Brendgen Et Al Flashcards
What was the aim
To see if physically aggressive kids are also socially aggressive and to investigate whether the link is down to genetics or social situation by comparing MZ and DZ twins
What was the sample?
234 pairs of twins taken from the Quebec newborn twin study.
44 sets of MZ male twins, 50 sets of MZ female twins
32 DZ female sets and 67 DZ mixed gender twins
What were the results?
Teachers rated boys as more physically aggressive and girls as socially aggressive.
MZ correlations for physical aggression was twice that of same sex DZ
MZ twin correlations for social aggression were similar to DZ correlations
What questions were the teachers asked?
They were asked to rate students 1-3 on: Tries to make others dislike a child Says bad things or spreads nasty rumours Becomes friends with kids for revenge Gets into fights Physically attacks others Bits, hits and kick others
What were the peers asked to do?
Circle photos of 3 children who: Tells others not to play with a kid Tells mean secrets about others Gets into fights Bites, hits or kicks others
Conclusions?
50-60% of physical aggression can be linked to genes
Genes only account for 20% social aggression
Physical aggression mostly nature
Social mostly nurture
