Genetics - Evaluations Flashcards
What did Theilgaard (1984) find in his research on men with the XYY genotype?
The XYY genotype was associated with an increase in height in individuals, but not an increase in aggression.
How did Coccaro et al. (1997) investigate the role of genetics in criminal behaviour?
Coccaro et al. compared concordance rates of criminal behaviour in monozygotic and dizygotic twin pairs.
Results: MZ twin pairs, with 100% identical genes, showed a 50% concordance, while DZ twin pairs, with 50% similar genes, had only a 19% concordance. This supports the role of genetics in aggression.
What did Godar et al. (2014) discover through selective breeding and gene knockout in mice?
By specifically removing the MAOA gene in mice, Godar et al. observed increased aggression and higher serotonin levels. When given fluoxetine to raise serotonin levels, the aggressive behaviour returned to normal.
What did Brunner (1993) find in his study on a family from the Netherlands with high levels of aggression?
Five males in the family had a dysfunctional version of the MAOA gene, contributing to their aggressive behaviour. Females in the family, even if possessing the dysfunctional gene, were not affected due to the presence of a functional MAOA gene on their other X chromosome.
Outline Stuart et al’s (2014) study.
He studied 97 men involved in severe domestic abuse.
Findings: The most violent men had the faulty MAOA gene, engaging in the highest levels of physical and psychological aggression, inflicting severe injuries on their partners.
