adoption studies and Heston Flashcards
What are adoption studies?
Looks at the impact of nature on children who are raised by parents who are not their biological parents.
Who are adopted children compared to in adoption studies?
In these studies adopted children are compared to their biological parents and their adoptive parents. The child will share genetic traits with their biological parents and share the same environment as their adoptive parents.
Why are adoption studies used?
Researchers can determine which traits are of genetic influence (nature/biological) and which are environmental influence (nurture)
What does the term concordance rate mean in the context of adoption studies?
Concordance rate refers to the frequency or likelihood that an adopted child shares a specific trait or condition which their biological or adoptive parent.
What would we expect to find in concordance rates if schizophrenia has a genetic component?
We would expect as higher concordance rate for schizophrenia between offspring and their biological parents compared to heir adoptive parents
What are 2 strengths for adoption studies?
They’re a useful way of separating genes from the environment. Means we can assume similarities due to environmental similarities.
They allow for trends in behaviour to be studies. Adoption studies tend to use the longitudinal method, meaning they follow the same group of children over long periods. These trends in behaviour can be linked to genetic influences.
What are two weaknesses for adoption studies?
Lacking in validity. Children tend to be placed in families like their own, so their birth family and adopted family set very closely matched. The adopting environment may be like the environment of birth parents.
It lacks generalisability. Only certain types of families are accepted as adopters of children. Therefore, this would be less representative.
What was the aim of Heston study?
To see how many adopted children of biological mothers with schizophrenia would go on to develop schizophrenia themselves.
What was the sample for Heston?
50 adopted people born between 1915-1945 to schizophrenic mothers.
They were selected if mothers had:
-diagnosed schizophrenia
-no diseases
-put the child up for adoption
-evidence of consistent behaviour with schizophrenia
-the mother and child were separated.
What was the matched group?
50 adopters whose mothers were believed to be mentally healthy.
How were the participants invited to the study?
Researches sent letters to their homes.
Why did the adults have to be interviewed?
To see if they had schizophrenia themselves.
Where were the interviews conducted?
At home - extraneous variable.
What format was used for the interviews?
Standardised interviews, but interviewers followed any promising leads.
What type of questionnaire was used to gather additional information and what dimensions did it cover?
A general medical and environmental questionnaire was used to explore psychosocial dimensions.
Which personality inventory was administered after the interview?
Short form of MMPI Was given after the interviews.
What happened after the interview to find the results?
-Two psychiatrists independently reviewed information on each participant.
-They excluded genetic and institutional data.
-A third researcher made the final evaluation.
-Each participant received a score from 100 to o, indicating increasing psycho-social disability, based on MHSRS.
What was the risk of developing schizophrenia if one parent had it?
10%
What was the rationale of this study?
If there was no genetic influence on schizophrenia,we would expect that none or perhaps one of the people with a biological mother of schizophrenia to go on to develop the condition.
What was the results?
5 of the adults interviewed (1 female,4 males) had been hospitalised for schizophrenia and 3 of these were chronically ill and had been hospitalised for years. The other two were hospitalised and were taking antipsychotic drugs.
This shows the hypothesis of the fact that 10% would develop schizophrenia was right.
What were the results of the control group?
None of the control group developed schizophrenia, indicating the experience of adoption was not a factor in schizophrenia.
What was the diagnosis on schizophrenia based on?
Generally accepted standards.
How was the generalisability of Heston study?
Is was good as they studies people born to schizophrenic mothers and those born to mentally healthy mothers, this is good for comparison.
Some sectors were poor as they were all born in Oregon USA so is not reflective of adoption and schizophrenia in other countries.
How was the reliability of Heston study?
Good as they used MMPI and MHSRS. These are both standardised tests so would have been testing both groups consistently.
