"How swearing achieves its physical effects is unclear, but the researchers speculate that brain circuitry linked to emotion is involved. Earlier studies have shown that unlike normal language, which relies on the outer few millimeters in the left hemisphere of the brain, swearing relies on the right half"
Sursa: https://www.scientificamerican.com/article/why-do-we-swear/
Da dar daca injuri des scade din efect sa stii, asa cateodata e ok, se elibereaza dopamina in creier si poate ca de asta, efect placebo