Brengden AO3

• Is Brendgens study ethical?

  > Did not directly manipulate the children (secondary data), gained parental written consent and the insitutional review board approved

  > Ethically sound
• Why does Brendgens study lose validity?

  > Used secondary data from the longitudinal twin study in Canada for her own research which lowers validity

  > She has no way of personally checking the data which may result in her conclusions being flawed
• How is Brendgens study reliable?

  > Both teachers and peers rated the twins' aggression and there was high level of agreement between their ratings

  > Increases the inter-rather reliability meaning that the findings are consistent
• Why does Brendgens study lose validity?

  > Physical and social aggression are based on memory recall (not actual observations) and thus may not match reality

  > May not be a valid way of measuring
• Why does Brendgens study have high internal validity?

  > Used same sex DZ twins to match with the MZ twins to ensure that they were as similar as possible

  > It acted as a control which increase internal validity
• Why is Brendgens study not generalisable?

  > Data was only collected from six year old Canadian twins

  > generalising beyond this age and cultural group is difficult, social aggression may not have yet developed fully in children of this age