Linnoila & Virkkunen (1992) Serotonin The neurotransmitter serotonin is involved in communication of impulses between neurons. It has widespread inhibitory effects on the brain. Normal levels of serotonin in the orbitofrontal cortex are linked with reduced firing of neurons and this is associated with a greater degree of behavioural self control. Therefore, in relation to serotonin, what could cause aggressive behavior? Therefore, decreased serotonin may disturb this mechanism, reducing self control and leading to an increase in impulsive behaviour, including aggression. Linnoila & Virkkunen (1992) Studied the serotonin levels of impulsive, alcoholic individuals Found that those with reduced levels had a lower thereshold for impulsive and aggressive behaviour Davidson et al (2000) Studied a group of 500 violent individuals Discovered that a large number had a genetic deficit, which caused disruption to the brain's serotonin levels Lenard (2008) Looked at the serotonin levels of 49 monkeys Noted that those with low levels were more likely to take part in dangerous activites and die young, whilst those with higher levels spent more time grooming others and stayed close to the other monkeys

Describe the function of serotonin in relation to aggression. + Further support for the importance of serotonin in aggression is found when looking at individuals who are treated for impulsiveness with a class of drug called selective serotonin reuptake inhibitors, or SSRIs, which help increase serotonin levels. Research carried out by Greenwald et al (1986) and Miczek et al (2002) has found that treating individuals with aggressive impulses using SSRI’s reduced their aggressive behaviour. Outline one ethical issue that might arise when studying individuals who display aggressive behaviour (2 marks) Describe the function of serotonin in relation to aggression. (2 marks) Analysing serotonin levels in the brain requires precise and scientific measurements. Explain how this lends support for the neural and hormonal mechanisms in aggression Socially sensitive research = q1 (2 marks) Briefly outline how research supports the role of serotonin in aggression (2 marks)