Evolutionary explanations of relationship breakdown

Question 1

What are the three possible causes of relationship breakdown?

Answer 1

• Infidelity
• Infertility
• Lack of economic support

Question 2

Betzig (1989) cross-cultural study of divorce

Answer 2

Betzig investigated reasons for marital breakdown using the Human Resources Area Files, a huge collection of materials drawn from anthropological research conducted in a wide diversity of societies of different types.

• She used the Standard Cross Cultural Sample, a specially selected sample of 186 societies designed to be representative of world cultures.
• She investigated what factors were seen as legitimate grounds for divorce in 160 societies where divorce was reported to occur.

Question 3

What was rank-order list of reasons for divorce in societies studied by Betzig?

Answer 3

1. Infidelity
2. Infertility
3. Personality
4. Economics
5. In-laws
6. Absence
7. Health

Question 4

How does this support evolutionary explanations for the breakdown of relationships?

Answer 4

-Infidelity is the highest ranking reason for divorce, and in terms of evolutionary explanations this a factor that would highly effect the reproduction and subsequently the passing of genes for an individual.

Question 5

Identify and explain one key methodological strength of this study.

Answer 5

• One strength is that it is a good cross-cultural study; therefore is not bias to a particular culture - ethnocentric.
• The results were the same across 160 societies, this therefore suggests it is evolutionary as its universal.
• Also a meta-analysis shows a general trend, so shows it is innate.

Question 6

Infidelity: Description

Answer 6

• Evolutionary psychologists would expect infidelity to be the cause of relationship breakdown for men.
• This is because infidelity is more of a threat to men’s reproductive success than to women’s.
• When females cheat the man would not have passed his genes on and this is a large threat to his reproductive success.
• This means that men would be most upset by the sexual aspects of infidelity.
• However if a man cheats she does not lose the opportunity to have a child herself, but the male may divert resources towards the other woman, especially if she has a child by him.
• This means that women should be most upset by the emotional aspects of infidelity

Question 7

Infidelity: Cross-cultural evidence on divorce

Answer 7

• Betzig found that infidelity was the single most cited reason for divorce in over half of the societies in her cross- cultural study.
• Adultery by either partner was grounds for divorce in 28% of societies; adultery by females alone in 61% of societies and by males alone in 2% of societies.
• This suggests that there is a double standard: adultery by men seems to be considered less unacceptable in more societies.

Question 8

Official stats on divorce

Answer 8

• Official divorce statistics collected by governments show that men are twice as likely as women to cite sexual infidelity as a reason for divorce.
• This is despite the fact that men are twice as likely to be unfaithful as women!

Question 9

Are divorce stats valid?

Answer 9

• Social desirability effects?
• Valid to an extent, but there are other factors
• Limiting to just married couples

Question 10

Evidence for sex difference responses to types of infidelity:

Answer 10

In a questionnaire buss found that:

• Men were more upset by the threat of sexual infidelity than women
• Women were more upset by the threat of a man diverting his resources towards another woman, rather than the sexual infidelity itself.

Question 11

Buunk et al. (2002)

Answer 11

• Buunk et al. examined these sex differences in three parallel studies conducted in the Netherlands (N=207), Germany (N=200), and the United States (N=224). Two key findings emerged.
• First, the sex differences in sexual jealousy (i.e., men show more distress at sexual infidelity and women at emotional infidelity) are robust across these cultures, providing support for the evolutionary psychological model.
• Second, the magnitude of sex differences varies somewhat across cultures – large for the US, medium for Germany and the Netherlands.

Question 12

Buunk et al, evaluation

Answer 12

• Cross-culture; innate - implies its evolutionary
• Results were robust across these cultures
• But all the samples are western and so not completely generalisable

Question 13

Infertility: Description

Answer 13

• If one partner is unable to have children, then the other may be motivated to leave the relationship, as this makes it impossible to get their genes into subsequent generations.
• This makes it likely that the belief that the other person is infertile would lead to the end of the relationship.

Question 14

Infertility: Evidence

Answer 14

• Infertility was 2nd in Betzig’s league table of causes of divorce.
• Fisher (1989) looked at 31 years of data from 45 countries and found that the modal number of children at divorce = 0 in 62% of societies.
• A UN study of 45 societies found that 39% of divorces occur when there are no children, compared to 26% when there is a single child and 19% when there are two children.

Question 15

How could these results be used as evidence for the role of infertility in relationship breakdown?

Answer 15

-Evidence for relationship breakdown because the highest rate of divorce for number of children is 0, therefore they have not passed down their genes and leave the relationship

Question 16

Explain one limitation of these findings as support for the evolutionary explanation.

Answer 16

• Doesn’t directly show that they didn’t have the children because they were infertile so therefore implicit, indirect evidence
• Temporal vality (1989) and and extra 31 years previously- divorce was more difficult and less common
• Also they they knew that the relationship wasn’t working they may have deliberately chose not to have children

Question 17

Lack of economic support: Description

Answer 17

• Evolutionary psychologists would expect lack of economic support to be a major cause of divorce, with failure of males to provide resources more likely to be a factor than by females.
• Given the expectation that females will be attracted to males who provide resources and have the status to provide such resources in the future, we would expect loss / lack of such resources / status to predict marital breakdown.

Question 18

Lack of economic support: Evidence

Answer 18

• ‘Economics’ was 4th in Betzig’s league table of causes of divorce.
• Inadequate economic support, including lack of provision of housing, food, etc) was the major factor in predicting females divorcing males (but not vice versa) in around 20% of societies.
• In the US, the divorce rate is 50% higher among women who earn more than their husbands than in marriages where the husband earns more.
• A drop in the level of resource provision (e.g., through loss of a job) is also associated with an increase in divorce citations by females, but not by males.

Question 19

Can you identify an alternative explanation for any of these findings?

Answer 19

• Divorce could be a result of the man feeling emasculated by the women’s success; as in the EEA men were meant to the providers
• Loss of a job could lead to other personality traits that break down the relationship