By SARAH KERHSHAW

WHAT MOVES PEOPLE to kill themselves and innocent bystanders?

Until recently, the psychology of terrorism had been largely theoretical. Finding actual subjects to study was daunting. But access to terrorists has increased and a nascent science is taking shape.

More former terrorists are speaking publicly about their experiences. Tens of thousands of terrorists are in “de-radicalization” programs , and they are being interviewed, counseled and subjected to psychological testing, offering the chance to collect real data on the subject.

Terrorist propaganda has flooded the Internet and the thinking of sympathizers is widely available. But the new research has its limits. The accounts of the extremists - generally militant Islamists - are difficult to verify. And researchers often differ over the path to radicalization. Some boil it down to religion, others to politics and power, others to an array of psychological and social influences.

But even if the motivations for terror can be wildly idiosyncratic, a range of patterns have been identified.


1. The Path to Violence

Despite the lack of a single terrorist profile, researchers have largely agreed on the risk factors for involvement. They include what Jerrold M. Post, a professor of psychiatry, political psychology and international affairs at George Washington University, calls “generational transmission” of extremist beliefs, which begins early in life; a strong sense of victimization and alienation; the belief that moral violations by the enemy justify violence in pursuit of a “higher moral condition”; the belief that the terrorists’ ethnic, religious or nationalist group is special and in danger of extinction, and that they lack the political power to effect change without violence.

Research has also shown that some terrorists have a criminal mentality and had previous lives as criminals.

Paradoxically, anxiety about death plays a significant role in the indoctrination of terrorists and suicide bombers - unconscious fear of mortality, of leaving no legacy, according to new research. Many researchers agree that while there is rarely a moment of epiphany, there is typically a trigger of some kind to accelerate radicalization - for example, the politically related killing of a friend or relative.


2. Life in the Group

Most researchers agree that justification for extremist action, whether through re ligious or secular doctrine, is either developed or greatly intensified by group dynamics. Dr. Post said the Internet has given rise to what he calls a “virtual community of hatred.”

One theory holds that when people are in groups they are more likely to make risky decisions because the risk is perceived as shared and therefore is less frightening. As the group becomes more radical, so does the individual, who is also likely to feel enormous social pressure to agree with the group consensus.


3. Moral Questions

John Horgan, director of International Center for the Study of Terrorism at Pennsylvania State University, refers to the “internal limits” of terrorists.

For a book published last year, Dr. Horgan collected the accounts of 29 former terrorists, many of them defectors from groups like the Irish Republican Army and Al Qaeda. He found that terrorists must inherently believe that violence against the enemy is not immoral, but that they also have internal limits, which they often do not learn until they are deeply embedded in a group.

Some terrorists who accepted killing off-duty soldiers abhorred the killing of animals. Some are comfortable with only a limited number of casualties.


4. The Suicide Bombers

Once a terrorist, it is often difficult to turn back. This is particularly true for prospective suicide bombers. Once assigned to their fatal missions, they become known as “walking martyrs.” Backing down would create too much shame or humiliation.

Arie W. Kruglanski, a professor of psychology at the University of Maryland, College Park, who has studied videotapes of suicide bombers’ final words and interviews with their mothers, argues that the overarching motivation of suicide bombers is the quest for personal significance, the desperate longing for a meaningful life that appears only to come with death.


5. Leaving Terrorism

The reasons terrorists leave the life provide great insight into how their minds work, and their beliefs may be more subject to change than previously thought, Dr. Horgan said.

In one case, a former Al Qaeda recruit told Dr. Horgan that when he arrived to fight in Afghanistan, he was dismayed to find that children and the elderly were being forced into battles.

The man’s “image of this all-seeing, all-powerful, all-noble movement was receiving its first hard knock,” Dr. Horgan said.



As the group becomes more
radical, so does the individual.

Their beliefs may be more subject
to change than previously thought.

They inherently believe that violence
against an enemy is not immoral.

In a video, Humam Khalil Abu-Mulal al-Balawi, right, called for revenge. His suicide attack at a military base in Afghanistan killed seven C.I.A. officers./ AGENCE FRANCE-PRESSE — GETTY IMAGES