means that both males and females choose partners in order to maximise their chances of reproductive success. Individuals with traits that maximise reproductive success (e.g. strength, height, aggression, wide hips etc.) are more likely to survive and pass on the genes responsible for their success.
Males have gametes (sperm cells), which are able to reproduce quickly with little energy expenditure. Female gametes (eggs or ova) are much less plentiful and require far more energy to produce. This difference (anisogamy) means that males and females use distinct strategies to choose a partner. Generally males use intra-sexual selection and females use inter-sexual selection.
Intra-Sexual Selection
Intra-sexual selection is where members of one sex (usually male) compete with one another for access to the other sex. This leads to male-female dimorphism, which is accentuation of secondary sexual characteristics in those with greater reproductive fitness.
Anisogamy in Intra-Sexual Selection
Anisogamy suggests that a male’s best evolutionary strategy is to have as many partners as possible. Males must compete with other males to present themselves as the most attractive mate to fertile female partners.
Males might engage in mate guarding where they guard their female partner to prevent them mating with anyone else. Males are very fearful of having to raise another man’s child, this is called cuckoldry
Inter-Sexual Selection
Inter-sexual selection is between (inter) the sexes: the strategies that makes use to select females or females use to select males. Inter-sexual selection is the preferred strategy of the female, quality over quantity.
Anisogamy in Inter-Sexual Selection
Anisogamy suggests that a women’s best evolutionary strategy is to be selective when choosing a partner. Females will tend to seek a male who displays characteristics of physical health, high status, and resources. Thus the male partner is able to protect them and provide for their children. Although this ability may have equated to muscular strength in our evolutionary past, in modern society it is more likely to relate to occupation, social class and wealth.
Advantages of Evolutionary Explanations of Partner Preferences
+ Buss (1989) conducted a survey of over 10,000 adults in 33 countries and found that females reported valuing resource-based characteristics (such as occupation) whilst men valued good looks and preferred younger partners.
+ Clark and Hatfield (1989) conducted a now infamous study where male and female psychology students were asked to approach fellow students of Florida State University (of the opposite sex) and ask them for one of three things; to go on a date, to go back to their apartment, or to go to bed with them. About 50% of both men and women agreed to the date, but whilst 69% of men agreed to visit the apartment and 75% agreed to go to bed with them, only 6% of women agreed to go to the apartment and 0% accepted the more intimate offer.
Disadvantages of Evolutionary Explanations of Partner Preferences
- The evolutionary approach is deterministic suggesting that we have little free-will in partner choice. However, everyday experience tells us we do have some control over our partner preferences.
- Evolutionary approaches to mate preferences are socially sensitive in that they promote traditional (sexist) views regarding what are ‘natural’ male and female behaviors which do not apply to modern society. Women are now more career orientated and independent therefore will not look for resourceful partners as much as they may have had to in decades past. Additionally, the availability of contraception means that evolutionary pressures are less relevant.
- Evolutionary theory makes little attempt to explain other types of relationships, e.g. non-heterosexual relationships, and cultural variations in relationships which exist across the world, e.g. arranged marriages
Male strategies have evolved seeking to maximise opportunities for mating success including:
Courtship rules - allow males to display genetic potential, through characteristics and resource abilities
Size - males evolved to be bigger, demonstrating strength for success in competition against other males. This includes weaponry in some species such as antlers in deer
Sperm competition - natural selection acted on males, making them more competitive by producing larger testicles, bigger ejaculations and faster swimming sperm
Mate guarding - males fear being ‘cuckhold’ (where another male gets their partner pregnant) and spending resources raising another male’s child. Males therefore indulge in mate guarding, where they keep an eye on and remain in close contact with female partners to prevent them mating with other males. Buss (1993) believes while men are fearful of partners being sexually unfaithful, females worry about emotional unfaithfulness, due to a fear of their partner spending resources on other females.
Sneak copulation - males mate with other females if given the opportunity so that they can increase their chances of reproductive success. Women gain from this too as by their offspring having different fathers, increases the wider genetic diversity of their children which in turn increases survival.
Female strategies that have evolved include
Sexy sons hypothesis - this was devised by Fisher (1930) who argued that females select attractive males as they will produce sons with the same attractive features, increasing their sons and thus their own reproductive fitness
Handicap hypothesis - Zahavi (1975) believes females select males with handicaps, demonstrating superior genetic quality. This may explain females finding males attractive who drink and take drugs in large quantities as they are able to handle them showing genetic fitness
Courtship - females use courtship to select males in the basis of reproductive fitness, through males demonstrating strength, health and ability to provide resources. Prolonged courtship benefits females as they make males invest time, effort and resources, increasing the chances of males not deserting their partners after successful matings.
