Anger is an overpowering impatience accumulated from the residues of at least one thwarted expectation. In any circumstance where an individual is attempting to achieve an outcome or retain a status quo and the result continues to be either entirely frustrated or entirely unpredictable, each unsuccessful trial contributes a quanta of resentful irritation. The incremental growth of dissatisfaction will eventually reach a level where patience for further trials is exhausted. This final state is usually one of temperature and pressure-elevated disgruntle.

The repetition of unsuccessful trials in themself do not necessarily result in anger. Failing to find mammals in traps on an island designated to be mammal free would result in some satisfaction. The perseverence involved to repeatedly trying and sell a product that nobody wants will eventually result in bankruptcy.

To some extent the number of thwarted aspirations necessary to induce a significant anger is inversely proportional to the effort or investment involved in each of the trial events. Thus, although one may be resentfully philosophical the first time a letter-box is blown-up for fun and only builds up to a fully pressurised anger after the severalth time, a single home or country invasion or terrorist act which involves the destruction of people and irreplaceable heirlooms is probably going to induce an instant and irreconcilable anger.

Although different individuals have quite variable anger fuses, depending upon the weather, the hormones, social constraints, maturity, philosophical outlook, et al, never-the-less lurking around the containers of evident disgruntles should be regarded as a very hazardous exercise.