In 1896, the social psychologist Gustave Le Bon warned his contemporaries of the dangers of crowds, writing that, "It is necessary to arrive at a solution to the problems offered by [crowds'] psychology, or to resign ourselves to being devoured by them." As spontaneous protest overtakes organized political movements across the Arab world, the leaders of Tunisia, Egypt and Libya's nascent democracies should heed Le Bon's warning.

Since crowds took to the streets of Tunis, Cairo, Benghazi and other Arab cities, toppling decades-old regimes, spectators and analysts have wondered where the Arab world is headed. But they have focused almost exclusively on the events' political dimension: Who are the leaders, and what are their demands?

In fact, the persistence, intensity and frequency of protests — exemplified in September, when local militia in Benghazi killed U.S. Ambassador to Libya J. Christopher Stevens — demonstrate the role that the culture and psychology of crowds are playing in determining the Arab world's trajectory. After decades of authoritarian rule, citizens, frustrated with discredited institutions and paralyzed political parties, have begun to employ social media to organize civil resistance.