Brendgen et al (2005)

Question 1

how old were the twins in this study

Answer 1

6

Question 2

the study was looking at genetic and environmental effects on what

Answer 2

social aggression

Question 3

3 aims of the study

Answer 3

to see if social aggression could be caused by genes or the environment

to see if social aggression shared the same cause as physical aggression

to see if one type of aggression leads to another type

Question 4

how many twin pairs were in the study

Answer 4

234

Question 5

how was the data gathered

Answer 5

longitudinally - at 5, 18 , 30 , 48 & 60 months and then again at 6 years

Question 6

who gave ratings of the twins behaviour

Answer 6

teacher and classmates

Question 7

what were the statements based on for the teacher ratings

Answer 7

statements from the preschool social behaviour scale & the direct and indirect aggression scales

Question 8

how many points were in the scale for teacher ratings

Answer 8

3

Question 9

who were the peer ratings done by

Answer 9

every child in the twins’ classes

Question 10

how were the peer ratings done

Answer 10

by giving a booklet to each child in the twins’ classes with photos of every child in the class in it

each child had to circle 3 pictures that they thought matched 4 different behaviour descriptions

Question 11

what was the result for physical aggression

Answer 11

higher correlation between the ratings of MZ twin pairs on physical aggression than between same sex DZ twins

in both the teacher and peer rating scores

physical aggression may lead to social aggression, but not the other way around

Question 12

what were the results for social aggression

Answer 12

scores for social aggression equally correlated MZ and DZ twin pairs

Question 13

what was the correlation between physical and social aggression explained by

Answer 13

best explained by genes, rather than the environment

Question 14

what were the 3 conclusions

Answer 14

strong genetic component to physical aggression, but not social aggression

physically aggressive children were more likely to display social aggression, probably due to an interaction between the genes and environment

children tend to become more socially aggressive because of social conventions on physical violence and developing different ways to express themselves

Question 15

high generalisability

Answer 15

good sample size

generalisation possible to target group of children

Question 16

low generalisability

Answer 16

high dropout rate

ethnocentric (Quebec, Canada) and only children up to age 6 - not representitive of older children or those who are from different cultures

Question 17

high reliability

Answer 17

standardised scoring system - procedure can be repeated in samples in different locations or those of different ages to test for consistency

Question 18

good application to real life

Answer 18

might be possible to challenge social aggression in young children and reduce it - by teaching them to share or include others in play

Question 19

high validity

Answer 19

two different sources to measure aggression (teacher and peer ratings) - helps to highlight or eliminate bias - teachers and students in agreement

Question 20

low validity

Answer 20

twins judged to be MZ or DZ with visual checks, only some were DNA tested - means that they may not have been correctly identified

Question 21

high ethics

Answer 21

88 dropped out - right to withdraw

mothers knew children were in the study - parental consent

no situations manipulated - unlikely to be any psychological discomfort

Question 22

low ethics

Answer 22

socially sensitive research - children must remain anonymous and be free from any labels given during the study

Question 23

low reliability

Answer 23

extraneous variables - researchers were not able to control them as it was a longitudinal study