TORONTO - In an extensive study of Palestinian suicide bombings, three University of Toronto researchers have concluded that the bombers were not psychologically unstable and were often motivated by personal vengeance, not religious zeal.

The study was carried out by political sociologist Robert Brym, with the assistance of two Ph.d students, Palestinian Bader Araj and Israeli Yael Maoz-Shai.

Writing in the academic journal Social Forces, Brym noted, "The organizers of suicide attacks don't want to jeopardize their missions by recruiting unreliable people. It may be that some psychologically unstable people want to become suicide bombers, but insurgent organizations strongly prefer their cannons fixed."

He also found that the suicide bombers did not experience extraordinary high levels of economic deprivation.

Furthermore, in his study published in Contexts, Brym concluded that a majority of bombers, like Palestinian female lawyer, Hanadi Tayseer Jaradat, 29, who killed 21 civilians in a 2003 bombing at Maxim restaurant in Haifa, were "motivated by the desire for revenge and retaliation."

Jaradat acted to avenge the killings of her brother, an Islamic Jihad militant, and cousin by Israeli security forces.

Brym concluded, "In its origins and at its core, the Israeli-Palestinian conflict is not religiously inspired, and suicide bombing, despite its frequent religious trappings, is fundamentally the expression of a territorial dispute." Brym and Araj identified the organizational affiliation of 133 out of 138 suicide bombers between September 2000 and July 2005. Sixty-four per cent were affiliated with Islamic fundamentalists groups such as Hamas and Islamic Jihad, while the rest were aligned with secular groups such as Fatah.

In analyzing data pertaining to Israeli counterterrorist operations, Brym said "we do know that of the nearly 600 suicide missions launched in Israel and its occupied territories between 2000 and 2005, fewer than 25 percent succeeded in reaching their target. Israeli counterterrorist efforts thwarted three-quarters of them using violent means."

However, his study found that harsh repression can intensify bombings and prompt bombers to devise more lethal methods to achieve their aims.

"In general, severe repression can work for a while, but a sufficiently determined mass opposition will always be able to design new tactics to surmount new obstacles. One kind of 'success,' usually breeds another kind of 'failure' if the motivation of insurgents is high." In an interview, Brym said: "I'm no fan of Hamas, but I believe that Israel and Hamas at some point have to sit and negotiate."

In a paper to be published in Studies in Conflict on Terrorism this year, Araj concludes that harsh state repression "should not be perceived only as a reaction to suicide bombing" but "often precedes and is a major cause of suicide bombing."