But on a more serious note, you might want to read Jeffrey Shulman's Sacred Trust or Sacred Right? (download here). Cribbing from his abstract:
It is commonly assumed that parents have long enjoyed a fundamental legal right to control the upbringing of their children, but this reading of the law is sorely incomplete. What is deeply rooted in our legal traditions is the idea that the state entrusts parents with custody of the child, and the concomitant rule that the state does so only as long as parents meet their legal duty to take proper care of the child.One might wonder who entrusted parents with authority before the rise of the modern state but Shulman would probably believe the answer of antiquarian interest only. Now it is the modern Enlightenment state in whose view "the law of parent-child relations has long embodied a belief that education (a 'leading away from') is the path away from childhood and toward intellectual and moral enfranchisement."
Shulman's view is consistent with the father of the English Enlightenment, John Locke, so it's no surprise it has come to dominate the current legal understanding of the parent-child relationship.