Lesson 7 - Genetics and Evolution

Question 1

Strengths of genetics

Answer 1

• Gene mapping can help locate genes on chromosomes, and this is a very scientific and controlled practice.
• Involves twin and adoption studies, and this is particularly useful when looking at monozygotic (MZ) twins
• Gene mapping can help psychologists and doctors screen patients and see if they have a gene for an illness and this may help prevent the illness from taking shape

Question 2

Weaknesses of genetics

Answer 2

• It is reductionist, as it takes a complex function like IQ or illnesses and reduces it to a simple component like genes. These processes or behaviours can have a number of different factors
• It does not take into account other approaches in psychology, like the cognitive or behavioural approaches, as an illness like depression may be caused by a gene, but the patient also may harbour negative internal thoughts or they may have learned the behaviours associated with depression

Question 3

Gottesman and Shields

Answer 3

• Investigated 224 sets of twins from 1948-1993

Dizygotic - 118
Monozygotic - 106

• Avg. 46 years old
• Longitudinal study conducted in London over 25 years
• Relied on the fact that one twin already had schizophrenia, and they examined the concordance rates, the likelihood of the healthy twin developing the illness over time
• They used doctors case notes, the DSM and in depth interviews

Question 4

Results of Gottesman and Shields

Answer 4

48% of monozygotic twins were both concordant

17% of dizygotic twins were both concordant

This supports the argument that schizophrenia can be transmitted through genes

Question 5

Strengths of Gottesman and Shields

Answer 5

• It is longitudinal, and this increases the reliability of the study by tracking changes over a long period of time. It allows you to monitor the development of the illness.
• Supports the idea that illnesses and behaviours can be transmitted genetically

Question 6

think about the fact that they’re twins

Weaknesses of Gottesman and Shields

Answer 6

• The research ignores the behavioural approach, as it is important to consider that twins tend to copy and imitate each other’s behaviours, and it needs to be investigated whether the illness was transmitted genetically or through observation.
• It can be criticised as it relies on interviews with the patients. This can lead to a few issues, like the patients may have had difficulties with their speech and communications to explain their symptoms. They may have shown social desirability bias as well.

Question 7

Charles Darwin (1851)

Answer 7

• Focusses on natural selection over time
• Genetic makeup can undergo mutations due to environmental factors
• This can increase the survival chances of the organism and they are likely to reproduce

Question 8

Lea (2005)

Answer 8

• Found that aggression may be genetic
• The warrior gene (MAOA) is found in 33% of males.

Question 9

Strengths of the Evolutionary approach

Answer 9

• Supported by the nature side of the nature vs nurture debate. Our biology and interactions with the environment have a direct effect on our behaviour
• Supported by the studies of Darwin and the survival of the fittest
• Has advantages as it involved species competing with each other for mating and this maximises the chances of the healthiest offspring who can pass their genes to the next generation

Question 10

Weaknesses of the Evolutionary approach

Answer 10

• Does not clearly explain why some behaviours are adaptive, like OCD, which is found to be genetic, but it does not clearly explain how this aids the survival of the fittest.
• Fails to take into account behavioural and cognitive explanations. It does not take into account free will, and that all species have the free will to make decisions like to reproduce.

Question 11

Buss (1989)

Answer 11

• Investigated what males and females looked for in a long term partner
• 10,000 participants used across 37 cultures
• They had to rate 18 characteristics using a 4 point scale,

0=irrelevant
3=indispensable

Findings found that females desired men with good finances, resources and ambitions

Males desired females who had reproductive value and were fertile, and they wanted women who were youthful and younger than them

Supports evolutionary explanation for partner preferences

Question 12

Strengths of Buss (1989)

Answer 12

It has cross cultural validity, as it spans 37 cultures and it found these results generally across these.

Question 13

Weaknesses of Buss

Answer 13

• Buller (2005) criticised the idea that women universally prefer higher status men with good financial resources. Many women in today’s society have their own independence and do not look to a male for financial support. Lacks temporal validity
• It does not take into account the social and cultural pressures that factor in a choice of partner. Different cultures have different perspectives of what is a suitable partner