A crowd thinks in images, and ...

A crowd thinks in images, and the image itself calls up a series of other images, having no logical connection with the first...A crowd scarcely distinguishes between the subjective and the objective. It accepts as real the images invoked in its mind, though they most often have only a very distant relation with the observed facts....Crowds being only capable of thinking in images are only to be impressed by images.
 Gustave Le Bon

Quotes from the same author

In crowds it is stupidity and not mother wit that is accumulated.
 Gustave Le Bon
The greater part of our daily actions are the result of hidden motives which escape our observation.
 Gustave Le Bon
One of the most constant characteristics of beliefs is their intolerance. The stronger the belief, the greater its intolerance. Men dominated by a certitude cannot tolerate those who do not accept it.
 Gustave Le Bon
A crowd is not merely impulsive and mobile. Like a savage, it is not prepared to admit that anything can come between its desire and the realisation of its desire.
 Gustave Le Bon