Many proponents of theism insist that there are no atheists in foxholes (a claim which is almost certainly inaccurate). But, suppose that they are correct. How can this possibly be considered a sound argument for the existence of God? It's probably true that people tend to turn toward their childhood religious beliefs when in life-threatening situations, but this is no surprise. The human brain has not evolved to be in a rational state at all times. In fact, quite the opposite. When under extreme duress, humans tend to be far more irrational than when in a calm state. So, why do theists consider to push the idea of their being "no atheists in foxholes" as an argument for the existence of God. If the best argument that you can come up with to defend the existence of the deity you believe in is pointing out the tendency of humans to return to irrational childhood beliefs when under duress, then why should I take any aspect of your faith seriously? Would I return to the beliefs that I was indoctrinated into as a child if my life was in danger? I don't know, but I wouldn't rule it out as a possibility. However, whether or not I would do such a thing has no bearing on reality.
Pointing out irrational psychological tendencies of human beings to believe in God or to fear the boogie man is an incredibly poor argument for the supernatural. In fact, we have evolved to believe in the irrational. If an ancient homo sapien heard a rustling in the bushes, it would be to his advantage to believe that it is a serious threat (even if this belief is inherently irrational). The reason is because in the one time out of 10 that it is an actual threat, he would survive, while more "rational" homo sapiens would perish. In the same way, the tendency for humans to return to irrational childhood beliefs is also likely a result of evolution, and the fact that believing irrational things when under duress leads to greater survival, and hence a greater probability of passing the "irrational under duress" genes onto the next generations.
