Methodology: Adoption Studies + Heston (1966) Flashcards
Define ‘concordance rate’.
The probability of a relative sharing a certain characteristic as another relative.
What is an adoption study?
Looking at an individual and their genetically related relatives in comparison to adoptive relatives.
Why are adoption studies carried out?
To study whether behaviour is due to nature or nurture.
Describe the results for behaviour being due to nature in an adoption study.
If biological relatives have high concordance rates for a condition compared to adoptive relatives, this suggests that the behaviour studied is due to nature.
Describe the results for behaviour being due to nurture in an adoption study.
If the concordance rate is high in adoptive relatives compared to biological relatives, this suggests that the behaviour being studied is due to nurture.
What methods may an adoption study use?
- DNA sampling
- Questionnaires
- Interviews
- Psychometric testing
List 2 strengths of adoption studies.
1) High reliability due to allowing us to study trends in behaviours via longitudinal methods of following the same group of children for long periods of time
2) High application due to results separating the cause of certain behaviours being due to nature or nurture allowing more focused research
List 3 weaknesses of adoption studies.
1) Low generalisability as the circumstances in which a child will be split up from their parent will be unique and cause different environmental variables for the adopted child that wouldn’t represent a normal child
2) Low validity due to the overemphasis on the role of genes as children tend to be placed in families similar to their own so their birth family and adopted family will match very closely
3) Low ethics due to adoption studies have a high chance of causing disturbance to the family harmony if the adopted child discovers certain things about their biological family
Identify an adoption study.
Heston (1966)
Describe the aim of Heston (1966).
To investigate how many adopted children of biological mothers with schizophrenia would develop schizophrenia themselves.
Describe the procedure of Heston (1966).
- 50 adoptees whose mothers were believed to be mentally healthy were matched for sex, type of adoptive placement, and length of time in care
- Subjects were contacted by letter and asked to participate in an interview to establish whether any of them had gone on to develop SZ
- Nearly all interviews took place in their homes
- The information was evaluated blindly by two psychiatrists, then once again by a third
- A score from 0-100 on psycho-social disability constituted the evaluation
- A control group was used to eliminate possibly that adoption itself was cause for SZ
Describe the results of Heston (1966).
- 10% of adults interviewed whose mother suffered SZ had been hospitalised with SZ
- None of the control group developed SZ
Describe the conclusions of Heston (1966).
- Genetics plays a role in schizophrenia
- With no evidence for the role of the environment on developing SZ
Evaluate the generalisability using a low point.
P - Low
E - Sampling method involved contacting sample by letter asking them to participate
E - Therefore those who responded and agreed share characteristics that would make them likely to take part
Evaluate the reliability using 2 high points.
P - High inter-rater
E - In total 3 researchers confirmed the evaluative assessment of the adoptees and whether they had SZ
E - Therefore it is objective and removes bias with high scientific credibility
P - High
E - The interviews were standardised with the same questions being asked to each ppt
E - The results will be easily comparable and the procedure itself can be replicated