I have often been asked this question by parents... and even more so by my wife as we try to clean the snot off our little kids' noses as they shriek as if we're torturing them. Given it seems ALL young kids have this nose-wiping aversion across cultures and racial ethnicities, it would seem that this reflex reaction is hard-wired into human babies. But why would evolution favor this reaction? I tried to find an answer to this question to see if any bright researchers actually stu…