Catharsis is defined as an emotional release. It’s the idea that punching your brother when he made you mad will make you feel better. Honestly, sometimes I feel like it works. Your brother is being an idiot, you punch him and you feel better. Here’s one example of catharsis.
Lilo and her sister separate and scream into pillows. We like to think that somehow, letting out all of this aggressive energy will make us more ready to deal with the actual situation. Unfortunately, most theorists agree that catharsis is a myth. Rather than decreasing your need to aggress, letting out a little bit of that energy actually increases your desire to aggress.