BIOLOGICAL KEY STUDIES Flashcards
Outline the aim of raine’s (1997) study
To investigate patterns of brain activity
in murderers who pleaded not guilty by insanity
compared to a matched sample of non-murderers
using pet scans
Outline the sample of raine’s (1997) study
Murders average age 34.3, 39 men 2 women
23 brain damaged, 6 schizophrenics, 3 substance abusers…
Outline the matched pairs sample of raine’s (1997) study
Non-murderers average age 31.7 matched by sex, age and schizophrenia
Outline the design of raine’s (1997) study
Matched pairs by sex, age, schizophrenia (6 in each group) 41 murderers, 41 controls
Outline the variables of raine’s (1997) study
IV; is the participant a murderer who pleaded guilty by insanity or not
DV; the measures of brain activity and structure in PET scans
Outline the method of raine’s (1997) study
- Each participant carried out a practice test
- 10 minutes later a FDG trace was injected
- The ppt then completed a continuous performance task and target recognition was recorded
- After 32 minutes, the participant was PET scanned
Outline the results of raine’s (1997) study
Murderers had lower glucose metabolism in some prefrontal areas
Murderers had less activity in the corpus callosum
Murderers had different levels of activity in the amygdala (more in right, less in left)
Outline the controls of raine’s (1997) study
Six murderers left handed found no effect in results
Head injury differed only in lowered corpus callosum activity
14 non-white murderers compared no different to white
Outline the conclusion of raine’s (1997) study
Violence has a biological cause
But cannot conclude they are the only factor of a predisposition of an environmental trigger
Outline 3 strength’s of raine’s (1997) study
Supporting evidence found similar results
- Narabyashi (1972), Mark & Ervin (1970) Swantje (2012) found similar results in amygdala
Scientific - PET Scans have no experimenter bias and are value free
Useful in leading to appropriate sentencing of murderers
Controls showed no difference
Matched pairs makes generalisable?
Outline 3 weaknesses of raine’s (1997) study
Other factors are unaccounted for
- genetics, hormonal, neurotransmitters, environmental triggers
Reductionist
Deterministic
Matched pairs weren’t perfectly matched
Outline the aim of Brendgen’s (2005) study
To examine the genetic and environmental effects
on social and physical aggression
using 6 year old twins
Outline the sample of Brendgen’s (2005) study
234 twins of 6 years
From Quebec
84% European decent
Outline the variables of Brendgen’s (2005) study
IV; Same class room or different classroom DV; Levels of social and physical aggression
Outline the method of Brendgen’s (2005) study
Children’s physical and social aggression was rated by a teacher and peers
Teachers rated children based on a 3 point scale
Peers were shown photos and asked which three best fit descripitons
Outline the results of Brendgen’s (2005) study
82% received at least one nomination as among the top 3 most socially aggressive in the class
62% received at least one nomination for the most physically aggressive in the class
Both found boys more physically aggressive
Teachers found girls more socially aggressive but peers found boys
Outline the conclusion of Brendgen’s (2005) study
Environmental conditions interact with genetic factors suggesting aggression and violent interaction are an interplay between the two
Young children are capable of using complex manipulative strategies in addition ti physical means to harm their peers
Outline 3 strengths of Brendgen’s (2005) study (TO BE COMPLETED)
First to examine nature vs nurture
Reliability increased by using both teachers and peers
Outline 3 weaknesses of Brendgen’s (2005) study
Small sample size Cannot generalise results beyond 6 year olds 3 is not a large scale Self report Can 6 year olds judge aggression?
Outline the aim of Kety’s study
To find out if there is a genetic bases for schizophrenia based upon genetic relatives and biological relatives in an adoption study
Outline the sample of Kety’s study
34 schizophrenic patients from Copenhagen aged 20-43
33 mentally healthy controls matched by age, gender, age of adoption, and social class of the family
Outline the design of Kety’s study
Natural experiment
Independent groups design
Outline the variables of Kety’s study
IV; Schizophrenia sufferer or control group
DV; The prevalence of schizophrenia related mental illness among family members
Outline the method of Kety’s study
Adoption records used to locate relatives of adoptive children
463 relatives assessed by 4 psychiatrists for schizophrenia in a blind test
The results were then filed into adoptive relative and biological relatives and compared to the ppt
Uncertain diagnosis were removed
Outline the results of Kety’s study
- 7% of bioliogcal relatives displayed schizophrenia in the schizophrenic group
- 9% had this for the control
Outline the conclusion of Kety’s study
There seems to be a genetic component to schizophrenia
Schizophrenic adoptees were more likely to have schizophrenia in their biological families than adoptive
Their biological families were more likely to have schizophrenia than that of the controls
Outline 3 strengths of Kety’s study
Can be generalised to Europe? Fairly large sample size
Reliable and replicable procedure
Test-re-test reliability
inter-rater reliability
Schizophrenic children can be guided away from lifestyles that may worsen their schizophrenia
Outline 3 weaknesses of Kety’s study
Cant generalise outside of Denmark
Only 20-40 year olds
Diagnostic categories were vague
Subjective
Vague concept of spectrum of schizophrenia
Environmental or personal history not accounted for
Participants not approached (unethical)
