Brendgen Et Al Flashcards
3.1.6 The role of hormones (e.g. testosterone) to explain human behaviour such as aggression.
What was the aim of Brengden et al?
To investigate whether physical aggression is caused by nature or nurture.
What was the sample size of brendgen et al?
234 twin pairs from Quebec
94 MZ
140 DZ
What was the procedure of brendgen et al?
Behaviour ratings:
(physical and social aggression score)
From 2 sources who knew the twins well (teacher and classmates) from the age of 5 months to 6 years old.
Teachers:
Three-point scale in responses to statements.
‘sometimes’, ‘never’, ‘often’
Peers:
Matching photographs to description.
‘Tells mean secrets’ + ‘Hits people’
What were the findings of brendgens study?
In both teacher and peer rating scores higher concordance rates for physical aggression was found in MZ twins compared to DZ twins suggesting physical aggression is a consequence of genetics. Similar concordance rates were found for social aggression between MZ and DZ twins suggesting social aggression is a consequence of environmental factors.
What were the conclusions of Brendgens study?
Physical aggression has a strong biological component, whereas social aggression is a consequence of environmental factors.
Evaluate G of brendgen et al?
A large sample of 234 twin pairs meant anomalies would not affect the data making the sample representative. However it’s worth noting that 88 twin pairs disappeared from the Québec newborn twins study before the age of six. (Sample attrition)
Evaluate R of brendgen et al
Used established questionnaires to measure aggression these can be easily replicated making the study reliable.
Evaluate A of Brendgen et al
If social aggression is strongly linked to the environment it must be possible to reduce the worse effects of verbal bullying by children by using early intervention. Classes and workshops may help children to help learn less aggressive ways of interacting
Evaluate V of brendgen eg al
Twin studies are valid way of studying nature versus nurture since MZ twins share 100% DNA but DZ twins share 50%. However these conclusions are never certain and correlations do not prove causation. An MZ twin Maybe stereotype based on the other twins behaviour.
Evaluate E of brendgen et al
The parents of the twins agreed for the children to be in the study giving presumptive consent. The study gets children to look at pictures of their classmates and judge them meaning it may have an impact on their friendships and lead to hurt feelings going against social responsibility.
