Comparing notes with the Israelis, it was found that al Qaeda and the Palestinian terrorists agreed that, in general, the "best" candidates to recruit for suicide operations are poor, uneducated young men with low self-esteem. These poor lads can be easily indoctrinated. Since they are uneducated, but not stupid, they can be quickly taught the necessary skills to enhance their chances of carrying out their attacks successfully.
One reason for Western nations cutting off over a billion dollars in annual aid to the Palestinians, unless Hamas (the new terrorist group that got elected as the new Palestinian leaders) makes some convincing noises about not being terrorists, is because paying large sums of money to the families of suicide bombers, is a big inducement for poor young guys to sign up. Young Palestinian, and Iraqi Sunni men, know that their future is bleak without cash to get married and start some kind of business. Arabs tend to put family before self, so it's a reasonable choice for a son to do a suicide bomber thing, knowing that the family will get respect, and a large chunk of change, because of it. The likeliest volunteer for this kind of job is the son with the most meager prospects. Namely, the one that did poorly at school, and has a low opinion of himself. Being a suicide bomber is one way to finally get some respect. And once you volunteer, and then until the time you actually do the deed (which might be weeks or months in the future), you get to enjoy the respect.