Yelling, venting, or punching a pillow when you’re mad only makes you angrier in the long run. This trains your brain to associate anger with aggression and creates a counterproductive cycle: the aggression makes you feel better, the rush you get from being angry then becomes addictive, and you end up forming a habit. Basically, allowing yourself to lash out in anger is like getting drunk to control your urge to drink. Source Source 2