Put on a mask or a uniform, and your sense of personal responsibility can evaporate
Philip Zimbardo's deindividuation theory holds that anonymity, group immersion and reduced self-awareness loosen the grip of personal norms, making people act in ways they'd never consider alone and face-to-face. Crowds, costumes and online anonymity can all lower the same psychological guardrails. The idea traces back to Gustave Le Bon's 1895 writing on crowd psychology, decades before Zimbardo gave it an experimental footing.