Contemporary study - Brendegen Flashcards
Aims - P1, A01
brendgen aimed to see if social aggression is caused by genes or the environment and to explore whether physical and social aggression share the same cause
Sample - P1, A01
322 pairs of 6 year old twins used at the start of the study but only 234 left at the end
44 pairs were MZ males and 50 MZ females
41 were DZ males and 32 DZ females
67 were DZ mixed pairs of twins
Strength of sample - large sample size A03, P1
One strength of Brendgens study is that it was a very large sample size which was used
A sample of 234 pairs of twins was used which means that the results will be representative of other sets of twins as there will have been a large amounts of different background and home lives which these twins have come from so can be generalised to all sets of twins
Therefore, this means that the sample used would have been able to represent twins in all walks of life and across the world
COUNTER ARGUMENT TO Strength of sample - A03, P1
However, this study was carried out only on twins which were aged 6
This means that twins of a different age may not have the same causes of social aggression as when they were 6
Therefore this means that even though a large sample size was used, all of the twins were the same age so the results which are found may not represent twins of all ages
Procedure - P2, A01
The teachers rated the pairs of twins using 2 standardised questionnaires regarding social and physical aggression of each child on a 3-point Likert scale (‘sometimes’, ‘never’, and ‘often’)
The twins peers had to circle three children per page from a book of pictures, they had to circle which picture matched the description of behaviour - description 1 (social aggression). ‘tells others not to play with a child’ and ‘tells mean secrets about another child’ and description 2 (physical aggression). ‘gets into fights’ and ‘hits, bites or ‘kicks’ others’
Weakness of procedure - Subjectivity P2, A03
One weakness of the teachers giving their opinion on the children is that it can be subjective
The different teachers interpretations of the words ‘sometimes’, ‘never’, and ‘often’ on the Likert scale may have been different which can lead to a degree of subjectivity in the results as the aggression levels which they perceived the children to have could have been different when the same rating on the Likert scale was used
Therefore, this means that the teachers rating the children may have given individuals the same score on the Likert scale used but there opinions of what these words meant in terms of aggression were different so could cause the results to lack validity
Results - P3, A01
only 20% (teacher ratings) to 23% (peer ratings) of social aggression was explained by genetic factors
Physical aggression was mostly explained by genetic factors and partly by non-shared environmental influences
social aggression was mostly explained by non-shared environmental factors
moderate but significant correlation was found between physical and social aggression
Conclusions - P3, A01
Social aggression was caused by environments and physical by genetics
Physical aggression may lead to social aggression but not the other way around
the directional relationship between physical and social aggression is explained by developmental processes
Strength of results and conclusions - Application P3, A03
one application of the study is that it could lead to interventions to reduce aggression
given the progression of aggressive behaviour highlighted in the study, interventions hsould focus on preventing or reducing physical aggression in the early years
Brendgen et al also suggested that future studies could identify the factors that smooth or block the ‘path’ from physical to social aggression
therefore, intervention based on this research could disrupt the transformation of physical aggression into social aggression, ultimately reducing both types of aggression
