Brendegen Et Al (contemporary study)

Question 1

In what year did this study take place

Answer 1

2005

Question 2

Aim: what did brendegen want to discover from MZ (identical) and DZ (non-identical)

Answer 2

The extent to which social and physical aggression are explained by genetic and environmental influences

Question 3

Procedure: what design did the researchers use

Answer 3

Twin study design

Question 4

Procedure: how many pairs of twins did they use

Answer 4

234 pairs of twins

Question 5

Procedure: how many MZ male (identical) twins where there

Answer 5

44 pairs

Question 6

Procedure: how many MZ female (identical) where there

Answer 6

50 pairs

Question 7

Procedure: where the DZ pairs used in the final analysis

Answer 7

No

Question 8

Procedure: what happened in the teacher ratings

Answer 8

Teacher was asked to rate physical and social aggression of each hold on a 3 point scale (never,sometimes,often)

Question 9

Procedure: what where the examples of social aggression that where given to the teacher

Answer 9

Says bad things or spread nasty rumours about others

Question 10

Procedure: what where the example of physical aggression that where given to the teacher

Answer 10

Hitting, biting or kicking others

Question 11

Procedure: what where the children asked to do in the peer ratings

Answer 11

They where given a booklet of photographs and asked to match 3 children on that page who best matched a description of behaviour for social and physical aggression they repeated this on the next page and so on

Question 12

Results: what percentage of social aggression was explained by genetic factors by the children and teachers

Answer 12

20% - teachers

23% - children

Question 13

Results: what was physical aggression mostly explained by

Answer 13

Genetic factors

Question 14

Results: what was social aggression mostly explained by

Answer 14

Non-shared environmental factors

Question 15

Results: what did statistical testing show

Answer 15

High physical aggression led to high social aggression but this did not happen the other way around according to teacher and peer ratings