Our political tradition sets great store by the generalized symbol of evil. This is the wrongdoer whose wrongdoing will be taken by the public to be the secret propensity of a whole community or class. We search avidly for such people, not so much because we wish to see them exposed and punished as individuals, but because we cherish the resulting political discomfort of their friends. To uncover an evil man among the friends of one's foes had long been a recognized method of advancing one's political fortunes. However, in recent times the technique has been greatly improved and refined by the added firmness with which the evil of the evildoer is now attributed to friends, acquaintances, and all who share his way of life.

--John Kenneth Galbraith (concerning vilification of Wall Street following the '29 crash)

It's not a human societies thing, it's a human thing.