In several different places I have come across this
interesting article by Gal and Liu. Exerting self control is usually assoicated with positive emotions and wellbeing, but some research has also shown that exerting self control can lead to increased aggression. The authors:
...find that exerting self control is associated with angry behavior more broadly. In particular, using a “matched-choice paradigm,” we find that after exerting self control people exhibit increased preference for anger-themed content, greater interest in faces exhibiting anger, greater endorsement of anger-framed appeals, and greater irritation to others‟ attempts to control one‟s behavior.
The authors note that because the anger-related behaviors examined in their experiments are not inappropriate, they are unlikely to reflect diminished capacities of self-regulation. Three of the several possible reasons why exerting self-control might elicit (implicit) anger they list are:
Goal Frustration - primitive and evolutionary roots drive angry facial expressions and the autonomic response of facial flushing in a newborn baby when a sucking treat is removed.
Diminished sense of Autonomy - anger from the sense that one‟s sense of freedom is restricted and that one is "forced" to choose the virtuous path rather than indulgence.
Ego depletion - the state of being depleted (not having the short term goal deferred for the long term goal) makes people angry.