Genes - Aggression Flashcards
Why are twin studies used in studying aggression?
To see if there is a high concordance rate between Mz twins which might conclude that there is a genetic cause for aggression
What can Mz twins be compared with?
Dz twins as only 50% of their genes are identical allowing us to see if genes or nurture cause aggression. But Mz twins also normally share a more similar environment so aggression may not only be down to shared genes.
Why are adoption studies used when studying aggression?
To see if adopted children from aggressive families become aggressive. See if aggression is nature or nurture.
What does MAOA do?
Is an enzyme which breaks down dopamine, serotonin and noradrenaline.
What happens if there is not enough MAOA?
Levels of dopamine, serotonin and noradrenaline are abnormally high which is associated with high levels of aggression.
What did Burennert et al do?
Studied a Dutch family where the men were often aggressive and violent. E.g arson, attempted rape and exhibitionism
What did Burennert’s study show?
Urine samples showed 3 of the men had a disturbance of monoamine metabolism = a difference in how their bodies were using MAOA - maybe MAOA deficiency
What issue can Burennert’s study be used for?
Psychology as a science = His study is very scientific. Tried as much as possible to be scientific. BUT this family could have a one off variant for MAOA - can’t generalise
What did Miles do?
Meta-analysis of 24 studies
What did Miles’ study find?
- Strong overall genetic effect that many account for up to 50% of the variance in aggression
- Self-reports and parental ratings showed genes and family environment were causes of aggression + that family influence decreased later in life while genes influence increased.
- Lab studies showed no evidence for genes BUT a very strong family environment effect
