Why Are Individuals Aggressive? Aggression is difficult to define, it is a complex phenomenon, and depending upon the context the term can be made to carry either positive or negative connotations, it can be attacking behaviour that may be either self-protective and self-assertive or to the infliction of injury toward oneself or toward others, to the total destruction of others. Is aggression biological determined or the product of learning and environmental influences.? This essay, will consider instinctive theory, the frustration - aggression hypothesis, and social learning theory. It should then be possible to draw a conclusion to see if any or all of the theori