Hormones- Males are more aggressive than females. Hormone difference may be responsible as men have more testosterone than women and this has been supported by criminals have a higher level of testosterone.
A- To see what effect hormones have on aggressive behaviour.
M- Young injected pregnant Rhesus monkeys with testosterone and observed offspring.
R- Females grew up like male monkeys, challenging for dominance and becoming aggressive.
C- Testosterone plays a vital part in aggression.
Ev- not ethical and monkeys do not have a say and cannot pull out, cannot generalise to humans. It does provide evidence for a biological explanation.
Chromosomes- a Higher proportion of mean with extra Y chromosome among murderes. The 23rd chromosome fails to divide so there is an XYY arrangement.
Brain disease- Prefrontal cortex involved in learning and brain disease affecting the limbic system or prefrontal cortex can lead to aggression.
A- To investigate the brains of murderers
M- 41 murderers were given PET scans and they were compared with a group of non-murderers.
R- Activity in the prefrontal cortex was lower in the murderers.
C- When the prefrontal cortex and brain are not working properly it can lead to violent crime.
Ev- Cannot generalise to public. Supports theory.
Freud believed our aggressive instincts were caused by Thanatos which is an internal drive that causes our aggressive drive. It builds up inside and creates pressure until we burst. WE protect ourselves by using ego defence mechanisms such as displacement (being aggressive towards people) and sublimation (putting aggression into suitable activities).
Dollard believed it was frustration the pushed us over the edge and it can be caused by veryday things.
A- To see the effect of frustration on aggressive behaviour.
M- children were kept waiting before being allowed to play with toys. Their behaviour was observed.
R- The children who waited were more aggressive and destructive than those who didn't.
C- Being frustrated does lead to an increase in…