Forgive me, (or my Ego?), the room to be for once a little bit controversial. I would posit that those who are religious are bound to their ego's far more tightly than the atheist. On what grounds do I make such a statement? Simply put I propose that religious belief is itself nothing more than Ego. Every possible personal paradigm is the expression of the Ego since (a) in total honesty none of us has sufficient information to make any claim and (b) they all link straight back to what we "would like" to be true. In a sense religion as it manifests in groups is the collective "nudge-nudge, wink-wink" of complicity in allowing ego free reign. Religion panders beautifully to this, and of course it exploits it too.
The atheist does not just deny god in this light, he/she denies ego too. Subsequently it is easier for the atheist to be rational and unbiased.