BIOLOGICAL Heston's adoption study

Question 1

why are adoption studies used

Answer 1

to find out whether nature or nurture is the leading cause of behaviour

Question 2

what is the concordance rate

Answer 2

the probability that a pair of individuals will both have a certain characteristic, given that one of the pairs has the characteristic

Question 3

what is the aim of the study

Answer 3

• to investigate whether nature or nurture was responsible for the development of schizophrenia

Question 4

when did the study take place

Answer 4

1966

Question 5

what was the sample

Answer 5

• schizophrenia mothers born between 1915-1945
• American Psychiatric hospital
• initially 74 children - 16 were dropped due to death or contact with mothers
• 58 participants mathed with sex, length of time in childcare
• 47 experimental, 50 control

Question 6

what was the procedure

Answer 6

• data collected by school reports, psychiatric hospital reports, interviews and personality inventory
• evaluations made by two psychiatrists and Heston
• schizophrenia given if all three raters agreed
• score 1-100 was assigned regarding psychosocial disability (below 75 = troublesome)

Question 7

what were the results

Answer 7

• differences in psychsocial disability and schizophrenia levels between the control and experimental
• psychosocial scores for born to schizophrenia mothers = 65.2 , control = 80.1
• concordance rate = 10% if one parent had schizophrenia

Question 8

what did Heston conclude

Answer 8

• support the inflluence of genes in schizophrenia
• inheritance contributes to psychosocial disability
• half participants born witih schizophrenia mothers were successful adults with imaginative skills (not found in control)

Question 9

positives of Heston

Answer 9

• internal validity - babies had been seperated from biological mothers from birth - high enviromental control - findings definetly due to genes
• validity - data collected from several sources - qualitative data presented for psychiatrists to make diagnosis
• ethical - natural occuring events - no direct manipulation for measuring genetic basis of schizophrenia

Question 10

negatives of Heston

Answer 10

• lacks population validity - sampling flaws - group of biological mothers may be unrepresetnative of schizophrenic mothers in general - as these schizophrenic mothers gave their child up for adoption
• possibility of selective placement meaning children placed with families similar to birth families - over-estimated nature
• lack of ethics - sensetive nature of data - lead to adopted individuals being stigmatised or treated differently as a result of adoption studies