I believe that many of those jumping are in a state of shock and not consciously making a deliberate decision. They have an instinctive reaction to flee the horror of a death by fire, and even perhaps a subconsious desire to preserve, as best they can, their physical bodies, even beyond death. At least their families will have something to claim and to give a decent burial. But I think very few of them are actually aware of what's triggering their behaviour, and I'd hardly call it making a choice.

The suicide on the part of the terrorists is truly an act of punching their ticket to Paradise. It may on the surface be astonishing and impossible to understand how individuals could willingly kill themselves by crashing airplanes into buildings. However, it's easier to understand it when you consider the longterm, well-planned process of recruitment, indoctrination, brain-washing, etc. by the leaders and organizers of the Islamic terrorist networks. Young male teenagers are selected from mainly impoverished families in Muslim communities in various nations, the terrorists give a generous cash payment to the family, and honor them in many ways for their noble contribution to the war between Islam and the infidels, the young men are isolated for literally years in terrorist training camps for religious indoctrination and military and espionage training, and by the time they're sent on their missions, they're little more than brain-washed robots programmed for a deadly mission.