Sexual selection: anisogamy
- Difference between male and female sex cells…
Sperm = continuously produced from puberty - old age, small, mobile. Ova = larger, static and produced at intervals for a limited number of years. - Mating strategies…
Plenty of fertile males, fewer females.
Sexual selection: inter-sexual selection
Selection of mates between sexes.
- Female strategy: quality over quantity. Greater investment of time so they need to be choosier than males - seek a man who will provide healthy offspring.
- Impact on mating behaviour: preferences of both sexes determine attributes that are passed on, e.g. height.
Sexual selection: intra-sexual selection
Selection of mates within sexes.
- Male strategy: quantity over quality. Competition is necessary because females are a limited resource and are choosy.
- Impact on mating behaviour: pressures lead to certain patterns of human reproductive behaviour -
Male aggression: most aggressive males = more likely to reproduce.
Male preference for youthful and fertile women because these are signs of fertility leading to reproductive success.
Evaluation of sexual selection
✓ Buss - surveyed over 10,000 adults in 33 countries asking about partner preferences. Females valued resource-related characteristics more than males. Males valued reproductive capacity - supports intra-sexual selection.
✓ Clark and Hatfield - no females agreed to requests, 75% of males agreed. Shows choosiness of females.
✓ Waist-hip ratio research - Singh measured waist-hip ratio preferences of males for females. Ratio of one to the other = 0.7 (thought to signify fertility) - evolutionary factors are reflected in patterns of HR behaviour through partner preferences.
✓ Support from lonely hearts research - Waynforth and Dunbar: lonely hearts ads in newspapers, found women tended to offer physical attractiveness and indicators of youth
✗ Ignores social and cultural influences - Chang et al. found some preferences have changed and others have remained the same over 25 years in China - evolutionary and cultural influences must be taken into account.
Factors affecting attraction: self-disclosure
Important early in a relationship, involves revealing intimate information e.g. likes, hopes, fears, attitudes.
Self-disclosure: Social Penetration Theory, Altman and Taylor.
- Self-disclosure is limited at the start.
- Revealing personal information = a sign of trust.
- Partner has to reciprocate and reveal personal information.
- ‘Penetration’ leads to development = greater understanding of each other.
- Breadth is narrow at the start of a relationship, if too much information is revealed it is off-putting.
- Depth - as the relationship develops, more layers are gradually revealed.
Reciprocity of self-disclosure, Reis and Shaver
Reciprocity is key.
Successful relationships all involve disclosure from one partner, and this should be received sensitively by the other partner. This leads to further self-disclosure.
Evaluation of Self-Disclosure
✓ Sprecher and Hendrick: strong correlations between satisfaction and self-disclosure in heterosexual couples. Those who reciprocated self-disclosure were more committed to their romantic relationship.
✓ Real-life applications: Hass and Stafford - 57% of gay men and women reported that open and honest self-disclosure was a maintenance strategy. Theory can be used to support people having relationship problems.
✓ Links to relationship breakdown: Duck’s phase model of the breakdown of relationships - couples often discuss their relationship with each other in intimate detail yet this may not be enough to save their relationship.
✗ Doesn’t apply to all cultures: Tang et al. found individualist cultures self-disclose significantly more sexual thoughts and feelings than collectivist cultures. Pattern of self-disclosure is different.
Factors affecting attraction: physical attractiveness
- Symmetry
Shackelford and Larsen found people with symmetrical faces are rated as more attractive = signal of genetic fitness.
The associated ‘robust’ genes are likely to be passed on and symmetry is perpetuated.
We have evolved a liking for attributes that signal high quality = evolutionary.
Factors affecting attraction: physical attractiveness
- Baby face features
Neotenous features trigger protective and caring instincts relating to the formation of attachment in infancy.
- features that strengthen attachment are adaptive.
Factors affecting attraction: physical attractiveness
- McNulty
Attractiveness is an important feature of the relationship throughout, even after marriage.
Factors affecting attraction: physical attractiveness
- Halo effect
Physical attractiveness is generalised.
Dion et al. found physically attractive people are consistently rated as kind, strong, sociable, successful.
Factors affecting attraction: physical attractiveness
- Matching hypothesis
Walster et al. found we choose a partner whose attractiveness matches ours.
Choosing a partner is a compromise - evolutionary theories suggest women should seek the most attractive males. However, we have to balance the potential for being rejected.
Evaluation of Physical Attractiveness
✓ Research support for halo effect - Palmer and Peterson: physically attractive people were rated more politically knowledgeable and competent. This suggests politicians may be elected based on attractiveness. Halo effect can be observed in real-life situations.
✓ Cunningham et al. found large eyes, small nose and prominent cheekbones were rated as highly attractive by white, Asian and Hispanic males. Physical attractiveness is culturally consistent and may have evolutionary roots.
✗ Individual differences in the importance placed upon physical attractiveness - may not be as significant a consideration in relationship formation for all partners.
✗ Online dating research hasn’t supported its assumptions - Taylor et al. found online daters sought dates with partners who were more attractive than themselves. Doesn’t support matching hypothesis.
Factors affecting attraction: filter theory, Kerckhoff and Davis
Explains attraction in terms of attitudes and personalities.
- We consider the filed of availables.
- We select the field of desirables via three filters of varying importance at different stages of a relationship.
First level of the Filter Theory
Social Demography
- Geographical locations, social class, education - more likely to meet and have meaningful encounters with people who are physically close and share other features with yourself.
- Anyone who is too ‘different’ is filtered out before the next stage.
Second level of the Filter Theory
Similarity in Attitudes
- Sharing values and beliefs.
- Agreeing on basic values promotes better communication and self-disclosure in early stages of a relationship.
Byrne found similarity in attitudes causes mutual attraction - often, without this, the relationship fades after only a few dates.
Third level of the Filter Theory
Complementarity
- Partners need to meet each other’s needs.
- Important for longer term/ later stages of a relationship.
Evaluation of the Filter Theory
✓ Research support: Winch found similarity of personality, interests and attitudes between partners are typical of early stages of a relationship. This suggests that filters may determine the development of the relationship = validity.
✗ Lack of replication of original findings: Levinger found social change and difficulties in defining the depth of a relationship could be a reason for the lack of replicability.
- Kerckhoff and Davis assumed partners together over 18 months were more committed, may not be the case in cultures today.
✗ Lack of temporal validity - dating world has changed. Online dating means social demography has taken less importance. Dating someone outside our culture not predicted in original filter theory.
Theories of romantic relationships: Social Exchange Theory, Thibault and Kelley
Relationships can be explained in terms of economics.
- Satisfaction is judged in terms of profit. Partners are motivated to minimise the costs to themselves whilst maximising rewards.
- Costs include loss of time, stress.
- Rewards include sex, praise and companionship.
Social Exchange Theory: CL and CLalt
- CL: Comparison level = a judgement of the reward level we expect in a relationship, determined by relationship experiences and social norms.
- CLalt: Comparison level for alternatives = considering whether we might gain more rewards and endure fewer costs in a different relationship.
Duck - if costs of our current relationship outweigh the rewards then alternatives become more attractive. If we are in a satisfying relationship, we may not even notice them.
Social Exchange Theory: 4 Stages of a Relationship
Sampling: exploring rewards and costs by experimenting in our relationships and observing others.
Bargaining: at the start of a relationship - partners negotiate around costs and rewards.
Commitment: relationships become more stable. Costs reduce, rewards increase.
Institutionalisation: when partners become settled because the norms of the relationships are established.
Evaluation of SET
✗ Research involves artificial tasks and conditions - ‘partners’ are together just for a study. More realistic studies use real partners who have been less supportive of SET. Lack of validity of studies.
✗ Doesn’t consider equity - focuses on comparison levels but ignores the fact that many romantic partners desire fairness or equity. Hatfield found that couples in equitable relationships were more satisfied than those who saw themselves as over/ under-benefitting. Limited exp of relationships.
✗ Assumes all relationships are exchange based: Clark and Mills - exchange relationships may involve profit (work colleagues) but communal relationships (romantic partners) involve giving and receiving without thinking of profits. SET may not provide a suitable explanation for all types of relationships.
Theories of romantic relationships: equity theory
Role of equity: Walster et al. propose that equity is more important where both partner’s level of profit should be roughly the same.
Under-benefitting and over-benefitting can lead to dissatisfaction.
Equity is about the fairness of the ratios.
