Children develop in many different ways, from platelets to apoptosis. I'm assuming you mean something like cognitive development. However, it takes children many years to be able to reflect upon their conceptions of self and prior to their capacity for doing so they generally require a worldview wherein which much of the structure is provided. And whatever Dawkins and the New Atheists may argue, the fact that parents with particular political ideologies do not necessarily tell or label their children according to their views matters little when they do impart at every election who should be elected and why and communicate in many ways their political worldviews. I recall every year growing up, but especially those years in which there was a presidential election, we children talking about who should be elected and teachers creating mock voting booths. In the end, most simply regurgitated their guardian'(s') view(s) and could not defend their positions (nor should they have been expected to.
Cognition is thoroughly influenced, down to basic reasoning, by culture. To imagine a world in which children can be raised without dogma is to be blind to the dogma that is imposed upon one simply by virtue of the sociocultural contexts, language, SES, and other factors that influence things so seemingly unrelated as the notion of fairness or spatial cognition.
Yet they frequently self-identify as such. Nor is the identification of one as an American, Canadian, Russian, etc., much different. In fact, for a child to identify herself or himself as Jewish need not entail any religious beliefs. I remember in kindergarten and first grade before I had any knowledge of race that we were all just kids. Then we were informed about Martin Luther King, segregation, and other horrors that Americans have sought to assign to a distant past to readily. Yet once we learned of such distinctions the formed part of our identities, and I recall one day in particular noticing as I went out to the cafeteria that it looked nearly like a chess board: tables of those who were black and those who were white, but little if any tables at which both sat (until I turned 14, I grew up in a town that was almost entirely white, but there was a program set-up to bus black children from Boston into schools in the suburbs).
It would be wonderful if we could hand children Plato, Descartes, Confucius, Kant, Nietzsche, Hume, Aristotle, Plantinga, Thomas Aquinas, Anslem, Freud, etc., and just say "read up". This isn't how it works. Upbringing entails indoctrination.
I was raised Catholic and have been agnostic so long I don't remember what it was like to believe, but I think my fathers' showing me Cantor's proof that some infinities are bigger than others when I was about 6 was far more damaging than any experiences in Church. Also, for good or ill, it is simply a fact that Western culture is thoroughly steeped in Christian thought from the creation of the university system and early modern science to basic moral and ethical notions. Being blind to what forms one's worldview is not an advantage.
Societal standards are defined by pressure to conform. Most children care far less about whether they are Pentecostal, Eastern Orthodox, or neopgan than whether they like the "right" bands and wear the "right" clothing.
Human nature does that.
Henrich, J., Heine, S. J., & Norenzayan, A. (2010). T
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And no doubt such open-mindedness as you express would be invaluable to a child's ability to freely determine her or his own worldview.