Evolutionary explanations for partner preferences

Question 1

A01

What is an evolutionary explanation of sexual selection?

Answer 1

• Darwins Evolutionary explanations of sexual selection based on the idea that human beings seek to continue their genetic line using mechanisms of adaptation to ensure their survival (achieved via reproductive success)
• sexual selection- means selecting a partner who is likely to give offspring the best chance of survival & further reproduction
• traits deemed attractive by males & females are distinct and have different functions according to evolutionary psychology

The evolutionary explanation of sexual selection is based purely on opposite-sex attraction

Question 2

A01

Outline Anisogamy

Answer 2

Anisogamy refers to the differences between male & female sex cells( gametes)
* Male gametes (sperm)-are small, highly mobile & created continuosly from puberty to old age, do not need much energy to produce
* Female gametes( eggs) relatively large, static, produced at intervals for limited number of fertile years & require energy.
These differences mean that females & males adopt different strategies to achieve reproductive success
Anisogamy gives rise to 2 types of sexual selection:
Inter-sexual selection
Intra-sexual selection

Question 3

A01

Outline inter-sexual selection

Strategy for females

Quality over quanity

Answer 3

Inter sexual selection is between the sexes-
The preferred strategy of females, based on idea that females place a greater investement of time, energy & resources in raising offspring- look for quality over quantity
thus,Females optimum mating strategy is to select a genetically fit partner who is able to provide resources

This female preference determines which features are passed on to the offspring i.e if height is considered an attractive male trait by females then it would increase in the male population over successive generations

Question 4

A01

Outline intra-sexual selection

Strategy for males

Answer 4

Intra-sexual selection is within each sex .
Preferred strategy of the male to be selected , quantity over quality
There is a competition between males to be selected to mate with a female.
The winner of the competition reproduces & characteristics that contributed to his success are passed on to offspring-led to physcial demorphism

Question 5

A01

Outline how intra sexual selection led to physical demorphism

Answer 5

This strategy has led to physical dimorphism( 2 forms)- males & females end up looking very different because of intra-sexual selection.
I.e the differences in body size & physical appearance between both sexes.
As males need to compete with other males to access fertile female mate,
sexual selection favours physcially strong & aggressive males.
As females do not need to physically compete for males’ attention they have evolved to be smaller, less muscular,lesscompetitive so their is no evolutionary drive towards favouring large females.

Question 6

A03

research support inter-sexual selection
-Clark & hatfield-female choosiness

Strength

Answer 6

Evidence supporting the specific role of female choosiness in heterosexual partner preferences
Clark & Hatfield-conducted field experiment, sent male & female students out across uni campus where they approached other students asking if they would ‘ go to bed with them’’ these strangers were of the opposite-sex ( same age & deemed to be ‘attractive): 75% of the males said yes to this request; not one of the females did.
supporting the view that females are choosier than males when selecting a sexual partners & that males evolved a diff strategy to ensure reproductive sucess

Question 7

A03

Outline research support for Intra-sexual selection-buss-buss

Strength

Answer 7

Buss(1989) conducted a cross-cultural survey over 33 countries
found that females prefer male partners who have resources & traits such as ambition whereas males prefer younger female partners who are attractive & fertile
These findings reflect consistent sex differences in partner preferences & supports sexual selection theory

Question 8

A03

Limited application to LGBTQ community

Limitation

Answer 8

Evolutionary theory is solely concerned with heterosexual mating preferences and reproduction which means that it has limited applicability to homosexual people and to the LGBTQ community as a whole

theory does not account for major social & cultural changes which may affect reproductive behaviour. There is some evidence of changes to mate choice preference following changes such as the lack of female dependency on a partner.