David Brooks(Josh Haner/The New York Times)

After the terrorist attack in San Bernardino, some people’s minds flew to the materialistic element of the atrocity — the guns that were used in the killing. But the crucial issue, it seems to me, is what you might call the technology of persuasion — how is it that the Islamic State is able to radicalize a couple living in Redlands, California? What psychological tools does it possess that enable it to wield this far-flung influence?

The best source of wisdom on this general subject is still “The True Believer,” by Eric Hoffer, which he wrote back in 1951. Hoffer distinguished between practical organizations and mass movements. The former, like a company or a school, offer opportunities for self-advancement. The central preoccupation of a mass movement, on the other hand, is self-sacrifice. The purpose of an organization like the Islamic State is to get people to negate themselves for a larger cause.

Mass movements, he argues, only arise in certain conditions, when a once sturdy social structure is in a state of decay or disintegration. This is a pretty good description of parts of the Arab world. To a lesser degree it is a good description of isolated pockets of our own segmenting, individualized society, where some people find themselves totally cut off.

The people who serve mass movements are not revolting against oppression. They are driven primarily by frustration. Their personal ambitions are unfulfilled. They have lost faith in their own abilities to realize their dreams. They sometimes live with an unrelieved boredom. Freedom aggravates their sense of frustration because they have no one to blame but themselves for their perceived mediocrity. The successful mass movement tells such people that the cause of their frustration is outside themselves and that the only way to alter their personal situation is to transform the world in some radical way.

To nurture this self-sacrificing attitude, the successful mass movement first denigrates the present. Its doctrine celebrates a glorious past and describes a utopian future, but the present is just an uninspiring pit. The golden future begins to seem more vivid and real than the present, and in this way the true believer begins to dissociate herself from the everyday facts of her life: Her home, her town, even her new child. Self-sacrifice is an irrational act, so mass movements get their followers to believe that ultimate truth exists in another realm and cannot be derived from lived experience and direct observation.

Next mass movements denigrate the individual self. Everything that is unique about an individual is either criticized, forbidden or diminished. The individual’s identity is defined by the collective group identity, and fortified by a cultivated hatred for other groups.

There’s a lot of self-renunciation going on here. Ironically the true believer’s feeling that he is selfless can lead to arrogance and merciless cruelty. It can also be addictive. If the true believer permitted himself to lose faith in his creed then all that self-imposed suffering would have been for nothing.

These movements generate a lot of hatred. But ultimately, Hoffer argues, they are driven by a wild hope. They believe an imminent perfect future can be realized if they proceed recklessly to destroy the present. The glorious end times are just around the corner.

The big thing that has changed in the past 60 odd years is that you don’t actually have to join a mass movement any more. You can follow it online and participate remotely.

The correct response is still the same, however. First, try to heal the social disintegration that is the seedbed of these movements. Second, offer positive inspiring causes to replace the suicidal ones. Third, mass movements are conquered when their charisma is destroyed, when they are defeated militarily and humiliated. Then they can no longer offer hope, inspiration or a plausible way out for the disaffected.

— David Brooks is a columnist for The New York Times.