Neural mechanisms in aggression,

Question 1

Neural mechanisms in aggression,
Serotonin:

Answer 1

Serotonin- Under normal circumstances, the neurotransmitter serotonin works on the frontal areas of the brain to inhibit the firing of the amygdala, the part of the limbic system in the brain that controls fear, anger and other emotional responses. Consequently, serotonin has a calming influence.

Low levels of serotonin mean that people can’t control their impulsive and aggressive behaviour. Serotonin also regulates the prefrontal cortex; therefore, lower levels of serotonin affect our response to external stimuli, meaning the can’t control their emotions as well and so becomes aggressive easily and can’t control their responses in a ‘normal’ way. They can’t anticipate risk and therefore impulsively engage in aggressive behaviour.

Question 2

Neural mechanisms Evaluation

Answer 2

Mann et al. (1990)

Lindberg et al. (1985)

Question 3

Mann et al. (1990)

Answer 3

Mann et al. (1990) administered the drug dexfenfluramine (which depletes serotonin in the brain) to 35 healthy adults. The researchers then used a questionnaire to assess hostility and aggression levels, which rose following administration of dexfenfluramine amongst males, but interestingly not amongst females. The research by Mann et al. (1990) demonstrates the issue of beta bias that is inherent in neural explanations of aggression and shows that males and females may not be subject to the same physiological factors when explaining aggression.

Question 4

Lindberg et al. (1985)

Answer 4

Lindberg et al. (1985) compared serotonin levels of 16 male violent criminals with 22 males who had attempted suicide and 39 non-violent males, finding the lowest levels of serotonin by-product 5-HIAA among violent criminals and those who had attempted suicide. This finding indicates that the level of serotonin in the brain negatively correlates with aggression.

-Lindberg’s study suffers from beta bias as the study only includes male participants, and assumes that low serotonin levels will increase aggression in all humans, ignoring the possibility that low serotonin could affect the female brain in a different, perhaps non-aggressive way.