Weakness - research attempts to generalise results from animals to humans
this is a limitation because human aggression varies with the use of weapons and levels of violence, and there are psychological stressors that affect humans more than animals such as financial pressures. This means the causes of human aggression may not be the same for humans and animals, and the ethological explanation jeopardises its scientific credibility by making generalisations of humans
however, there are studies that show that human aggression may because by activity in the limbic system as a response to threat or stimuli, which suggests that just like animals, humans do have IRMs which may lead to aggressive behaviours