Altered Mental Activity

"We started from the fundamental fact that an individual in a group is subjected through its influence to what is often a profound alteration in his mental activity. His emotions become extraordinarily intensified, while his intellectual ability becomes markedly reduced, both processes being evidently in the direction of an approximation to the other individuals in the group; this result can only be reached by the removal of those inhibitions upon his instincts which are peculiar to each individual, and by his resigning those expressions of his inclinations which are especially his own."

― from "Group Psychology: The Analysis of The Ego,…" by Sigmund Freud