Aggression - Neural and Hormonal mechanisms Flashcards
What is the neural mechanism in aggression and briefly explain what it does.
The limbic system, it’s an area of the brain that helps to coordinate behaviours that satisfy motivational and emotional urges such as fear and aggression
What are the 2 key structures in the limbic system that are associated with aggression
- Amygdala
* Hippocampus
Explain what the amygdala does
It quickly evaluates the emotional importance of sensory information and prompts an appropriate response. If certain areas of the amygdala are stimulated electrically an animal responds with aggression.
Kluver and Bucy found that destruction of the amygdala in a monkey who was dominant in a social group caused it to lose its dominant place in the social group.
Explain what the hippocampus does
It’s responsible for the formation of LTMs and allows animals to compare the conditions of a current threat with similar past experiences. An impaired hippocampal function prevents the nervous system from putting things into a relevant and meaningful context, and so may cause the amygdala to respond inappropriately to sensory stimuli, resulting in aggressive behaviour.
What are the key hormones in the hormonal mechanism in aggression and briefly explain them.
Testosterone - increases in testosterone are related to greater aggressive behaviour as found in animal studies. There is a similar association with humans that comes from studies of prison population. Dolan found a positive correlation between testosterone levels and aggressive behaviours in a sample of 60 male offenders in the UK maximum security hospitals.
Explain the serotonin deficiency hypothesis
Individuals are less able to control impulsive and aggressive behaviours. When the amygdala is stimulated by external events, it becomes more active, causing the person to act on their impulses and making aggression more likely.
Serotonin can also reduce aggression by inhibiting responses to emotional stimuli that might otherwise lead to an aggressive response.
Evaluation of testosterone study (Dolan) criticism
It’s correlational research therefore it doesn’t actually show cause and effect. There could have been other things that caused the increase in the aggression, such as Freud’s that it’s all about the way the child is brought up. As a child they could have been brought up in an aggressive manner, which naturally causes increased aggression as an adult.
Research support for serotonin deficiency hypothesis (strength/ criticism)
Raleighs’ study on vervet monkeys. They were fed on diets high in tryptophan and they showed decreased levels of aggression. However, those fed on diets low in tryptophan exhibited increased aggressive behaviour, suggesting the difference in aggression could be due to there serotonin levels.
However, this research is based on animals so we can’t extrapolate the findings because humans have more complex emotions and have a conscious.
Criticism of the limbic system
The whole of the limbic system suggests that if you have a hippocampus then you will be aggressive it doesn’t take into account a persons’ free will. All the research done on the limbic system is based mainly on men, so there is no research to show the effect of the limbic system in women.
