Many of us have -- or at some point want to have -- children, and wonder how we can do our best to fulfill the "nurture" component of helping them develop mathematical talent... not because we want them to be mathematical professionals, but we'd like them to have the choice, like we did.
However, this is not a question about how one "should" raise children, because of how fiercely debatable even the meaningfulness of such a question would be. Instead,
What reputable statistics are known about how mathematicians or highly mathematically talented people have been raised, especially during their early, formative years when "potential" is thought to be more of a variable?
(This question is community wiki, so everyone can edit it.)
Edit: I changed the title from "How are mathematicians raised?", since I personally only intended to ask for descriptive, not prescriptive, answers. The "However" paragraph above was inserted to further emphasize this.