When the id component of the human psyche signals the desire to act on an impulse, the ego and super ego will often counteract it if they feel that that behavior would be counterproductive or immoral. A person may want to curse after falling over in a busy street, but the ego, perceiving this as contradicting social etiquette, will often lead to them holding back on the expletives. On some occasions, however, we may not be able to balance the impulses of the id and will defend the ego by simply acting out the irrational desires.

For example a person might “act out” by theatrically storming out of a stressful meeting when they would otherwise stay calm and hide their unease.