Adoption Studies

Question 1

What ‘big question’ do adoption studies attempt to answer about a mental health condition?

Answer 1

If it is ‘nature’ or ‘nurture’

Question 2

How is an adoption study carried out?

Answer 2

We find an adopted person with a specific trait and we look at how many of their biological family members (usually parents) and adopted family members also share that trait (and compare those two concordances).
*They look at differences in frequency between groups and may also compare these levels with the baseline level in the population.

Question 3

What is measured in an adoption study?

Answer 3

• Researchers look at the frequency with which a trait occurs in children living with a parent who has that same trait.
• They also look at rates for children of people with that trait who have been adopted into families without that trait.

Question 4

What is our adoption study in biological psychology?

Answer 4

Kety

Question 5

What was the aim of Kety?

Answer 5

Aim: To find out if there is a genetic basis for schizophrenia and to see if there is a higher rate of
schizophrenia-related illness among biological relatives than adoptive relatives.

Question 6

What is the sample of Kety?

Answer 6

34 schizophrenic patients (two of them MZ twins) taken from the Danish Adoption Register for
Copenhagen. They were aged 20-43. These are referred to as ‘index patients’

Control: 33 mentally-healthy Controls were selected from the Danish Adoption Registry. They were
matched to the schizophrenic patients on age, gender, the age at which they were adopted and the social
class of the adoptive family.

Question 7

What groups were the index patients split into in Kety?

Answer 7

• B1 was a group of 16 patients with chronic (long-term) schizophrenia
• B2 was a group of 7 with acute (short-term or one-off) schizophrenia
• B3 was a group of 11 with “borderline schizophrenia” or “latent schizophrenia”

Question 8

What was the independent and dependent variables in Kety?

Answer 8

IV: Schizophrenia sufferers and a Control Group with no history of mental illness.
DV: The researcher’s measured the prevalence of schizophrenia-related mental illness among family
members

Question 9

What is the method of Kety (your adoption study)?

Answer 9

-Danish family records were used to locate adoptive and biological relatives of all the participants (463 relatives used and their mental health status was assessed).
- Using a blind test (the psychiatrists did not know whether the records were from an adoptive or a biological family member) 4 Danish psychiatrists used the medical records to diagnose the family members
-4 Psychiatrists diagnosed the family based on their medical records and classified them as SZ or no and they were then assigned to either ‘adoptive’ or ‘biological’ relative groups once identities were revealed
- In 4 cases, they couldn’t reach a conclusion and these relatives were dropped from the study

Question 10

Give 2 results of Kety

Answer 10

Of 150 biological relatives of index cases;
* 13 (8.7%) had a diagnosis of schizophrenia (or similar)
* Of 156 biological relatives of the controls;
* 3 (1.9%) had a diagnosis of schizophrenia (or similar)

Question 11

What is the conclusion of Kety?

Answer 11

There seems to be a genetic component to schizophrenia. Schizophrenic adoptees were more
likely to have schizophrenia in their biological family than their adoptive family. Their biological families
were more likely to have schizophrenia than the families of Controls

Question 12

Is it a strength or a weakness that adoption studies help us to determine if behaviour is due to nature or nurture and why?

Answer 12

Strength. This is a strength of adoption studies as it is useful in helping us determining why a behaviour may occur in order for us to put support/interventions into place to support a person.

Question 13

Is it a strength or a weakness that adoption studies are naturally occurring and they do not require manipulation of groups from the researcher.

Answer 13

Strength
One strength of adoption studies is that they are considered ethical. This is a strength as adoption is a naturally occurring events that does not require manipulation of groups from the researcher.

Question 14

Why is it a weakness that adopted children need to be identified, followed for a long time and locate and assess each of the family members?

Answer 14

One weakness of adoption studies is that recruitment may take a long time to find children who meet the criteria and match to families. This is a weakness as it becomes time consuming as it may take several years.

Question 15

Why can it be difficult to establish ‘nature vs nurture’ in an adoption study?

Answer 15

One weakness of adoption studies is that it may be difficult to establish what is due to nature or nurture. This is a weakness as the prenatal environment of the children may be different.

Question 16

Why is it a weakness for validity in adoption studies that some children are adopted by people who are the same culture as their biological parents?

Answer 16

One weakness of adoption studies is that it may be difficult to establish what is due to nature or nurture. This is a weakness as adopted children may be adopted by a family culturally similar to their biological one and so may end up with some shared environment.

Question 17

Why is attrition an issue for adoption studies?

Answer 17

One weakness of adoption studies is that there may be attrition (participant drop out). This is a weakness as the results in the adoption studies may not longer be representative.