Slides in this set
The role of the brain and
There are two parts in the brain which seem to be involved in aggression; the
limbic system and the amygdala. The limbic system is a set of brain structures in
the middle of the brain and is called the `emotional area' of the brain because it is
responsible for emotions needed for survival, like fear and aggression. The
amygdala is a structure in the brain that recognises emotion and creates
emotional responses, including aggression.
In 1961, King described a case study of a woman whose amygdala was
electrically stimulated during an operation. She became threatening and
verbally aggressive until the current was switched off.
In 1966 Charles Whitman killed 13 people from an observation tower, after
killing his wife and mother. He left a note behind asking doctors to examine his
brain because he thought something was wrong, and he was found to have a
tumour pressing against his amygdala.
Narabyashi et al (1972) studies patients whose amygdala was destroyed in
surgery. They were overall less angry/aggressive afterwards.
Wong et al (1997) found that criminals with more violent tendencies had
reduced size amygdalas.
Taming effect found in rhesus monkeys by removing the amygdala.…read more
Weaknesses regarding the link
between the brain and aggression
Studying the human brain is difficult and can be
very risky, so there is no way of being sure areas
of the brain are linked to aggression.
Animals and humans are different in many ways,
so animal research suggesting a link between the
brain and aggression may not be applicable to
Case studies are unreliable, as the reason for that
person's aggression may be unique to that
Aggression could equally be equally explained by
Social Learning Theory.…read more
The role of hormones and
In almost every culture, males are for more aggressive than females. This is
suggested to be because they have more testosterone. Testosterone is a male
sex hormone. A hormone is a chemical that is produced by the body, that sends
messages to organs of the body via the bloodstream.
Testosterone is secreted by the adrenal glands and testes and is needed to
produce sperm, develop the male reproductive organs and produce male
features, such as facial hair and a deep voice.
Psychologists have researched the role of testosterone in aggression by studying
animals. Injecting animals with testosterone or removing the testes lead to
increased or decreased levels of aggression.
Castrating a male animal lowers its testosterone levels. This makes the animal
less aggressive. But if the same animal is injected with testosterone, its
aggression is restored to a level similar to that before the castration.
Psychologists can take blood from humans to see what level of testosterone they
have compared to how aggressive they feel or act. Some correlation studies
(studies that see if there is a link between variables) have found a relationship
between high testosterone levels and questionnaire results showing greater
reported aggression. However, it s not certain whether testosterone causes
increased aggression, or aggression causes increased testosterone.…read more
Weaknesses regarding the link
between the brain and hormones
Not all humans with high testosterone levels are
aggressive. Some have greater sporting ability or
are driven in their careers. Testosterone creates a
drive, but this need not be a violent one.
Correlation and animal studies have weaknesses.
Animal studies may not apply to humans, and
correlation studies just look for evidence and are
not direct evidence.
If testosterone is the cause of aggressive
behaviour, why are some women more violent
than some men, and why aren't all me violent.
This explanation of aggression completely ignores
the huge impact of upbringing and social
circumstances on our behaviour.…read more
Social learning theory
Children learn through watching other people. This is called observational
learning. Modelling is the act of copying an observed behaviour. Observational
learning can take place without modelling; we don't copy everything we see, but
we still learn it. It involves four steps:
Attention paying attention to the person being observed.
Retention (Memory) being able to remember what we have seen until it is
Reproduction being able to act out what we see (this is modelling).
Motivation the incentive to copy what has been seen.
The person we observe and learn from is called a role model. This can be anyone
We are more likely to model a person who is popular, attractive, a similar age and
the same gender as us. Identification is when we adopt the behaviours, attitudes
and beliefs of a role model.
We are more likely to imitate someone if they think that there will be a reward in it
for us. Vicarious reinforcement is when we learn through the positive
consequences of other people's actions, and vicarious punishment is when we
learn through the negative consequences.…read more