Mechanisms in aggression Flashcards
What do biological explanations suggest?
Biological explanations suggest that aggressive behaviour can be in the make-up of an individual rather than in the environment around them
Explain what is meant by a neurotransmitter.
Neurotransmitters are chemicals that enable impulses within the brain to be transmitted from one area of the brain to another. Serotonin and dopamine have been seen to link to aggression. Low levels of serotonin and high levels of dopamine = AGGRESSION
Explain the role of Serotonin in aggression.
- Thought to reduce aggressive behaviour by inhibiting responses to emotional stimuli.
- Low levels = aggressive behaviour/violent suicide/impulsive behaviour
- Mann et al = gave 35 healthy people dexfenfluramine (reduces levels of serotonin). Using questionnaires found that the drug caused MEN to become violent and aggressive.
What did Raleigh find?
Researcher studied monkeys and found that diets with high levels of serotonin decreased their aggressive behaviour.
What did Bond et al find?
Found that drugs which raise serotonin levels tend to reduce impulsive aggression.
What has Larson found?
Found that when comparing violent to non-violent criminals, the levels of serotonin in violent criminals were much lower.
What has Summers et al. suggested?
That serotonin modifies aggression, but it cannot be singularly identified as the only cause of aggressive behaviour due to complexity of human body.
Outline the role of Dopamine.
- High levels of dopamine are linked to aggression.
- Anti-psychotic drugs which reduce dopamine activity in the brain have been shown to reduce aggressive behaviour.
- Couppis et al. = some individuals seek out aggressive encounters because of the rewarding sensations caused by the increase in dopamine.
Outline the research by Ferrari et al.
Made rats fight with each other for 10 days and on the 11th day there was no fighting but instead researchers measured the levels of serotonin and dopamine and found that dopamine levels increased and serotonin levels decreased.
Why is it difficult to effectively research the role of dopamine in aggression?
It is very difficult to effectively research the role of dopamine in aggression and establish a causal link, due to the fact that dopamine is an essential neurotransmitter for many behaviours including the control of movement.
What has Dr. Ingo Vernaleken found?
Found that p’s who behaved the most aggressively had lower levels of dopamine.
Outline the role of testosterone.
- Male sex hormone thought to influence aggression from young adulthood onwards due to its action on the brain areas involved in controlling aggression.
- An androgen produced in the male testes, it is usually released during stage 4 of the sleep cycle.
- Wingfield et al. (The challenge hypothesis) = in monogamous species levels of testosterone should only raise above the baseline breeding level in response to social challenges such as male-male aggression or threat to status.
What has Dabbs et al. found?
Studied salivary testosterone in violent and non-violent criminals. Those with highest testosterone levels had history of primarily violent crime.
What has Harrison found?
Noted that after giving testosterone to 56 men and then having them play a frustration-inducing computer game, aggressive responses increased in most participants.
What has Eisenegger found?
Found that testosterone could make women act ‘nicer’ rather than more aggressively.
