Aggression

Question	Answer
What is serotonin?	It has an inhibitory function on the brain and, in normal quantities, has a calming effect, maintaining a stable mood. EXTRA: Serotonin neurotransmitter that has been linked to aggressive behaviour.
The exact role of serotonin is unclear but how is it thought to work?	Working in the frontal cortex in the brain, inhibiting aggressive activity.
Where is aggressive activity thought to originate from?	• The limbic system. • In particular, the amygdala. EXTRA: Individuals with a low level of serotonin are thought to have less control over their emotional responses, leading to aggression.
Which drug has been found to reduce serotonin levels?	Prozac. "Prozac (fluoxetine) is an antidepressant belonging to the selective serotonin reuptake inhibitor (SSRI) class of drugs."
What side effect does Prozac have?	• Prozac can reduce serotonin levels. • This has been shown to ultimately depress mood and result in increased aggression.
Who's research supports the theories surrounding the effects of serotonin on aggression?	Lindberg.
How was this research conducted?	• Serotonin levels of 16 males convicted of violent crimes (murder), 22 males who had attempted suicide and 39 healthy males were compared. • A by-product of serotonin production (5-HIAA) was found in spinal fluid and measured.
What does low levels of 5-HIAA indicate?	Low levels of serotonin on the brain.
What were the results found in the aforementioned study?	• Lindberg found the lowest levels in those who had killed a partner or attempted suicide. • This finding indicates the level of serotonin in the brain is negatively correlated with aggression: as serotonin levels go down, aggressive behaviour increases.
Define a positive evaluation for theories surrounding serotonin.	There is supporting experimental evidence by Passamonti whom altered the serotonin levels of participants by changing their diet to avoid or contain tryptophan and each were then given a questionnaire to assess tendency to be aggressive as well as experiencing fMRI scans.
What is tryptophan?	A substance needed in the body to produce serotonin.
What were the results of this study?	• When scanned using fMRI, researchers found that those with low amounts of tryptophan and high tendency to be aggressive had low brain activity between the prefrontal cortex and limbic system. • Suggests that low serotonin levels make it difficult for prefrontrol cortex to control aggressive emotion.
Give a negative evaluation (involving issues and debates) for the theories surrounding serotonin.	• This is an example of biological reductionism. • Reduces explanations of aggression to simplistic biological processes. • More complex processes that may be involved in aggressive behaviour such as relationship problems, anxiety due to stressful environments, learnt behaviours from upbringing or even political motivation.
What is the limbic system?	A collection of structures in the centre of the brain.
What is its function?	• To process emotional responses. • It has been identified as being responsible for aggressive behaviour, with the external layer of the brain, the cortex, working to control aggression produced by the limbic system.
The destruction of which area of the limbic system is responsible for producing permanent savage behaviour in cats?	The hypothalamus. Extra: This research was conducted by Bard and Mountcastle.
What is another part of the limbic system involved in the perception of emotions.	The amygdala.
Fill the blanks: Animal studies have shown stimulating the amygdala can cause __________ _________ to the environment. _______ of the amygdala can cause ________ in cats and ________ in humans.	Animal studies have shown stimulating the amygdala can cause aggressive responses to the environment. Removal of the amygdala can cause tameness in cats and calmness in humans.
What is a supporting piece of research for the theories surrounding the limbic system?	• Raine. • Studied if violent criminals have difference in their limbic system. • Used PET scanners to view brains of 41 murderers and 41 controls. • A number of the murderers had abnormalities in the way their limbic system functioned. • Suggests limbic system could be implicated in aggressive behaviour.
Describe a supporting case study surrounding the limbic system.	• Reported by Sumer. • 14 year old behaving aggressively, expressing high levels if anger and rage as well as epileptic fits from age of 3. • MRI scans found tumour in the limbic system and after treatment she returned to normal levels of aggression.
Give a weakness of the limbic system explanation.	• It is an example of biological determinism. • Suggests some individuals are unable to control their aggression in the same way as others due to limbic system abnormalities. • Can have important implications for legal system and how responsible someone is for crimes. • It has been argued if the crime resulted from a medical condition such as a brain tumour they should not be punished. • Threatens the idea we act aggressively according to free will and are fully responsible for our own actions.
What is testosterone?	• The sex hormone that control the development of male sex characteristics (androgen). • Has role of regulating social behaviour via influencing certain areas of the brain.
Complete the following: Levels are around _ times higher in males than in females. Males are said to be ____ likely to engage in aggressive behaviour than females.	Levels are around 8 times higher in males than in females. Males are said to be more likely to engage in aggressive behaviour than females.
How testosterone affects aggression is still unknown, however, what has been found through studies of mice?	• Enzyme called aromatase. • Lacking in the brain. • Lack of aromatase = testosterone less likely to be activated. • Meaning potentially lower aggression.
Complete the following: Aromatase can also cause _____ activity in the orbito-frontal cortex, meaning in an _________ situation there is ____ likely to be an aggressive ________.	Aromatase can also cause lower activity in the orbito-frontal cortex, meaning in an emotional situation there is more likely to be an aggressive response.

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	Created by Emma Chell about 8 years ago