Psychology Relationships Evolutionary explanations for partner preferences

What is the evolutionary explanation of sexual selection?

Idea that partner preference evolved because they increased reproductive success and helped pass on genes

Why do humans seek certain trats in partners according to the evolutionary theory?

Because traits that improve offspring survival and reproductive success are naturally selected (help organisms survive and or reproduce making genes more likely to be passed onto offspring)

What are two types of sexual selection relevant to human relationships ?

Inter sexual selection and intra sexual selection

What does inter and intra selection explain?

They explain why males and females evolved different partner preferences and mating behaviours

What is anisogamy ?

The difference in male and female gametes as there are many sperm but limited eggs leading to female choosiness (influencing mating strategies of females, why they are more cautious when choosing mate)

What is inter sexual selection?

Selection between sexes where one sex (usually females) chooses a mate based on desirable traits / characteristics

Why does anisogamy make females the choosier sex?

Because pregnancy is a high investment process so females must avoid mating with an unsuitable partner

Why are females typically choosier in intersexual selection?

Because they invest more biologically in reproduction and risk pregnancy

What traits do males typically prefer in females according to evolutionary theory?

Youth and physical attractiveness which signals fertility

Clear skin

Large breasts (for breast feeding)

Waist to hip ratio (of ideal 0.7)

Large hips (child bearing)

What traits do females typically prefer in males according to evolutionary theory?

Resources , status and ambition which signals the ability to provide for offspring

Financial stability

Commitment

What is intra sexual selection?

Competition within one sex (usually males) for access to mates often leading to traites like increased size, aggression and strength

Why do males compete with each other in intra sexual selection?

Because males maximise reproductive success by gaining access to multiple fertile females

(the best way to pass on there genes it to gain access to females that are likely to reproduce e.g young)

What traits in males are favored through intra sexual selection?

Strength , dominance , competitiveness and risk taking

What is the difference between inter and intra sexual selection?

Inter‑sexual selection

where one sex (usually females) chooses a mate based on desirable characteristics or behaviours, such as displays of resources, status, or courtship behaviours.
This reflects female choosiness because females invest more in reproduction.

Intra‑sexual selection

where members of the same sex (usually males) compete with each other for access to mates.
This competition favours traits like strength, dominance, aggression and risk‑taking, helps males defeat rivals and gain access to fertile females.

What traits are favoured in males through intra sexual selection?

Strength , dominance, competitiveness and risk taking

How does sexual dimorphism relation to intra sexual selection?

Males evolved to be larger and stronger due to competition while females did not need these traits

What is sexual dimorphism?

Difference in form, colour , size, and behaviour between males and females

What did buss investigate in his cross cultural study?

Sex differences in mate preference across 33 countries

What did buss find about female partner prefrences?

Females preferred males with resources status and ambition

What did Buss find about male partner prefrences?

Males preferred younger , physically attractive females signalling fertility

How does Busses findings support evolutionary explanations of sexual selection?

It shows consistent sex differences across cultures suggesting evolved preferences

What is one limitation of buss?

Social desirability bias could be present as he used self report data

Temporal validity - conducted in the 1990s gender roles have changed since then and become more fluid

Ethnocentrism - due to globalisation most countries are influenced by western gender norms so may reflect cultural stereotypes

What are strengths of Buss’s cross cultural study?

Ecological validity - as this is evident in real world where young youthful women get into relationships with old wealthy men

High reliability - Buss used interviews as well as questionnaires and found the same pattern

Cross cultural consistency - suggesting universiality

What was the aim of Clack and hatfields study?

To test sex differences in willingness to engage in casual sex

What did clark and hatfield find about male responses?

Around 75% of males agreed to casual sex with strangers

What did Clark and Hatfield find about female responses to casual sex?

0% agreed to casual sex with a stranger

How does Clark and Hatfield’s study support evolutionary theory?

Shows that females are choosier due to higher reproductive investment while males pursue more mating opportunities

What are strengths of Clark and Hatfilds’s study involving casual sex?

High ecological validity - field experiment in real life on a university campus

Strongly supports the evolution theory

Replicable- replicated across different culture and found the same results increasing the reliability

What are limitations into Clark and Hatfield’s sudy involving casual sex?

Ethical concern - lack of informed consent and invasion of privacy which could have lead to embarrassment

Sampling bias- all participants were american college students so not representative

Demand characteristics - men could have felt like they had to say yes because of social expectations , they wanted to be socially rewarded

What did Ronay an dvon Hippel investigate with skateboarders? What did they find?

Investigated whether males take more physical risks in the presence of an attractive female

Found male skateboarders took greater risks when observed by an attractive female

How does Rony and von hippel support intra sexal selection?

It shows males display risk taking to compete for female attention

What studys support intra sexual selection?

(males compete)

Ronay and Von Hippel (skateboarding)

What studys support inter sexual selection?

(Females are choosy)

Clarke and hatfield (American collage)

Buss (cross cultrual)

What were strengths and weaknesses of Ronay and con Hippel (skateboarding) study?

Strengths

High ecological validity - Real skateboarders in a real skateboard park

Controlled manipulation - they were either watched by male researcher or attractive female

Limitations

Sample bias - young male skateboarders in Australia is not representative of all males

Cultural bias- conducted in australia which has holds western norms so cannot be generalized

Why is the evolutionary theory criticised for lacking temporal validity?

Modern day women can provide for themselves , reducing the importance of male resources

Why is the evolutionary theory criticized for heteronormativity?

Heteronormativity - assumption that being hetrosexual is the defalt / norm

It only explains hetrosexual reproduction and ignors LGBTQ reslationships

Why is the evolutionary theory considered reductionist ?

Resources complex human relationships to reproductive drives