Ego as a Source of Denialism

In my last post, I discussed a hypothetical model for the emergence of religion. After having talked to one of my friends about this idea, he came to the conclusion that ego is the source of denial-ism.  According to the model, a genetic propensity to be egotistical evolved or increased in frequency dramatically after the advent of religion. Once the individual has invested in believing the memes, ego causes him or her not to be able to question them. Doing so would be to admit having been wrong, which is a threat to the ego.