From what I can gather suicide bombers and the like are pretty normal people. Part of what makes normal people normal is that they're relatively easy to influence.

Well, suicide bombers are more likely to have engineering degrees than the general public. There's also some evidence that engineers are surprisingly likely to be creationists. I don't think engineers are evil mutants, but it does suggest that there are certain modes of thinking that are likely to have bad results. To repeat fairly standard speculation in this regard, engineers aren't taught critical thinking and are taught to not tolerate uncertainty. This is not a good combination.