Aggression: The term aggression refers to any behavior intended to cause harm or inflict pain on others. In this context, it could explain why someone might respond aggressively when insulted.
Frustration: Frustration occurs when one's desires or goals are blocked or hindered. If being insulted leads to frustration, it may increase the likelihood of an aggressive response.
Self-esteem: Self-esteem is an individual's evaluation of their own worth and value. If insults threaten one's self-esteem, it may provoke an aggressive reaction as a means of defending their self-worth.