Thankfully children are more robust than we might imagine.
Religious families 'brainwashing' their children at a tender age with the aim to ensure they remain religious for life. Yet half of those children as they become adults will conclude that, do you know what, all that religious stuff - don't believe a word of it. Pretty poor hit rate for all those hours teaching bible stories, sat in pews, making sure their children go to a school that will continue that brainwashing in the class-room as well as at home.
Compare that with the non religious - simply being non religious with no overt brainwashing and guess what - pretty well 100% of their kids will agree with that non religious position as adults.
I think the mixed family is the most interesting - so have 2 religious parents, 50% likelihood of remaining religious as a adult. Merely the presence of a single non religious parent in the household (typically in those cases the religious parent and their church expect their view to prevail) and that hit rate drops to 25%.
Demonstrates just how unimpressive and unconvincing those religious arguments are in this day and age.
My personal experience would seem to show that, in Catholic, Muslim and JW families, the rate of remaining religious is closer to 75 to 80%.
One Catholic family whose child, at age 11, decided that his parents' adhererece to "a load of old superstitious bollocks" was not for him was dragged, fighting every inch of the way to Sunday Mass and, at the door of the church, became extremely loud in his protests at being dragged there to listen to "that old fart" (pointing to the priest welcoming the congregation) who talked nothing but a load of old cobblers.
The priest withstood the tirade for about five minutes before declaring that the child was clearly a lost cause as Satan had already claimed his soul and that he did not wish to contaminate his congregation with his presence, but would pray for his redemption.
He, the child not the priest, never again attended church of any Christian denomonation and, at sixteen, walked out of the family home and was treated as if he had never existed by the family.
An isololated case, but if it can happen once . . . ? And as this happened over thirty years ago I would agree that it is likely to happen more often now.