The biological perspective tries to explain aggression as an evolutionary function, which is necessary for survival. Most of these theories are based on non-human animal experiments, extending the findings to humans. Lorenz, an ethologist, who was very influenced by Darwin’s theories, studied animal behaviour in natural settings. With these studies he came to believe that aggression was an inherited mechanism, which was also found in humans, creating a deterministic and reductionistic theory.
Lorenz stated that aggression was controlled by environmental cues called sign stimuli, which either would stop the animal from being aggressive or on the contrary cause it to be aggressive. As aggression is innate and therefore unavoidable, Lorenz thought that if humans did vacuum activities, like exercise, was necessary to avoid having an aggressive behaviour against another. This process to reduce aggression levels was called catharsis.
Lorenz’s theory was very useful to understand animal behaviour with the sign stimuli, which was considered a great contribution; yet his theory lack s on human evidence as his findings are supported basically on non-human animal studies. Also the fact that it has not been found the human sign stimuli to cause aggression may suggest that aggression control mechanisms might be different to other species. There has been mapping of the brain to find where the aggressive behaviour is controlled, as localization of function; it has been found that the limbic area, in the evolutionary older regions, controls aggression.
Still this theory depends also on the analogy to animals’ studies, again lacking human evidence for it. Berkowitz showed evidence, which suggested humans had an aggressive response to pain or unpleasant feeling. This was an experiment done to humans where electrodes were placed on the brain causing electroshocks, which caused pain and made the person act aggressively, eventhough the brain does not have pain receptors.
With this he stated that aggressive responses were not only reflexes but cognitively mediated as well putting aside a deterministic theory. This theory, as it was tested on humans, has more evidence, which supports itself. This shows that eventhough the theories have reliable evidence, they still lack of human evidence, which means they can only give us an idea of what may cause an aggressive behaviour yet it cannot give us a full picture of what are the causes in humans.