I found this interesting.
Why Religious Beliefs Are so Vehemently Defended
Atheists and scientists do not kill each other over their beliefs. The adherents of superstring theory have never killed opposing theorists, and Lamarckian Evolutionists never killed any Darwinian Evolutionists on account of their beliefs. Newton and Einstein may have disagreed, but they refrained from violently attacking each other's followers. Like them, Arius and Athanasius disagreed over theory in the 4th century, although in their case it wasn't physics, but about the nature of Christ. The Arians and the Nicene Christians, however, soon ended up damning each other to hell because of the other's "wrong" beliefs, and then resorted to murder, aggression and burning until the Arians had been wiped out. Well, that is one way to settle a theoretical dispute. But why is it the religious way? There is something about religious beliefs that leads to violent intolerance. I think it is this: the beliefs that you cherish, but which you think are maybe silly or untrue, are the beliefs that you will defend most irrationally and most aggressively. It's a defence mechanism. Rather than subject dodgy beliefs to the rigors of debate and questioning, it is easier to claim outrage and act aggressively when dodgy beliefs are challenged. This is why scientists, who want to learn which theories best describe the truth, actively engage in debate without ever, in history, killing each other over their differences with other strands of scientists.