Limbic system AO3

• A limitation is that studies done into the limbic system can only show correlation, not causation. Whilst it is certain from studies like Bard and Mountcastle that aggressive behaviour and the limbic system are related, it does not prove the link that aggressive behaviour is caused by the limbic system. For example, there are plenty of people who would naturally have a lower amygdala volume but still function as a normal human and are not overly aggressive.
• the neural explanation of aggression is deterministic. By determining the sole reason for aggression as the limbic system, it leaves little room for free will of the individual. This would mean that individuals are not considered ‘in control’ of their behaviour if their aggression is only caused by the limbic system. This would imply that people are not morally responsible for aggressive behaviour, which would harm the criminal justice system as criminals could use it as an excuse, saying their behaviour was not in their control and was only because of abnormalities in their limbic system.
• Bard and Mountcastle looked at rage in cats caused by a detachment of the higher and lower brain through lesioning, concluding that the hypothalamus initiates aggressive behaviour and the cerebral cortex reduces this behaviour. This shows that the hypothalamus has a large role in initiating aggressive behaviour, supporting that the hypothalamus involves the evaluation of a current threat compared to past experiences.
• However, this is limited by the fact that cats have a very different brain structure to humans so it could be that the hypothalamus would play more of a role in the cats than it would for a human, whose brain is significantly more developed. Therefore, this research lacks external validity and may not apply to the human population.