biological Flashcards
brain aggression
Prefrontal cortex - rational thinking & impulse control.
Raine et al 1997 found murderers had higher levels of activation in amygdala, but lower activation in prefrontal cortex.
Amygdala - threat perception, emotion regulation and motivation.
Coccaro et al 2007 found that people who have extreme reactive aggression show higher levels of amygdala activity when viewing images of angry faces.
Serotonin
A common neuro transmitter widespread with inhibitory effects
Virkkunen et al found that levels of serotonin are significantly lower in the spinal fluid of violent people.
Dopamine
Imcreased levels of dopamine increases impulsivity and aggression but with low serotonin its even more aggressive.
Seo et al said this
raine et al s w
Strength
High control with standardised procedures - PET brain scan and regions measured kept same.
Extraneous variables could have affected brain activations during tasks - cause effect relationship between the brain and the violent behaviour
weakness
Small subset of violent criminals
- 41 all pleaded insane.
Not a conclusive explanation of criminal and violent behaviour as may not apply to other criminals (abusers, drug dealers), or emotional aggression.
drugs
Recreational drugs: drugs taken for enjoyment rather than medical reasons
Strength
- knowing the drug effect on the CNS, more treatments are available to treat addiction
Weakness
May be ethnocentric to western cultures
Wetherall copied tajfel study with polynesian new zealand kids and they distributed points much fairer.
TMT other factors than groups may have affected the prejudice like culture
drugs procedure
Procedure
Cocaine
Stimulant drug-activates CNS
Acts on reward system
Dopamine is reward neurotransmitters that causes a pleasant feeling
Cocaine blocks the receptors that lead to the neurons meaning that flooded with dopamine
Heroin tricks body to release endorphine relieving stress and pain. Slow CNS
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Strength
- knowing the drug effect on the CNS, more treatments are available to treat addiction
- can lead to the development of an antagonist for the drug- helo reduce withdrawal symptoms
Weakness
drugs and cns transmission- animal studies
brain scans procedure
Procedure
Structural- deals with structure of nervous system
Functional- what the brain is doing or what is active during tasks
CAT- x-rays that pass through the brain- measures what areas of brain is damaged or tumours.not how it functions
PET- tracer injection, gamma rays can be found in areas of high activity and images will show. Glucose usage high=more active
FMRI-a very powerful electromagnet
Areas of the brain that use more oxygen are more active - functional
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Strength
Reliable and objective way to measure brain activity.
Comparing measurements against observed behaviours - establish connections between brain areas and behaviours.
Weakness
Shows certain areas are more active in aggressive individuals - but unsure if activation causes aggression.
Some researchers argue aggressive behaviours cause brain structures to change.
cat scan
Structural Imaging
Uses X-rays that pass the brain in multiple angles to get more information.
Computer creates image of brain.
X-Ray radiation = damage unborn babies.
Measures the areas that are damaged or tumour positioning.
Strength
Very quick to conduct - shows accurate details of the brain.
Quality of these images can show tumours or structural damage - leads to better understanding of the area.
Weakness
Cannot show how brain is functioning, only structural information.
Limited use in linking brain areas to specific behaviours.
raine et al procedure
Aim - whether the brain was related to violent behaviour.
41 NGRI and 41 control
Procedure
Participants given tracer injection - chemical will make brain areas light up in scan.
Did a series of tasks on computer for 32 minutes.
The tasks activated areas of interest
PET SCANS
brendgen procedure
aim: to investigate aggression in MZ and DZ twins to discover the extent to which social and physical aggression can be explained by genetic and environmental influences
- 234 pairs of twins were sleected from QNTS
- the study collecetd data on them till they were 6 yrs
- The sample was 44 pairs of male MZ twins, 50 pairs of female MZ twins, 41 male DZ twins, 32 pairs of DZ twins.
- Levels of aggression were also recorded from the children’s peers.
- Each classmate was checked to see if they knew everyone in their class, then they were shown 3 photos of their classmates
- Each classmate was checked to see if they knew everyone in their class, then they were shown 3 photos of their classmates
- They were to nominate the 3 children on the page to the description that best fit them.
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STRENGTH
- ratings from many sources were utilised
teacher and peers. if there was a large difference between the teacher and peer highlights bias against the child but they were similiar
culture and gender may affect
weakness
Generalising interventions for aggression from this study may not be possible, as the age group being studied is highly specific - 5months -6 years
evolutionary theory procedure
Aggression might be a behaviour that links to sexual selection.
Being more aggressive might lead you to be able to scare off potential competitors or fight for resources for survival.
The aggression gene/characteristics might have allowed the human to reproduce in the first place, this might be why aggression still exists today
Size and strength of the human male might be seen as attractive. Competition between males might explain the higher aggression in men.
Steiner (2016) finds that protecting children is one of the rare instances where men and women are equally aggressive.
Protecting the children evolutionarily makes sense as they are how you pass off your genes
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strength
Hill and Hurtado (1996) found that heightened aggression was linked to higher social status in tribal communities in South America. This is associated with more access to food, and benefits chances of reproducing with a mate.
weakness
Wolfgang and Ferracuti (1967) found that the Kung San people (From Kalahari region in Africa) have very low levels of aggression, as that behaviour is discouraged from childhood.
Whereas the Yanomami people of Venezuela and Brazil are much more aggressive, as aggressiveness was used to gain status in their society.
freud procedure
Eros - life instinct.
Thanatos - death instinct.
ID - gain pleasure of its urges.
Superego - Morals, what is right and wrong.
Ego - how to exhibit urges in socially acceptable way.
Sublimation - non destructive way (venting, playing sport).
Displacement - redirect to substitute (younger sibling).
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Strength
Graham et al 2008 - good to process aggression. Sample of 50; ranting and processing emotions had improvement in control over pain and mood.
Suggests that expressing anger = health benefits. Links to Freud’s concept of catharsis.
Weakness
Bushman 2002 - made 600 students angry by getting confederate to criticise an essay they wrote.
Students that vented by hitting a punching bag were the most aggressive with the confederate.
Opposes Freud’s theory of aggression being cathartic - heightens aggressive behaviour
