brendgen - contemporary

Question 1

aim?

Answer 1

can social aggression be explained by genetic, shared environment or non shared environment factors?
is there a relationship between physical and social aggression?

Question 2

sample?

Answer 2

• 322 twin pairs from Quebec
• 234 completed full study and physical resemblance was used to identify them as MZ or DZ
• followed from birth at 5,18,30,48 and 60 months

Question 3

procedure?

Answer 3

-took place over 409 classrooms
-teachers rated the level of students physical and social aggression
- children asked to circle pictures of pupils who best fit descriptions like ‘gets into fights’

Question 4

results?

Answer 4

correlation between social and physical aggression in twins was down to genetics rather than shared environment

Question 5

conclusion?

Answer 5

social aggression - 20% genes 60% non shared environment
physical aggression - 50-60% genes and rest non shared environment