Relationships Flashcards
What is Darwin’s theory of sexual selection?
Humans attracted to people that aid successful reproduction
Evolution favours development of attractive features
These features make it more likely someone will attract a mate -> reproduce -> pass on genes
What is the definition of anisogamy?
The differences between male and female gametes
How are sperm cells and egg cells different? (anisogamy)
Small vs Large
Mobile vs Static
Created constantly vs produced in intervals for limited fertile years
Little energy vs significant energy investment
What is the consequence of anisogamy?
No shortage in fertile males but fertile females are rarer
Means making a wrong partner choice more serious for females due to greater investment -> choosy
What does anisogamy give rise to?
2 types of sexual selection…
Inter-sexual (females)
Intra-sexual (males)
Why is inter-sexual selection the preferred strategy for females?
Quality > quantity as ova rarer than sperm
Thus, consequences of female making wrong choice more serious, so makes sense to be more selective
Optimum to select genetically fit partner to provide resources
Female preference determines features passed on to offspring
What is the ‘Sexy sons’ hypothesis (Fisher)?
When females mate with male with certain trait, sons inherit this ‘sexy’ trait
Sons more likely to be selected, preference for ‘sexy’ trait is maintained + exaggerated (runaway process)
Why is intra-sexual selection the preferred strategy for males? What does this entail?
Quantity > quality) as low investment cost
Competition between males to be selected as a mate: winner reproduces and passes on characteristics
What does intra-sexual selection give rise to?
Male-female dimorphism… males and females end up looking very different
Give examples of male-female dimorphism
Physical size b/w males matters -> larger males more likely to reproduce successfully, but not evolutionary advantage for females (not as big)
Youthfulness + waist/hip ratio preferred for female -> more likely to be selected
Who did research into waist-hip ratio?
Singh
- Males find any hip and waist size attractive, as long as ratio is 1:0.7
- Wide hips signal fertility BUT slimmer waste shows not already pregnant
- Prevents cuckoldry
What are the behavioural consequences of intra-sexual selection for males?
Deceitfulness, aggression (mate-retention strategies) -> selection of aggressiveness
What are 2 strengths of the evolutionary explanations for partner preferences?
Research support for inter-sexual selection (female choosiness)
- Clark + Hatfield
- sent male/female students to approach other students (of opposite sex)
- told them they found attractive and asked, ‘would you go to bed with me tonight?’
- no females agreed but 75% of males did immediately
Supports view that females are choosier when selecting sexual partner across cultures
Research support for predicting intra-sexual selection
- Buss
- survey > 10,000 adults, 33 countries
- questions about attributes that evolutionary theory predicts are important in partner preference (but self-report)
- females valued resource related characteristics (eg: ambition)
- males valued attractiveness & youth (as have good reproductive capacity)
Reflects consistent sex differences in partner preference, supports prediction from sexual selection theory, cross cultural so evolutionary valid
What are 2 weaknesses of the evolutionary explanations for partner preferences?
Sexual selection theory too simplistic that one strategy is adaptive for all males and other is adaptive for all females
- strategies differ according to length of relationship
- sexual strategies theory argues that males & females adopt similar mating strategy (choosy) when seeking LT relationships
This is a more complex + nuanced view of how evolutionary pressures influence partner preference, considers context of reproductive behaviour
Cannot explain partner preferences of gay/lesbian
- homosexual partners not assessing genetic fitness (though they may assess other qualities relevant to caring for offspring)
- because they can’t reproduce together
Evolutionary theory limited in explaining partner preferences amongst homosexuals
BUT
- Lawson et al looked at personal ads and found the preferences of homo/heterosexual men or women same as theory
What are the 3 factors affecting attraction in romantic relationships?
Self-disclosure
Physical attractiveness
Filter theory
What is self-disclosure?
Revealing personal information about yourself
Reveal more as relationship develops, can strengthen romantic bond
Who developed the social penetration theory?
Altman + Taylor
What is the social penetration theory?
Gradual process of revealing inner self to other: displays trust
Reciprocal exchange of information between partners
As more is disclosed, partners ‘penetrate’ deeper into each other’s lives
Eventually relationship reaches certain level where self-disclosure welcome
What is depenetration?
Dissatisfied partners self-disclose less to disengage from relationship
What are the 2 elements of self-disclosure?
Breadth and depth
Talk about self-disclosure at the start of a relationship
Reveal a lot (breadth)
But just superficial layer, range of topics limited (little depth)
Talk about self-disclosure as a relationship develops
Becomes deeper to reveal true self, removal of layers
What is a key principle to develop in both breadth and depth of self-disclosure?
Reciprocity
What did Reis and Shaver say about how reciprocity works in a relationship?
When self-disclosing, you want your partner to respond with understanding and empathy + share their own thoughts and feelings
Leads to a balance of self-disclosure between both partners in successful romantic relationship -> increases intimacy + deepens the relationship