It's worth asking whether the "predisposition" is entirely a function of Islam.

You could argue that what we call Islamic radicalism is largely a reaction to the same toxic batch of colonial/neocolonial/postcolonial unpleasantness that drove so much of the world toward leftist radicalism not so long ago. According to that argument the same basic motivations coalesced around a different ideological base in different environments, and we should be paying less attention to the ideological base and more to the driving impulse.

I'm not saying that argument is 100% right or universally applicable, but there is merit in it and it shouldn't be ignored.