gossiping, spreading rumours, criticising others behind other people
what were Brendgen aims?
to see if social aggression is caused by the environment
to see if social aggression shares the same causes as physical aggression
to see if one type of aggression could cause another
what was the sample size that had data collected on them?
234pairs of twins
how many were identical twin pairs?
94 identical twin pairs
how many twin pairs had DNA tested to check if monozygotic otr dizygotic ?
123 pairs of twins
what were the results of the DNA testing?
94% of the assignments assumed were correct
what were the methods of sorting pairs into monozygotic and dizygotic?
physical resemblance and questionnaires
what does it mean by a longitudinal study?
the study followed all the twin pairs over a long period of time
over what time length was the data on the twins collected ?
6 years
how any classrooms were involved in the experiment?
409 as some twins in separate classes
what did the experimenters use to gather data from teachers and peers?
standardised questionnaires
how did the teachers rate the aggression?
completed questionnaires with scales of 0= never 1=sometimes and 2=often
what was an example for a teacher measuring a twins social aggression?
"triestomakeotherdislike a child"
what was an example for the teachers measuring a twins physical aggression?
"gets into fights"
how did the peers measure the twins aggression?
given photographs and asked to circle the 3 children who fitted the descriptions the most
what was an example of social aggression statement given to the peers?
"tells others not to play with another child"
what was an example of physical aggression statement for peers?
""hits, bites or kicks others"
what ages were the twins when the researcher gathered evidence?
5 months, 18 months, 30 months, 4yrs, 5yrs, 6yrs old
what were the results for physical aggression?
positivecorrelation between MZ twins was much higher than the DZ same sex twins for
what was the conclusion for the physical aggression correlation for MZ and DZ twins
for 6 years old 50-60% of aggression is linked to genes
what were the result for the social aggression?
correlation between MZ twins for social aggression was the same for the DZ twins
what was the conclusion for the social aggression?
only 20% of social aggression is genetic (60%) from non-shared environment
does one type of aggression lead to another type of aggression?
yes, physical aggression can lead to social aggression.
cannot happen the other may around
what was the conclusion for the physical leading to social aggression?
perhaps the children learnt that the physical aggression not socially acceptable and found they coulld get away with social aggression
what was negative about the generalisability of the study?
limited age range of 5 months to 6 years cannot generalise beyond that
twins are not typical of normal siblings- unusual closeness
what was positive about the generalizability?
largesample group of twins and so is representative
what was good about the reliability of the study?
rating scales were standardised and had good internal reliability
what was negative about the reliability?
the scales had to be translated into French for some teachers and peers therefore possible to get things lost in translation
but there was a translator who verified it
what was positive about the validity of the study?
peer and teacher ratings were consistent - reducing bias
what was negative about the validity?
identification of some of the twins were based on the physical appearance and questionnaires alone with no DNA to back it up.
what were the ethics in this study?
informed consent was given by the parents as the children were under 16 years old
the research was found to be socially sensitive research as it has a danger of labelling and creating a self-fulfilling prophecy by identifying a 6 year old as being genetically aggressive