Contemporary study Brendgen et al 2006 Flashcards
Contemporary study Brendgen et al 2005
aim
To see if social aggression could be caused by genes or the environment
To see if social aggression shared the same cause as physical aggression
To see if one type of aggression could lead to another type
Contemporary study Brendgen et al 2005
Generalisability - (twins + quebec)
The sample of the study being both MZ twins and DZ twins with there being 94 MZ twins and 140 DZ twins and 234 pairs of twins alltogether with only 123 pairs of tiwns actually being DNA tested (94% were accurate)
twins were all 6 yrs old
These twins especially NZ twins only make up a very small percentage of the population
meaning they may not represent the population as a whole reducing generalisability
and due to it taking place in Quebec the surveys were done in french and all the participents were candaian so the study was ethnocentric and cannot be applyed to other cultures
Due to these two factors it means that the results of the study that search the question is more likely to be caused by the environment and the physical aggression may lead to social aggression but not the other way around cannot be generalised to the whole population
Contemporary study Brendgen et al 2005
+ test retest reliability
Standardized procedure of the teachers racing the twins social behavior on a 3-point scale(0= never 2=oftern) for 6 statements such as do they get into fights (physical aggression) tries to make other children dislike another child (social aggression)
these scores added together to 2 sepperate ones for teaches SA and PA
And the twins peers circling 3 pictures of students in the in a class that matched 4 different behavior descriptions
for example “tells other children not to play with another child” (social aggression) “gets into fights” (physical aggression)
These behavior descriptions and statements were standardised across the whole study
Means that the study is highly replicatable and has high test retest reliability
Contemporary study Brendgen et al 2005
- internal validity
(statments behaviour descriptions and 3 point scales =subjective + extraneous variables)
The previously mentioned 3-point scale the teachers used has low accuracy and is very subjective as it is based on the teachers opinions on the twins behaviour
and the children could just circle nobody in the booklet who could have believed that if they circled the twins they would get into trouble and so to protect their friends they wouldn’t have circled them showing demand characteristics
These factors are extraneous variables which make it much harder to establish cause and effect effectively and therefore be study has low internal validity as it cannot be certain that the result are valid
Contemporary study Brendgen et al 2005
good ethics (parential concent when born)
The children enter the study when they were born (between November 1995 and July 1998 in quebec, canada) this means they had parental written consent and they would therefore have had a debrief and would have known that they have the right to withdraw the children’s information at any time
This means that there were no BPS ethical guidelines were breached and therefore the study was highly ethical
Contemporary study Brendgen et al 2005
Conclusion + application (change enviroment reduse SA)
It was concluded that social aggression was likely to be due to environmental effects while physical aggression was more likely to be due to genetics therefore did not share the same cause
however it was also discovered that physical aggression would lead to social aggression but this would not happen the other way around
it was also concluded that SA increaced with time as people find more ways to express themselfs
Aplication:
the results of the study may help reduce social aggression when it begins to show developments as we understand that social aggression is due to environmental effects so perhaps by reducing the social aggression in the environment that they are being brought up in then they will show reduction in social aggression themselves
Contemporary study Brendgen et al 2005
Evaluation order
Aim (If SA is genes or enviroment and if its caused by the same thing as PA and if one could lead to another)
Generalisability - (ethnocentric + twins)
reliability + (standardised procedure 6 statments teachers 3 point scale / 4 behaviour descriptions classmates booklet circle)
-Internal validity ( subjective + demand characteristics = invalid)
+ ethics (parential concent)
conclusion (SA = Enviroment,≠ PA = genes PA>SA SA≠PA + SA ^ as express themselfs)
Aplication (Change enviroment reduce developing SA)
contempomary bio Brengden et al 2005
results
Brendgen does a Chi Squared inferential test, comparing the teacher + student ratings of the MZ + DZ twins for physical and social aggression.
The differences were not significant.
Teachers and Students both rated agg simularly showing agreement
There was also a “moderate” correlation between teacher and peer ratings for physical aggression (r=0.25) and for social aggression (r=0.33).
teachers rate boys more PA and girls more SA, but students rate Boys Both more SA and PA
compared corrolation between Teacher and student aggressions for MZ and DZ.
Found MZ same sex twins had 2x more rated PA than DZ same sex twins
so little disagreement about the MZ twins’ physical aggression
but a lot more about the DZ twins.
Maybe cuz DZ twins were more influenced by their surroundings.
The MZ twins’ correlations for social aggression were similar to the DZ twins’ correlations.
suggests SA is less linked to genes
as both types of twins equaly affected by surroundings
unlike PA
brengden et al 2005 contemp bio
implecation application
If social aggression is strongly linked to environment, it must be possible to reduce the worst effects of verbal bullying, gossiping and “trolling” in social media by
children, by using early intervention. Classes and workshops might help children learn less aggressive ways of interacting.
Brengden et al 2005 contemp
conclusion but better :D
So Social aggression is more linked to the environment as both MZ and DZ twins showed similar levels of it
whereas physical aggression is more linked with genetics as same sex MZ twins were rated twice as high in physical aggression correlation between the two twins
than DZ twins as the DZ twins may only have one person show physical aggression whereas the other twin may not
this is because they are not 100% identical DNA like MZ twins
Therefore social aggression is linked with environmental factors while physical aggression is linked with genetic factors
also therefore meaning that they do not share the same cause
also physical aggression can lead to social aggression but not the other way around
and only if the environment encourages the social aggression
she also finds as the children can get older it is predicted that
due to the understanding of social norms towards physical aggression
and finding more ways to express themselves
that there will be a decrease of physical aggression and an increase in social aggression
Brengden et al 2005 bio contemp
Internal valid + ctrls
It was internally valid as the confounding variable
that the children would not know each other and therefore would not be able to accurately circle the students that correctly demonstrated and represented the descriptors
Was avoided
As the children were able to build a rapport with each other over the winter term
as the study purposely took place in the spring term to ensure that the children and teachers had time to know the students well so that the questionnaire and circling task would be able to be completed validly
Therefore this control enabled cause and effect between the type of twin and the results from the questionnaire and circling task were able to be established via the fact that the children and teachers new each other’s behaviour
therefore meaning it is more likely the results are int valid
