The (Un-)Wisdom of Crowds

"The characteristics of the reasoning of crowds are the association of dissimilar things possessing a merely apparent connection between each other, and the immediate generalisation of particular cases. It is arguments of this kind that are always presented to crowds by those who know how to manage them. They are the only arguments by which crowds are to be influenced. A chain of logical argumentation is totally incomprehensible to crowds, and for this reason it is permissible to say that they do not reason or that they reason falsely and are not to be influenced by reasoning. ... Crowds are to some extent in the position of the sleeper whose reason, suspended for the time being, allows the arousing in his mind of images of extreme intensity which would quickly be dissipated could they be submitted to the action of reflection. Crowds, being incapable both of reflection and of reasoning, are devoid of the notion of improbability; and it is to be noted that in a general way it is the most improbable things that are the most striking. ... Whatever strikes the imagination of crowds presents itself under the shape of a startling and very clear image, freed from all accessory explanation, or merely having as accompaniment a few marvellous or mysterious facts: examples in point are a great victory, a great miracle, a great crime, or a great hope. Things must be laid before the crowd as a whole, and their genesis must never be indicated. A hundred petty crimes or petty accidents will not strike the imagination of crowds in the least, whereas a single great crime or a single great accident will profoundly impress them, even though the results be infinitely less disastrous than those of the hundred small accidents put together." from The Crowd, by Gustave le Bon.