Brendgen et al (2005) Flashcards
how old were the twins in this study
6
the study was looking at genetic and environmental effects on what
social aggression
3 aims of the study
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 leads to another type
how many twin pairs were in the study
234
how was the data gathered
longitudinally - at 5, 18 , 30 , 48 & 60 months and then again at 6 years
who gave ratings of the twins behaviour
teacher and classmates
what were the statements based on for the teacher ratings
statements from the preschool social behaviour scale & the direct and indirect aggression scales
how many points were in the scale for teacher ratings
3
who were the peer ratings done by
every child in the twins’ classes
how were the peer ratings done
by giving a booklet to each child in the twins’ classes with photos of every child in the class in it
each child had to circle 3 pictures that they thought matched 4 different behaviour descriptions
what was the result for physical aggression
higher correlation between the ratings of MZ twin pairs on physical aggression than between same sex DZ twins
in both the teacher and peer rating scores
physical aggression may lead to social aggression, but not the other way around
what were the results for social aggression
scores for social aggression equally correlated MZ and DZ twin pairs
what was the correlation between physical and social aggression explained by
best explained by genes, rather than the environment
what were the 3 conclusions
strong genetic component to physical aggression, but not social aggression
physically aggressive children were more likely to display social aggression, probably due to an interaction between the genes and environment
children tend to become more socially aggressive because of social conventions on physical violence and developing different ways to express themselves
high generalisability
good sample size
generalisation possible to target group of children
low generalisability
high dropout rate
ethnocentric (Quebec, Canada) and only children up to age 6 - not representitive of older children or those who are from different cultures
high reliability
standardised scoring system - procedure can be repeated in samples in different locations or those of different ages to test for consistency
good application to real life
might be possible to challenge social aggression in young children and reduce it - by teaching them to share or include others in play
high validity
two different sources to measure aggression (teacher and peer ratings) - helps to highlight or eliminate bias - teachers and students in agreement
low validity
twins judged to be MZ or DZ with visual checks, only some were DNA tested - means that they may not have been correctly identified - this info may not be correct, this needs to be investigated by moi
high ethics
88 dropped out - right to withdraw
mothers knew children were in the study - parental consent
no situations manipulated - unlikely to be any psychological discomfort
low ethics
socially sensitive research - children must remain anonymous and be free from any labels given during the study
low reliability
extraneous variables - researchers were not able to control them as it was a longitudinal study
