Gottesman twin studies Flashcards
1
Q
describe the aim of this study
A
Gottesman aimed to investigate whether schizophrenia has a genetic basis. (whether it can be passed down in families)
2
Q
describe the procedure of Gottesman’s study
A
- they obtained data from five studies about twins.
-they traced whether, if one twin had schizophrenia, the other also had a similar serious mental health issue - zygosity was measured via:
blood samples
finger-prints - mental health was measured via:
medical records
questionnaires
3
Q
what is zygosity?
A
- Zygosity is a term that describes the degree of similarity of the alleles in an organism
- Zygosity is especially relevant for twins and multiple births, as it indicates whether they are derived from the same or different zygotes
4
Q
describe the findings of Gottesman’s study
A
he found a 75% concordance rate in MZ twins compared to 24% concordance rate in DZ twins for severe schizophrenia
5
Q
conclusion of the study
A
the study strongly suggested that there is at least some genetic basis for schizophrenia
6
Q
give 2 strengths of twin studies
A
- results of twin studies have helped in the prevention of vulnerable disorders such as schizophrenia
- there is high ecological validity as twin studies are natural experiments due to the biological relation in twins
7
Q
give 2 weaknesses of twin studies
A
- twin studies may overestimate genetic influence.
MZ twins have more similar environments than DZ twins they are treated more similarly, spend more time together and tend to share friends. therefore, some of the estimated similarity is actually due to a shared environment - twin studies provide a very broad speculation that a behaviour has a genetic origin, but they cannot identify the specific genes involved
- earlier twin studies such as Lange 1929, were inadequately controlled and lacked validity as to whether the twins were monozygotic or dizygotic as it was based on appearance and not DNA
