Evolutionary theories

Question 1

Outline sexual selection.

Answer 1

Certain genes encourage greater possibility of reproduction. These genes are passed on through successful mating and becoming adaptive.

Question 2

Give the 3 predictions associated with sexual selection.

Answer 2

1. Women will be choosier than men, showing less interest in short term liaisons.
2. Women will be attracted to properties that suggest a willingness to invest.
3. Men will be attracted to indicators of fertility.

Question 3

Give three studies which support prediction 1 of the sexual selection theory:
“Women will be choosier than men, showing less interest in short term liaisons.”
One study was replicated, why?

Answer 3

Clarke and Hatfield (1989)
- 75% of men agreed to have sex with a stranger. No women did.
Clarke (1990)
- Replicated the above study to avoid the problem of stranger danger. The same results were found.
Buss & Schmidt
- Men on average wanted 18 lifetime partners, women wanted 4/5.

Question 4

Give two studies which support prediction 2 of the sexual selection theory:
“Women will be attracted to properties that suggests a willingness to invest.”

Answer 4

Dunbar & Waynforth (1995)
- Content analysis of lonely hearts ads. Men indicated wealth 1.7x more than women. Women asked for wealth 4.5x more than men.
Buss (1989)
- Cross-cultural questionnaire. Men cite youth and good looks as important when selecting a sexual partner. Women cited financial prospects and emotional maturity.

Question 5

Give two studies which support prediction 3 of the sexual selection theory:
“Men will be attracted to indicators of fertility.”
What does one of the studies show in regards to an IDA point?

Answer 5

Singh (1993)
- Playboy centrefolds and Miss America pageant winner analysis found a waist hip ratio of 0.7 most desirable.
Karremans (2010)
- Blind men preferred a waist hip ratio of 0.7. Shows sexual selection in nature based not nurture based.

Question 6

Give a study which goes against prediction 3 of the sexual selection theory:
“Men will be attracted to indicators of fertility.”

Answer 6

Strassberg and Holty (2003)

- Placed 4 ads in a lonely hearts column. The most successful ad stated financial independence, not image.

Question 7

Give two negative IDA points of sexual selection theory.
One of these points has a study attached.
A study can be used to respond to one of the IDA points. Identify it.

Answer 7

Nature vs nurture
- The evolutionary theory places too much emphasis on nature.
R: Karremans (2010)
Gender (alpha) bias
- Buss found both men and women rate kindness and intelligence highly.

Question 8

Give three possible evolutionary causes for breakdown in a relationship.
Explain how they are evolutionarily motivated.

Answer 8

1. Infidelity
   - Paternal certainty and investment.
2. Infertility
   - Inability to pass on genes.
3. Lack of economic support
   - Less investment leads to a greater chance of infant mortality.

Question 9

Give 3 studies which support evolutionary reasons for breakdown.
Give a control problem for one of these studies.

Answer 9

Betzig (1989)
- Reasons for divorce recorded cross-culturally:
1. Infidelity 2. Infertility 3. Economics.
Buunk (2002)
- Men exhibit greater stress at sexual infidelity. Women exhibit greater stress at emotional infidelity.
Fisher (1989):
- Modal number of children at divorce is 0 in 62% of societies. TIME IS NOT CONTROLLED FOR HERE.

Question 10

Give two negative IDA points for the evolutionary theory of relationship breakdown.

Answer 10

Alpha-bias
- Suggests men and women are different in regards to infidelity, suggesting they will only respond most severely to one type of infidelity.
Deterministic
- Suggests named factors always cause breakdown. This is not always true.

Question 11

Give 3 factors which affect parental investment.

Answer 11

1. Whether and how closely A is related to C.
2. How certain A is of genetic relatedness.
3. Possible number of offspring that person can produce.

Question 12

Give two studies which support the parental investment theory. Give the factors the apply to.

Answer 12

Geary (1989)
- Fathers spend less time than mothers interacting with their children in all cultures. Paternal certainty.
Euler and Weitzel (1996)
- Maternal grandmothers care most for their grandchildren. Paternal grandfathers care the least. Paternal certainty.

Question 13

Give a study which goes against the parental investment theory.
How can you explain this finding in evolutionary terms.

Answer 13

Anderson
- A father does not discriminate between his biological children and his step-children when providing monetary funds for college fees.
The father may invest more to demonstrate his willingness to invest to his partner.