Wonder no more... They start early and often using any free moments to convince their children that ayn rand wasn't a hypocrite for living off social security when she died.
Often they don't, since save for a small number of moderates among them that are actually mostly decent on this topic or even have somewhat progressive views on the subject, they either believe children are property thus the parents can do anything they wish to their children, have all sorts of excuses and conspiracy theories about why people with common sense doesn't let them abuse their kids (won't go into it, I'm already mentally scarred by reading about it, curiosity killed the cat), or limit their interest for teens under the guise of all sorts of excuses (supposed enough mental maturity, thinking the issue stems from "undeveloped bodies", etc.).