Please enable JavaScript.
Coggle requires JavaScript to display documents.
neural and hormonal mechanisms in agression - Coggle Diagram
neural and hormonal mechanisms in agression
the limbic system
set of brain structures that coordinate many of our emotions and motivations particularly those related to survival such as fear/agression
amygdala
plays key role in how we assess/respond to environmental threats
quickly evaluates importance of sensory information and promotes an appropriate response
43/51 patients whose amygdala was destroyed through psychosurgery showed reduced agression afterwards
hippocampus
involved with formation of long-term memories and allows individuals to compare conditions of a present threat with similar past experiences
Impaired hippocampal functioning may cause the amygdala to respond inappropriately to social situations, as the event is recognised as a threatening event, even when it isn’t. This misinterpretation of the event can result in aggressive behaviour
evaluation
strength-study of murders who pleaded guilty by reason of insanity provides support and found there was less activity on the left hemisphere and more on the right in the amygdala and hippocampus meaning deficits in limbic system contribute to aggressive behaviour
limitation- research correlational so no way to show cause and effect and means brain abnormalities could be a cause of aggression or the effect of being aggressive, suggesting further investigation is required.
serotonin
seretonin deficiency hypothesis
makes individuals less able to control impulsive and aggressive impulses
low levels of serotonin (particularly in prefrontal cortex) remove calming inhibitory effect which which normal levels of serotonin have
evaluation
strength- supporting evidence that drugs which increase serotonin activity also reduce levels of aggressive behaviour.Berman et al (2009) found that participants who were given a serotonin enhancing drug gave fewer and less intense electric shocks to a confederate compared to the control group that received a placebo.
limitation-Research that shows a correlation between serotonin and aggression risks over simplifying the true mechanisms involved as other factors which influence aggression are overlooked and suggests further investigation is required
testosterone
studies of gender differences find male are typically more aggressive than females- may be due to biological differences such as levels of testosterone
produced by both males and females but males produce 10x more than females
thought to influence aggression due to its action on brain areas involved in controlling aggression
highest levels of testosterone produced in males age 15-25, the group most likely to produce violent crimes
evaluation
support research by Dabbs who measured testosterone in saliva of 692 adult male prisoners and found higher levels in rapists and violent offenders than in burglars and thieves. found same results in women. this adds value to research and shows effects are not androcentric
limitation-evidence in humans is mixed as some research shows hormones other than testosterone are also significantly involved in aggression. Carre and Mehta's dual hormone hypothesis claims high testosterone only leads to aggression when cortisol is low. When cortisol is high testosterone's influence on aggression is blocked.suggests that the combined activity of testosterone and cortisol may be a better predictor of human aggression than testosterone alone.
evaluation
practical application
use of drugs that increase serotonin activities also reduces levels of aggressive behaviour. drugs to raise serotonin levels have been given to juvenile delinquents and unpredictable institutionalised patients with successful outcomes. adds value to research as brings scientists one step closer to possibly preventing violent tendencies in susceptible individuals