Psychology of Crowds by Gustave Le Bon
A foundational work in social psychology exploring crowd behavior. Le Bon examines how individuals lose personal identity in groups, becoming susceptible to irrationality and emotional influence, shedding light on mass movements, propaganda, and the dynamics of collective behavior.

Gustave Le Bon (1841–1931) was a French social psychologist and author of The Crowd: A Study of the Popular Mind. He explored mass psychology, collective behavior, and the influence of leaders on crowds, contributing to early theories of group dynamics and political influence.