@gollum,
A little girl was killed the other day. She was asked to carry a package. An innocent doing a favour isn't really recruitment though.
I suspect most have little education, little hope of a good job and a whole lot of peer pressure. Not exactly martyrs, just angry, impressionable, kids with hopeless futures.
I watched a news show once where they interviewed a couple of suicide/terror suspects. They had shot dozens of people, set off bombs and created general mayhem somewhere in India. They were told the bank would be filled with westerners. They had no idea what westerners looked like, they thought everyone in the bank was in disguise. They didn't even know why westerners were bad, but they were told we were, so we must be.
And of course then there are the lunatics, the fanatics, the psychotically insane.