Slides in this set
The biological approach to aggression assumes that
aggression is caused by the individuals biological make-
up, and environment has no effect on making a person
aggressive or not.
· Research has shown that there are relationships between
criminal behaviour, and abnormally high levels of certain
hormones, but the link between aggressive behaviour and
biological mechanisms isn't that simple.
An introduction…read more
Neurotransmitters are chemicals that pass impulses from
one part of the brain to another, to transmit messages
· The two neurotransmitters that are researched for the link
between them and aggression are serotonin (5HT) and
· Low levels of serotonin are thought to increase
aggression, and high levels of dopamine are thought to
increase depression as well.
Neural factors…read more
Serotonin is thought to reduce aggression. This is done by
inhibiting responses to emotional stimuli that might lead to an
· Low levels of serotonin are thought to be linked to impulsive
behaviour, aggression, and violent suicide.
· Mann et al (1990) gave 35 healthy participants dexfenfluramine,
which is known to deplete serotonin. They used a questionnaire to
measure hostility and aggression, and after taking the drug, found
that males increased in aggression and hostility scores, but females
· Raleigh et al (1991) studied aggression in vervet monkeys. They
were kept in two conditions- one group were fed on a diet high in
tryptophan, and the others were fed on a diet low in tryptophan.
Tryptophan increases serotonin in the brain. Those who had a low-
tryptophan diet exhibited higher aggression than the other group.
Serotonin (5HT)…read more
High amounts of dopamine are thought to increase aggression.
Lavine et al (1997) found that dopamine activity increases via the
use of amphetamines, which increases aggressive behaviour.
· Antipsychotic drugs, which reduce dopamine in the brain, have
been shown to reduce violent behaviour in delinquents. (Buitelaar,
· Couppis and Kennedy (2008) found that in mice, a reward
pathway becomes engaged when exposed to an aggressive stimulus,
which involves dopamine. They suggest that individuals seek
aggressive encounters because they experience a rewarding
sensation from it.
However, this is reductionist as the study was conducted on mice,
which have a far simpler anatomy and social nature than humans,
so this research has issues of applicability.
Hormones are proteins that carry chemical messages
around the body.
· The two hormones that are researched in connection with
aggression are testosterone and cortisol.
· High levels of testosterone, and low levels of cortisol, are
thought to increase aggression.
Hormonal mechanisms…read more