When I was a child, the idea of a pro-social lie came to me only with difficulty.
It took me a long time to accept that Santa wasn't real, because even at an age when his absurdity should have been obvious, I could not accept that my parents would perpetrate such an egregious lie. My embarrassingly late clinging to the Santa delusion directly led into an embarrassingly young crisis of faith.
I couldn't download the PDF, so I don't know if that has anything to do with this paper.
It makes sense. If Santa’s not real and Zeus is not real, then why not the Christian deity too!