Anger or wrath is an intense emotional response. It is a normal emotion that involves a strong uncomfortable and emotional response to a perceived provocation. Often it indicates when one's basic boundaries are violated. Some have a learned tendency to react to anger through retaliation. Anger may be utilized effectively by setting boundaries or escaping from dangerous situations. Some people describe anger as a normal emotion that involves a strong uncomfortable and emotional response to a perceived provocation. Raymond Novaco of UC Irvine, who since 1975 has published a plethora of literature on the subject, stratified anger into three modalities: cognitive (appraisals), somatic-affective (tension and agitations), and behavioral (withdrawal and antagonism). William DeFoore, an anger-management writer, described anger as a pressure cooker: we can only apply pressure against our anger for a certain amount of time until it explodes.