THE BIOLOGICAL APPROACH - KEY STUDIES Flashcards
What was the aim of Raine et al’s study?
To investigate the brain activity in the prefrontal cortex and amygdala of murderers who pleaded guilty for reasons of insanity compared to non-murderers
What was the procedure of Raine et al’s study?
41 participants guilty of murder who had a variety of schizophrenia, brain damage, drug addictions and personality disorders, matched with a control group
The participants stopped taking any medication two weeks prior to the study
The control group were screened for a history of seizures, head trauma etc
They were given PET scans whilst doing visual tasks, after injecting the participants with a radioactive trace that attaches to glucose and allows the researchers to see which parts of the brain are more active (using more glucose)
The murders showed lower levels of activity in the hippocampus (amygdala), prefrontal cortex and parietal lobe compared to the control group, meaning the murders had less emotional responses and rationality/impulse control
What are strengths of Raine et al’s study?
The participants had to stop taking medication two weeks prior to the study which ensured they didn’t affect the brain scans, making it more valid as the scan results were showing their actual brain activity
PET scans give a detailed and live image of the brain making the procedure more valid, objective and scientifically credible
The control group were screened for any brain injuries ensuring they provided a good baseline comparison making it more valid as could compare the brains of the murderers, showing the difference in their brain activity and how this could lead to their aggression
Quite a large sample when there’s a such a small population making it more generalisable
What are the weaknesses of Raine et al’s study?
Brains scans were less developed and they used ‘brain landmarks’ which aren’t the same for everyone, making it less reliable and valid as may not be looking a the right part of the brain
Low ecological validity as doesn’t show the brain activity in real life situations
Only looked at murderers, therefore the results cannot be applied to different forms of aggression making it less generalisable
What was the aim of Brendgen et al’s study?
To investigate the causes of social aggression, particularly the contribution of genes
What was the procedure of Brendgen et al’s study?
234 pairs of both MZ and DZ twins from Quebec Twin Study Centre
The data was gathered longitudinally in April
Consisted of two ratings of the twins’ behaviour:
One by their teacher using the preschool social behaviour scale
The other by their peers where they circled their class at they thought best fit an adjective
The researchers had the parent’s background information including sociology-economic status, marital status, educational background and age
There were no gender differences found in aggression
Social aggression wasn’t different for MZ and DZ twins, suggesting it’s not biological, but physical aggression was higher for MZ twins than DZ twins suggesting it is biological
What are strengths of Brendgen et al’s study?
The fact they used two ratings increased inter-rater reliability and a more accurate rating of their aggression making it more valid
The preschool social behaviour scale is a widely used way of rating aggression so increases objectivity and reliability, as could be used if the study was replicated
The fact the researchers had the parent’s background information told them of any confounding variables (reasons for aggression other than biology) isolating genes as a factor
What are the weaknesses of Brendgen et al’s study?
The sample was only of 6 year olds, decreasing generalisability as can’t apply results to adults, and they were all from Quebec meaning can’t be generalised to other cultures
Social aggression doesn’t develop until 8 years old so doesn’t show a true representation of aggression, decreasing validity
What was the aim of the biological practical?
To investigate whether height and aggression are linked
What was the procedure of the biological practical?
Opportunity sample of ten 17-18 year olds of both genders
The participants completed the Buss Perry Aggression Quiz in a classroom setting for 10 minutes
We also measured their height and then calculated the Spearman rank correlation coefficient to find if it was a statistically significant result
Operationalised height as tall/short using averages
The spearman rank for physical aggression was 0.339 and for verbal aggression it was 0.476, showing there was more of a link between height and verbal aggression
What are strengths of the biological practical?
The operationalisation of height and using the widely known Buss Perry Aggression Quiz increases objectivity and reliability
All the participants were in the same environment when completing the quiz increasing reliability as they all had the same experience (no researcher effect)
What are weaknesses of the biological practical?
The sample only contained 17-18 year olds making the results less generalisable as doesn’t show the aggression of adults (prefrontal cortex doesn’t fully develop until 20s)
The questions in the quiz could have been understood differently by each participant, making the results less reliable
