In this book, Le Bon claims that there are several characteristics of crowd psychology: "impulsiveness, irritability, incapacity to reason, the absence of judgement of the critical spirit, the exaggeration of sentiments, and others..."
He argues that, "By the mere fact that he forms part of an organised crowd, a man descends several rungs in the ladder of civilisation. Isolated, he may be a cultivated individual; in a crowd, he is a barbarian — that is, a creature acting by instinct. He possesses the spontaneity, the violence, the ferocity, and also the enthusiasm and heroism of primitive beings, whom he further tends to resemble by the facility with which he allows himself to be impressed by words and images — which would be entirely without action on each of the isolated individuals composing the crowd — and to be induced to commit acts contrary to his most obvious interests and his best-known habits. An individual in a crowd is a grain of sand amid other grains of sand, which the wind stirs up at will."