Neural and Hormonal Explanations for Aggression Flashcards
What is the limbic system?
A series of subcortical structures in the brain that are associated with emotion.
What is the role of serotonin?
A neurotransmitter, with inhibitory effect, that regulates self-control.
What is the role of testosterone?
A hormone from the androgen group associated with development in males and aggression in both males and females.
Which part of the limbic system is of particular importance when it comes to aggression? Who identified this?
The amygdala. Identified by James Papaez in 1937.
What did Gospic (2011) find?
- Conducted the ‘ultimate game’
- Proposer (pps) offered to split the money with a responder (confederate), if they accept, they both receive money. If they reject, no one receives money.
- fMRI scans identified a heightened response from the amygdala when the responder rejected.
What did Gospic find regarding the potential use of drug therapy in treating aggression?
When given benzodiazepine (to reduce activity in the ANS) before the study, participants showed a reduction in amygdala activity - demonstrating the potential use of drugs to reduce aggression.
Describe the relationship between serotonin and aggression.
A reduction in serotonin levels reduces the ability to control behaviour, thus leading to more impulsive behaviour.
Give some evidence that supports the role of serotonin in aggression.
- Virkkunen et al. - cerebrospinal fluid, taken from violet offenders, had a lower than average serotonin level - of course, only correlational though.
- Chen et al. - mice with a mutation causing a reduction in serotonin release behaved more aggressively.
What did Berman et al. find regarding the use of drug therapy to increase serotonin.
Participants who had received a drug to increase serotonin were more likely to give less severe electric shocks in response to provocation than those on a placebo.
Outline Brunner’s 1993 study.
- A family with a mutation of the MAO-A gene were studied
- This mutation would have caused a lack of enzyme to break down serotonin which should reduce aggression.
- However, the family were highly aggressive and anti-social.
Suggesting there may be a cause other than biology.
What did Wagner et al. find?
Castrated mice were less aggressive than those who were ‘intact’. And mice that received testosterone injections were more aggressive.
What did Dolan study and find?
Studied 60 male offenders in maximum security hospitals. He identified a positive correlation between aggression levels and testosterone levels.
What is the reciprocal model of testosterone?
Claims that testosterone levels vary in relation to the individual’s dominance. Mazur et al - 2100 army veterans - testosterone decreased when married and increased when divorced.
Outline Pope et al.’s study.
Administered testosterone to one group and a placebo to another. Those who were administered testosterone were more aggressive over the 6 week period than those on the placebo.
Give two advantages of the biological explanation of aggression.
Advantages:
- Supporting evidence for the role of the amygdala - Gospic et al. - ‘Ultimate Game’ - fMRI scans showed heightened response when pps were declined and unable to gain money - no causation - lab study -low mundane realism.
- Supporting evidence for the role of neurotransmitters - Mehta and Joseph - 73% of losers, whose testosterone levels rose, re-challenged their opponent - 22% of losers whose levels fell re-challenged their opponent- artificial stimuli - low mundane realism.
