I think a bunch of people here are concentrating on the wrong question. Whether a baby is born atheist or not is irrelevant. What we actually want to know is whether human beings have an innate tendency to see supernatural agency. And I think the fact that there has never been a human civilisation which has not had some sort of supernatural belief system strongly suggests that they do.
Yes. A very strong tendency to posit a transcendence of the mere empirical and give that personal content.
Even many Atheists functionally do that by identifying with their own consciousness as a persisting entity, even if mortal. I've often seen people on this board declare matter the substance or substratum of their self. (Materialism being a metaphysical or ontological assertion of what that which is behind the empirical is made of.) Or by insisting upon a metaphysical, above-animal Free Will. Self as a spirit, or something in the mode of spirit is the root of the concept of gods, even if you're an atheist but unconsciously regard your self as one.
So as I've said, self is projected upon natural objects, processes, and elements. Self is projected as a spirit that transcends the empirical form.
A Great Spirit is projected for Nature as a cosmic body. Or the objectified Transcendence becomes a content outside the physical world: a tinkerer, designer, or creator in the image of Human activity and interaction.
This is especially strong, because storytelling is older for our species than rational explanations. The temptation to posit a Protagonist is very strong and takes a good deal of awareness to counter.
Personally, I've felt the presence of God many times. I can at will put myself in such a state of consciousness. I can also at will feel the spirit of a tree.
It's in knowing what I'm doing that these experiences don't still make a theist of me. I have a felt sense of those personal feelings having such a stamp of reality that I know better than to argue with a person who cites them as their reason to believe. Until they invest in some self-scrutiny, they will believe, rationalize that belief, and force fit empirical fact to it. The story is too enchanting.
BTW fear of thunderstorms and waving a magic feather at the clouds to produce rain was never the cause of my theism. Though I confess it was comforting to turn my worries over to a heavenly parent. Since those days I've learned accept reality.