aggression Flashcards
What does the biological approach suggest about aggression?
Aggression is due to the structure and function of our body, genes, brain anatomy, hormonal or neuronal activity.
What is the limbic system and the amygdala? How are they associated with aggression?
A network of structures deep in the brain with components important in behavioural and emotional structures especially regarding survival behaviours.
The amygdala is suggestively the most important in aggression as it chooses how to assess and respond to the environmental threats and challenges. The reactivity of the amygdala is a predictor of aggressive behaviour.
Using PET scans, what did Raine et al discover in (1997) and in (2000)?
1997: Used PET scans to compare the brains of 41 murderers and 41 controls ( non-aggressive individuals) and found that there were abnormalities in the limbic systems of aggressive individuals in comparison to the control suggesting that the limbic system has an implication in murder.
2000: Found that the prefrontal cortex (responsible for inhibiting aggressive behaviours) was 14% less active in non-abused murderers and 15% smaller in anti social males.
What is a weakness of Raine et al’s study?
His data was correlational and not direct evidence that aggressive behaviour is due to brain anatomy but rather could be a factor that influences it or something that develops over time.
What did the case study of Charles Whitman show?
Charles Whitman was a Texan marine who murdered his family and shot several strangers and took his own life.
His autopsy suggested that he had a tumour pressing on his amygdala in the limbic system, demonstrating a relationship between his highly aggressive behaviour and the limbic system.
What did the case of Summer at al (2007) show?
A case study of a 14 year old girl who was elliptic and violent as she had a tumour present in her limbic system after an MRI, After drug therapy, she was less aggressive, suggesting that the high levels of aggression was due to the tumour in the limbic system.
How does alcohol affect the brain and how does it affect aggression?
Alcohol reduces self awareness and will deindiviudate an individual by switching off the pre-frontal cortex and leaving the limbic system without cognitive control.
Helps explain why 4/10 violent crimes are committed by drinkers and a survey of rapists found hat 50% of them drank before committing the assaults.
Demonstrates the importance of brain structures in aggression. Wider implications could involve understanding alcoholic aggression.
What are some weakness of the limbic system explanation of aggression?
X The role of the limbic system is not clear in aggression as it is made up of several components however a majority of the study is conducted on the amygdala rather than the limbic system as a whole.
X The research does support the link between brain abnormalities and aggressive behaviour but this is only the correlation, not causation. There are other factors that it does not consider, for example the environment,
X Generally reductionist and deterministic, does not consider complex human emotions
What are some strengths of the limbic system explanation of aggression?
+ Research into the limbic system has lead to understand aggression due to brain structures and been helpful in developing drug therapy targeted at that area, for example Summer at al (2007)
+ Several supporting research such as Raine et al who shows a direct link between aggression and brain structures
+ Demonstrates the dangers of alcohol
How do neurotransmitters link to aggression?
High levels of dopamine and low levels of serotonin have been suggested to link to aggression
What is the role of serotonin in the brain and its association with aggression?
Serotonin has a widespread inhibitory effect on the brain by slowing and suppressing neuronal activity and is associated with having a greater deal of control.
Generally having a low level of serotonin is associated with aggression as it leads to less self control and greater deal of impulsive behaviours
What did Ferrari et al use his rats to study? How does this support the neurotransmitter theory of aggression?
Ferrari et al forced rats to fight at the same time for 10 days in a row straight and on the 11th day they were tested for neurotransmitter levels and discovered that they had an increase of dopamine but a lower level or serotonin.
Demonstrates the effect of aggression and how it can alter brain chemistry,
What did Raleigh et al discover with Vervet mokeys? How does this link to aggression?
Raleigh et al fed vervet monkeys high diets of tryptophan which increases serotonin levels in the brain and discovered that they exhibited lower levels of aggression.
This research shows how serotonin is important in the control of aggression.
What is the role of dopamine and how does it link to aggression?
Dopamine mediates the pleasure in the brain and is released during pleasurable situations that stimulate one to repeat an activity to receive pleasure again.
What link did Buitarr find with antipsychotic drugs and aggression(2003)?
Buitarr found that antipsychotic drugs , which reduce dopamine activity in the brain , have been shown to reduce aggressive behaviour in violent deliquents.
Demonstrates how dopamine is significant in understanding violent behaviour as when it is removed, aggression is reduced.
Evaluate the role of neurotransmitters in aggression
+ Led to the development of useful treatment for uncontrollable aggression such as drug treatments ( anti psychotics )
+ Has several cases of supportive research and is scientifically testable giving it reliability and validity
X A lot of research into neurotransmitters are conducted on animals due to ethical issues, this can have questionable generalisability due to large physiological differences in animals and societal norms which are also important in aggression
X Biologically deterministic and reductionist
X Ethical issues of using animals
What is testosterone and how is it implied in aggression?
Testosterone is an androgen responsible for the development of masculine features found in small amounts in women and is associated with aggression.
What did Mairead Dolan et al (2001) find about testosterone in a sample of 60 male offenders?
Found a positive correlation between testosterone levels and aggressive behaviours in this sample of maximun security prisons. They mostly suffered from personality disorders and had history of impulsive behaviours.
This was a natural occurring support so it had no ethical issues and demonstrate a clear correlation between aggressive behaviours and testosterone levels.
What did Stephaine Van Goozen find regarding sex changes and aggression?
People undergoing sex change operations , when women were transitioning into men, they had testosterone injections and became more aggressive whereas men into women had testosterone suppressants which decreased aggressive behaviours.
How does testosterone affect the OFC and what does this imply?
High levels of testosterone will limit the activity of the OFC, meaning that an emotional situation will produce a heightened emotion response as there is less decision making involved.
This suggests that biological explanations do not work in isolation to each other and interact to produce a response.
What did Carre and Mehta (2001) propose about cortisol?
Carre and Mehta proposed that the hormone cortisol acts antagonistically to testosterone and will reduce its activity when present. Testosterone will only cause aggression if cortisol is in low levels.
What are some strengths regarding the hormonal explanation of aggression?
+ Lots of supporting research that imply the correlation between testosterone and aggression
+ Helps us understand aggressive behaviours and find treatment based on drug therapy that influence hormones
+ Helps us understand the interactions between the neuronal and hormonal system in aggression
What are some cons of the hormonal explanation for aggression?
X Does not explain why some females show excessive violent behaviours even when they lack high testosterone levels, for example the female serial killer Myra Hindly assisted in several murderers.
X Aggression can be subjective and hard to measure and often involves the use of questionnaires or response to situations which are inaccurate
X Data is correlational but not cause and effect , there are other influential factors
X Biologically reductionist and deterministic
What did Coccaro et al discover about DZ and MZ twins regarding aggression?
Studied adult males MZ and DZ twins and found 50% concordance rates in MZ twins for direct physical assault cases whereas it was only 19% for DZ.
This highlights that genes do have an implication in aggression however is not the only factor due to not being 100% concordance rate.