Biological Explanation of Aggression

• Hormones cause aggression – males are more aggressive than females, males have the hormone testosterone.

– Evidence shows that violent criminals have higher levels of testosterone than non-violent criminals

• Chromosome abnormalities – there is a higher proportion than normal of males with an extra Y chromosome amongst violent offenders. This is where the 23rd chromosome (the sex chromosome) fails to divide properly giving XYY instead of XY

• Brain damage – the areas of the brain associated with aggression are the limbic system and the prefrontal cortex. The limbic system is the part of the brain responsible for instinctive behaviours such as eating, sex and aggression. The prefrontal cortex is involved in learning and acts as a check on our instinctive behaviours – when it is appropriate to show it and when it is not.

Psychodynamic Explanation of Aggression

• Freud argued that the mind is like an iceberg and that it is the unconscious mind that dominates our behaviour. Two forces are dominant, the libido (sexual instinct) and thanatos (aggressive instinct)

• Freud stated that the personality is made up of three parts, the Id, Ego and the Superego.

• You are born with your Id and it is dominated by sex and aggression

• You develop your superego between the ages of 3 and 5 when you adopt the morals and values of your same sex parent

• Your ego has to balance out the demands of the Id with the feelings of guilt from the superego. To do this it uses ego defence

mechanisms.

• There are a number of ego defence mechanisms that we use to protect ourselves from harm

– Displacement is where you redirect your anger towards other people

– Sublimation is where you push your aggression into socially acceptable activities

– Repression is where you bury harmful thoughts or shameful experiences into your unconscious mind

• Dollard said that people are not aggressive for no reason. Instead he came up with the frustration-aggression hypothesis. He stated that our anger is only released if something provokes us, for example if we lose something we may shout in annoyance.

Social Learning Explanation of Aggression

• We learn aggression by imitating models – we see what other people do and we copy it. This is sometimes called vicarious learning.

• We are more likely to copy models if they are the same sex, age or have a high status.

• We are more likely to copy a model if they are rewarded for their actions – this is known as vicarious reinforcement

• Rewards can also be internal – if we do something bad and it makes us feel good, we are more likely to repeat this behaviour

Studies of Aggression

Explanation Biological Psychodynamic SocialName Raine (1997) Barker (1941) Bandura et al (1963)Aim To investigate the

brains of murderersTo see the effect of frustration on aggressive behaviour

To find out if children will imitate aggressive behaviour towards a ‘bobo doll’

Method 41 murderers were given a PET scan, these were compared to the brains of non-murderers

Children were kept waiting before been allowed to play in a room full of attractive toys, others were allowed to play straight away

96 children were split into 4 groups. 3 groups saw an adult kicking, punching and throwing the bobo doll. The children were then observed playing.

Results There was less activity in the prefrontal cortex in the murderers group

Those who had been kept waiting were more aggressive and destructive in their play

The children who had seen the aggressive role model showed more aggression than those who had not seen this.

Conclusion When they prefrontal cortex is not working properly it can lead to people committing violent crimes

Being frustrated leads to aggressive behaviour

Children will copy how they see others behave

Evaluation PET scans are an objective way of measuring the brain and differences can be measured statisticallyIt could be that the act of violence leads to changes in the prefrontal cortex and not the other way round as the researchers suggest

It is unethical to cause frustration in young children as it is placing them under unnecessary stressIt could be that by chance the children who were made to wait were naturally more aggressive anyway

The study was a lab experiment so may not reflect real life behaviour – for instance in real life an adult may explain why the behaviour the child is observing is wrongA real life study carried out on the Island of St Helena showed that aggressive behaviour did not increase after TV was introduced to the island

Treatments for Aggression

Biological:

Drugs such as Ritalin (used for ADHD) can reduce aggressive behaviour. They work by increasing activity in the prefrontal cortex

Psychosurgery can be used by inserting a probe into the brain to kill the nerves. You can destroy parts of the limbic system to reduce aggressive behaviour

Evaluation:

Drugs have side effects which are often unpleasant Once you stop taking the drugs the symptoms will come back Psychosurgery is irreversible – once the brain is destroyed it cannot fully repair itself Psychosurgery can lead to a person being in a vegetative state

Psychodynamic:

Catharsis can be used to release aggression – catharsis is the release of emotion by watching other people experience emotion. According to Freud, watching violence should help a person to release their aggression

Defence mechanisms can make people less aggressive. For example, sublimation is where you channel a negative emotion such as aggression into something positive, like playing sport

Evaluation:

It is impossible to test whether or not defence mechanisms or catharsis exists because they happen on an unconscious level

Research contradicts the idea that watching violence makes you less aggressive as many studies show that there is a link between watching violence and aggressive behaviour

Social:

Watching a role model commit an aggressive act and receive punishment for it will reduce aggressive behaviour. Bandura showed that children were much less likely to copy an adult behaving aggressively if they had seen them be punished for their actions

Explaining to children that aggression they are observing is wrong can lead to a reduction in aggressive behaviour

Evaluation:

If the punishment is not as big as the reward gained from carrying out the aggressive act then the threat of punishment will not be a deterrent

An adult is not always present to explain the consequences of violence that a child has observed.

Key Terms – You need to be able to define the following:

Aggression

Hormones

Testosterone

Chromosomes

Vicarious Learning

Imitation

Punishment

Vicarious reinforcement

PET Scan

Repress

ADHD

Ritalin

Psychosurgery

Catharsis