2. Methodology/How Science Works d)Describe and evaluate two research methods used in the study of schizophrenia, including one study for each of the two research methods to illustrate the use of the relevant method.
• Suitable examples:
• twin studies

• What is the logic behind conducting twin
studies when investigating schizophrenia?
• What is the logic behind conducting adoption
studies when investigating schizophrenia?
• What do we mean by concordance rate?

The probability of one twin having the disorder if the other already has it - expressed as a percentage.

• Describe use of twin studies to investigate schizophrenia – why are they used?
• Evaluate use of twin studies – are they effective/useful? Why? Why not?
• Use one study to demonstrate method – e.g.
Gottesman and Shields (1966)

Nature V Nurture

• MZ = Monozygotic
 Come from one egg
 Identical twins – share 100% of their genes
• DZ = Dizygotic
 Come from two eggs
 Non-identical twins – share 50% of their genes
Why do we look at both MZ and DZ twins?

Feature
MZ concordance is significantly higher than DZ concordance
Interpretation
MZ concordance is same or similar to DZ concordance
MZ concordance is 100%
MZ concordance is significantly less than 100%

• Read through the project essay
• Use post-it notes to edit the piece if/where possible
• Write an abstract (small summary of the paper)

• Complete the worksheet to recap the
Gottesman and Shields (1966) study
• Look at the evaluation points of the study, decide on strengths and weaknesses

• What are the strengths?
• What are the weaknesses?
• Factors to consider:
- Will twins have identical experiences/environments?
- Will MZ twins be treated the same as DZ twins?

• What should concordance be for MZ twins if genetics was the only explanation?
• Is there another explanation for high concordance amongst family members, particularly identical twins?
• What about those people diagnosed with the disorder but who have no relatives suffering from it?
• Are the concordance rates for twin studies similar?
• Why is concordance for MZ twins always higher than that for
DZ twins?
• If diagnostic criteria has changed over time how will it affect the research findings?

1. Describe one research method used in the study of schizophrenia (4)
2. Evaluate one research method used in the study of schizophrenia (6)
3. Describe one study as an example of this research method
(6)
4. Evaluate one study as an example of this research method
(6)

Describe one research method used in the study of schizophrenia
 Twin studies (mark scheme June 2010)
• When an identical twin is diagnosed with schizophrenia the other twin is studied to measure the frequency with which both of them get schizophrenia
• This is compared with the incidence of both of a pair of non-identical twins getting schizophrenia
• This is because while twins reared together will share the same environment only identical twins share the same genes
• Twins are genetically tested to ensure they are identical
• Researchers will use hospital records to identify the first individual of the pair to be diagnosed

5. Twin sisters Zara and Elizabeth shared everything as they were growing up - dolls, secrets, boyfriends, etc. Recently, Zara has been diagnosed with schizophrenia and now Elizabeth is terrified that she’ll be next.
• Use psychological concepts, theory and studies to discuss whether Elizabeth is right to be worried (8)