Group Psychology and the Analysis of the Ego (German: Massenpsychologie und Ich-Analyse) is a 1921 book by Sigmund Freud, the founder of psychoanalysis.

"The masses of the former type, so to speak, ride on the latter, like the short but high waves on the long swell of the sea.

Freud refers back to his theory of instincts and believes that masses are held together by libidinal bonds.

[5][6] Freud initially called the (largely unconscious) identification with the other individuals of the mass, all of whom are drawn in the same way to the leader, a binding element.

Thus, Freud came to the conclusion: "A primary mass is a number of individuals who have put one and the same object in place of their ego ideal and consequently identify with each other.