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Neural and Hormonal mechanisms in aggression - Coggle Diagram
Neural and Hormonal mechanisms in aggression
Neural mechanisms
Limbic system
Set of brain structures that helps to coordinate many of our emotions and motivations, particularly those that are related to survival such as fear and aggression
Speed and sensitivity of limbic system responses are important predictors of aggressive behavior in humans
Amygdala and hippocampus
Amygdala
Key role in how we assess and respond to enviromental threats
In aggression as it quickly evaluates the importance of sensory info and promoting an appropriate response
Research found 43/51 patients whose amygdala was destroyed through psychosurgery showed reduced aggression afterwards
Hippocampus
Involved in the formation of long term memories and allows individuals to compare the 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 recognized as a threatening event
Misinterpretation of the event can result in aggressive behavior
A03 of Neural mechanisms
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Correlational, this is an issue as there is no clear way to show cause and effect, e.g murders have already committed when tested so effect cannot be assumed, this matter because is highlights the complexity of the relationship between biology and behaviour and suggests that further investigation is required
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In a study of murders who pleaded not guilty by reason of insanity, provided support by researcher Raine for the role of neural mechanisms, the murders and their controls were injected with a glucose tracer and then completed a 32 minuet continuous performance task that measured sustained attention, he found an imbalance of activity between the left and right hemisphere in the limbic system, less activity on the left and more on the right, this means that his delicts in the limbic system contribute to aggressive behavior and show support for the neural explanation
Serotonin
Normal levels of serotonin have a calming, inhibitory effect on neural firing in the brain as it inhibits responses to emotional stimuli which makes us angry
Low levels particularly in the prefrontal cortex removes this inhibitory effect and makes individuals less able to control impulsive and aggressive responses this is know as serotonin deficiency hypothesis
Virkkenen compared levels of serotonin metabolite in the cerebrospinal fluid of violent impulsive and violent non-impulsive offenders, they found significantly lower levels of the metabolite in the impulsive offenders, this implies disruption of serotonin functioning playing a role in reactive aggression
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Evidence to support role of serotonin in aggression, research shows that drugs that increase serotonin activity also reduces levels of aggressive behaviour, e.g Berman found ppt who were given a serotonin enhancing dug gave fewer and less intense electric shocks to a confederate compared to the control group that received a placebo, only true to ppt who has a prior history of aggressive behaviour however it is evidence of a link between serotonin function and aggression that goes far beyond the usual correlational findings
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Correlational, there are good ethical reasons for this because opportunities to alter neurotransmitter levels are limited, research that shows a correlational between serotonin and aggression risks over simplifying the true mechanisms involves are other factors which influence aggression are overlooked meaning that neural regulation of aggression is certainly more complex than our understanding
Testosterone
Studies of gender differences find ales are typically more aggressive than females, this could be due to biological differences such as levels of testosterone
The hormone is produced by both male and females but is produced 10 times more by males, highest levels of testosterone are produced in ales ages 15-25 and this group most likely to commit violent crimes
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Supporting evidence by Dabbs, he measures testosterone levels in saliva of 692 adult male prisoners and found higher levels in rapists and violent offenders than in thieves, the same effects of testosterone are also found in women where he also tested women and found testosterone was higher in cases of unprovoked violence but lowest where violence had been defensive
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A limitation is that evidence in humans is mixed this is because some research shows hormones other than testosterone are also significantly involved in aggression e.g 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 aggressions blocked suggesting combined activity of testosterone and cortisol may be a better predictor of aggression
A03:
O: neural and hormonal do not account for social and environmental factors that influence aggression, the social learning explanation suggests aggression is learned from role models in the environment, e.g bandura found children who had observed the adult being rewarded behaved most aggressively, this means this explanation is limited and do not provide a complete explanation for aggression
ID: too simplistic