The Role of Neural and Hormonal Mechanisms in Human Aggression

935 Words4 Pages
Discuss the role of neural and hormonal mechanisms in human aggression. The relationship between biological mechanisms and aggressive behaviour is a complex one. Some research points to the biological make-up of an individual, such as hormones and neurotransmitters rather than environmental influences. Neurotransmitters are chemicals that enable impulses within the brain to be transmitted from one area of the brain to another. The two main neurotransmitters found to be linked to aggressive behaviour are serotonin and dopamine. High levels of serotonin are said to reduce aggression by inhibiting responses to emotional stimuli that might otherwise lead to aggressive behaviour. Low levels are associated with an increase in impulsive behaviour, aggression and even violent suicide. Evidence supporting the importance of serotonin in aggressive behaviour was found in research using vervet monkeys. Raleigh et al (1991) found that if serotonin levels were reduced by altering their diet, there was an increase in aggressive behaviour whereas an increase in serotonin levels resulted in a decrease in aggressive behaviour suggesting the difference in aggression was due to the serotonin levels. Other research demonstrating the link between low levels of serotonin and aggression was done by Bond (2005). He found that antidepressants which increase serotonin levels reduced irritability and impulsive aggression. The link between dopamine and aggressive behaviour is not as well established. However, increased levels of dopamine stimulated by amphetamines have shown an increase in aggression whereas antipsychotic drugs that reduce dopamine levels have been shown to reduce violent behaviour (Lavine and Buitelaar). Interestingly, a study by Couppis and Kennedy (2008) using mice, found that dopamine acts as a positive reinforcer in the response to an aggressive event. This would
Open Document