Gottesman Flashcards
What study is Gottesman?
TWIN!!
What was the aim?
To investigate whether there’s a genetic base for schizophrenia and look at MZ and DZ concordance rates to see if there’s a difference
How many participants were there?
62 (31 male, 31 female)
How old were the participants?
19-64
How were participants assigned to the conditons?
- Fingerprints and blood testing
- Physical resemblance
How many pairs of twins were there?
- 24 MZ
- 32 DZ
(5 pairs already been at hospital for schizophrenia)
What were the results?
- For severe schizophrenia, concordance rate for MZ twins was 75% compared to 24% of DZ
- 55% of DZ had healthy twin compared to 21% MZ
What can Gottesman & Shields conclude?
- The closer the genetic link, the more likely both twins will be showing schizophrenic symptoms
- Concordance rate was never 100% for MZ twins, therefore suggesting that genetics aren’t the only cause of schizophrenia
- Diathesis - stress model suggests genes predispose schizophrenia however, they need an environmental trigger
How is generalisability increased?
Large sample of 62 participants so representative of target population
How is generalisability decreased?
Many were admitted to hospital after WW2 so their symptoms may be due to traumatic experiences, rather than schizophrenia
How is reliability reduced?
No DNA testing to assign zygosity (only fingerprint testing & physical resemblance) so not accurate
How is reliability increased?
11 small-scale twin studies found similar results
What are the applications of this study?
- Triggers can be avoided if people know what to look out for
- Schizophrenia harmfulness can be reduced if recognised early by doctors
How is validity increased?
Concurrent and construct validity as findings tie in with diathesis-stress model
How is the study ethical?
Informed consent was given by the participants (or teenagers parents)
