3.1 Aggression Flashcards
What is aggression?
An act that is intended to harm another individual physically or psychologically
What is the limbic system?
Subcortical structures in the brain thought to be closely involved in regulating emotional behaviour e.g aggression
Name 3 components of the limbic system
- Hypothalamus
- Amygdala
- Parts of the hippocampus
What is the link between the amygdala and aggression?
The reactivity of the amygdala in humans and mammals is a predictor of aggressive behaviour. The more responsive the amygdala, the more aggressive a person is
Describe Gospic et al (2011) study on the role of the amygdala
- Participants subjected to mild provocation
- When participants acted aggressively fMRI scans showed fast and heightened response by amygdala
- A benzodiazepine drug, which reduces arousal of ANS taken before provocation
- Led to a decreased activity of the amygdala
What are the neural mechanisms in aggression?
- The limbic system
- Orbitofrontal cortex and serotonin
What is serotonin?
A neurotransmitter that has widespread inhibitory effects in the brain
Describe the link between serotonin and aggression?
- Normal serotonin levels linked with reduced firing of neurons which is associated with greater behavioural self control
- Serotonin deficiency in the Orbitofrontal cortex, disrupts the mechanism and leads to impulsiveness (linked with aggression)
What is testosterone?
A hormone from the androgen group that is produced mainly in the male testes (associated with aggressiveness)
What is the link between testosterone and aggression?
Testosterone has a role in regulating social behaviour via its influence on certain areas of the brain implicated in aggression
What did Giammanco et al (2005) find about the role of testosterone?
- Through castration studies on animals, showed that removing the testes reduces the aggression in the males of many species
- Giving injections of testosterone to the same animals restores aggressive bahviour
What did Dolan et al (2001) find about the role of testosterone in aggression?
Found a positive correlation between testosterone levels and aggressive behaviours in a sample of 60 violent offenders
What did Ziomkiewicz et al (2012) find about the role of progesterone in aggression?
Found a negative correlation between progesterone levels and self-reported aggression (suggests low progesterone levels linked to increased aggression in women)
When are progesterone levels lowest (leading to increased aggression)
Levels of progesterone are lowest during and just after menstruation
What are the hormonal mechanisms in aggression?
- Testosterone
- Progesterone