"Instincts of the Herd in Peace and War" by Wilfred Trotter is a book published in 1916. This pioneering work explores how humans, like animals living in herds, possess a biological drive toward group behavior. Drawing on observations of sheep, dogs, and bees, Trotter introduces the concept of "herd instinct" to explain social motivation, conformity, and suggestibility. The collection examines how external social norms become internalized, shaping feelings of duty and obligation, with particular attention to these forces during wartime and their manifestation in nationalism and propaganda. (This is an automatically generated summary.)