While some people respond to feelings of powerlessness and insignificance by turning to humanitarian aims -- becoming a peace activist, for example -- would-be terrorists draw on violent ideologies. Violence is a quick shortcut to feelings of significance, Kruglanski said.
"Violence enjoys this very clear advantage, that by striking, by shooting, by exploding a device, a very simple action immediately makes you out to be a significant, heroic kind of person," Kruglanski said.
View of victims In this worldview, the innocent victims of a bomb are subhuman, at worst, and incidental, at best. Timothy McVeigh, whose 1995 bombing of a government building in Oklahoma City killed 168, famously described the 19 children who died in the blast as "collateral damage."
"For a person who engages in this kind of activity, the immediate victims are meaningless. They're simply a means to an end," Horgan said. (Science of Terrorism: 10 Effects of 9/11 Attacks)
It's hard work maintaining that belief. Horgan, who has interviewed nearly 200 terrorists around the world, said some eventually come to feel remorse for the innocent lives they took. But especially in the moment, many "work very hard to convince themselves that what they've done is righteous."