Discuss the role of neural and hormonal mechanisms in human aggression
It has been shown that impulsive behavior and aggression have been associated with having low levels of serotonin. Evidence for the role of serotonin comes from the use of drugs that raise levels of serotonin in the brain, such as antidepressants. In clinical studies, antidepressant drugs which increase serotonin levels also tend to reduce irritability and impulsive aggression. This suggests that increased serotonin levels do lead to reduced aggression.
Mann et all gave 35 healthy subjects dexfenfluramine, a drug which is known to deplete serotonin. Using a questionnaire which looked at hostility and aggression levels it was found that treatment with this drug was associated with higher scores in hostility and aggression in males.
There appears to be a link between the neurotransmitter dopamine and aggression, increased dopamine levels can produce increased levels of aggressive behaviour. For example, the increased rates of aggressive behaviour found in the schizophrenic population are believed to be due to the raised levels of dopamine in the brain.
Research by Couppis and Kennedy found dopamine may be a consequence of aggressive behaviour rather than a cause. They suggest that people may seek out aggressive encounters because dopamine is released as a positive reinforcer whenever they engage in aggressive behaviour.
A meta-analysis of studies that had examined neurotransmitter levels in antisocial children and adults found lower levels in those individuals described as 'aggressive' but no difference in dopamine levels for these individuals when compared to 'normal' individuals.
The male sex hormone testosterone is produced in the male testes and in the adrenal cortex. It is thought to increase levels of aggression from young adulthood onwards. It is thought that testosterone may influence areas of the brain that control behavioural reactions, such as the amygdala and the hypothalamus. Testosterone influences the levels of other hormones which are
Mann et all gave 35 healthy subjects dexfenfluramine, a drug which is known to deplete serotonin. Using a questionnaire which looked at hostility and aggression levels it was found that treatment with this drug was associated with higher scores in hostility and aggression in males.
There appears to be a link between the neurotransmitter dopamine and aggression, increased dopamine levels can produce increased levels of aggressive behaviour. For example, the increased rates of aggressive behaviour found in the schizophrenic population are believed to be due to the raised levels of dopamine in the brain.
Research by Couppis and Kennedy found dopamine may be a consequence of aggressive behaviour rather than a cause. They suggest that people may seek out aggressive encounters because dopamine is released as a positive reinforcer whenever they engage in aggressive behaviour.
A meta-analysis of studies that had examined neurotransmitter levels in antisocial children and adults found lower levels in those individuals described as 'aggressive' but no difference in dopamine levels for these individuals when compared to 'normal' individuals.
The male sex hormone testosterone is produced in the male testes and in the adrenal cortex. It is thought to increase levels of aggression from young adulthood onwards. It is thought that testosterone may influence areas of the brain that control behavioural reactions, such as the amygdala and the hypothalamus. Testosterone influences the levels of other hormones which are