Brendgen et al

Question 1

What is the aim of Brendgen at al study?

Answer 1

Investigated aggression in MZ and DZ twins
- The extent to which soical and physical aggression are explained by genetic and environmental influences (shared and non shared)
- Whether the overlap between social and physical aggression is explained by the direct effect of one type of aggression on the other

Question 2

How many pairs of twins were used in Brendgen at al study?

Answer 2

234 pairs from Quebec Newborn Twin study

Question 3

What were the teacher ratings on in Brendgen at al study?

Answer 3

Social and Physical aggression of each child on a three point scale (never, sometimes, often)
Social- says bad things, spreads rumours
Physical- hits, bites or kicks

Question 4

What were the peer ratings on in Brendgen at al study?

Answer 4

There were two options for both social and physical aggression
Social- Tells others not to play with a child or Tells mean secrets about another chile
Physical- Gets into fights or hits, bites and kicks others

Question 5

Did having 100% shared genetics lead to more physical or social aggression?

Answer 5

Physical
Only 20%-23% of social aggression was explained by gentic factors