Brendgen et al.

Question 1

What are the two types of social aggression?

Answer 1

Overt - Threatening to withdraw from a friendship

Covert - Spreading a rumour or gossiping

Question 2

What was the aim of the study?

Answer 2

To find out to what extent social aggression is explained by genetics, a shared environment and a non-shared environment

Question 3

What was the sample?

Answer 3

Initially 322 twin pairs however this decreased to 234 twins pairs, all from Montreal

Question 4

At what ages were the twins gathered at?

Answer 4

5, 18, 30, 48 & 60 months and later at age 6

Question 5

What was the procedure regarding the teachers?

Answer 5

• Had to rate the children’s levels of social and physical aggression
• Used a 3 point scale (never, sometimes and often) on different statements (e.g. tries to make others dislike a child)

Question 6

What was the procedure regarding the children?

Answer 6

• Given booklets with childrens faces in

- Had to circle the faces of three children they believed matched the four descriptors

Question 7

What were the four descriptors?

Answer 7

Social aggression:

• Tells others not to play with a child
• Tells mean secrets about another child

Physcial aggression:

• Gets into fights
• Hits, bites or kicks others

Question 8

What were the results (four)?

Answer 8

• 82% of twins received at least one nomination as the most socially aggressive
• 62% of twins received at least one nomination as the most physically aggressive
• Boys were more physically aggressive
• Girls were more socially aggressive

Question 9

Who was more physically aggressive, MZ or DZ twins?

Answer 9

MZ twins

Question 10

Who was more socially aggressive, MZ or DZ twins?

Answer 10

They had similar correlations

Question 11

What three conclusions can be taken from the study?

Answer 11

• Physical aggression is caused by genetics
• Social aggression is caused by the environment
• Physical aggression can lead to social aggression but not the other way round

Question 12

Is the study generalisable?

Answer 12

234 twin pairs were used - large sample size = more representative

All from Quebec - ethnocentric

Question 13

Is the study reliable?

Answer 13

Children and adults rated them - inter-rater reliability

Standardised procedure and 3 point scale - highly reliable

Question 14

Is the study applicable?

Answer 14

Can try to prevent social aggression through good role models

Question 15

Is the study valid?

Answer 15

Yes because:

• Data was gathered from across 409 classrooms - realistic therefore high in ecological validity
• Was a longitudinal study so could see changes in aggression over time

However:

• Results across the classrooms weren’t consistent with one another
• 3 point scale was subjective

Question 16

Is Brendgen ethical?

Answer 16

Remained confidential etc.

Protection from harm - were asked to rate their peers which could have been damaging