Aggression: Neural & Hormonal Influences Flashcards
Limbic system
Coordinates behaviour related to motivation and emotion
contains amygdala and hippocampus
Is the limbic system a neural or hormonal influence on aggression?
Neural
Amygdala
Responsible for emotion and aggression and other adaptive qualities such as fear
Key in aggressive responses; fast responses to imm stressors
Hippocampus
Responsible for memory and mediated aggression
Suitable responses based on previous experiences rather than innate stimuli
Mediated aggression
Aggression that has been thought about
Is serotonin neural or hormonal influence on aggression?
Neural
Serotonin - overall
Low levels of serotonin lead to increased aggressive behaviour
Serotonin inhibits our responses to emotional stimuli
Inhibiting activation of amygdala, inhibits aggressive behaviour
Low levels of serotonin = response to aggression more often because amygdala is more easily actived when stimulated by external events
Role of serotonin
Serotonin inhibits our responses to emotional stimuli
Inhibiting activation of amygdala, inhibits aggressive behaviour
Low levels of serotonin
Low levels of serotonin lead to increased aggressive behaviour
Low levels of serotonin = response to aggression more often because amygdala is more easily actived when stimulated by external events
Is testosterone a neural or hormonal influence on aggression?
Hormonal
Testosterone
Male sex hormone
Increase dominant and agg behaviour
Thought to influence agg from young adulthood as it affects diff areas of brain involved in controlling aggression
Influences other hormone lvls thought to be involved in aggression, such as vasopressin
Vasopressin
Thought to be involved in aggression
Testosterone influences level of vasopressin
A03 limbic System
Kleiver and Bucy (1937)
Kliever and Bucy
If amygdala removed, animals ability to act aggressively and in a dominant role is removed as well
A03: Hippocampus
Raine (2004)
A03: Raine
‘Unsuccessful psychopaths’ (violent criminals had been caught) had an asymmetry in the hippocampi that wasn’t present in the ‘successful psychopaths’ (weren’t caught)
A03: raine SO what?
Suggested impaired ability of hippocampus and amygdala to work together, lead to inappropriate physical and verbal responses
A03 Serotonin
Raleigh
Mann (1990)
Raleigh - procedure
Vervet monkeys fed diets either:
a) high in tryptophan
b) low in tryptophan
A03 Raleigh - findings
Group a) had decreased aggression (due to high serotonin)
Group b) had increased aggression (due to low serotonin)
A03 Raleigh SO what?
Suggests negative cause and effect between serotonin and aggression
A03 Raleigh criticism
Can’t apply to humans
Vervet monkeys have different evolutionary pressures and social environments
Tryptophan
Increases serotonin levels
A03: Mann procedure
Gave 35 healthy pp’s dexfenfluramine (reduces serotonin)
Pp’s filled out questionnaire about hostility
A03 Mann findings
Males who had taken drug (but not females) exhibited greater levels of hostility and aggression after taking the drug
A03 Testosterone
Dabbs
Lindman
A03 Dabbs
Took saliva samples of criminals to test level of testosterone
A03 Dabbs findings
High levels of testosterone in violent criminals
lower levels of testosterone in non-violent crime
A03 Lindman
Found young males he behaved aggressively when drunk and high levels of testosterone than those who didn’t act aggressively
A03. Criticism between link of neural and hormonal influences and aggression
Reductionist
Complexity of human behaviour
Biological explanations insufficient on own to explain many different aspects of human behaviour
E.g. Banduras research: social learning can be a powerful influence on aggressive behaviour of children
