"I guarantee, if you home school your kids for eight hours a day every day, they’ll be in college at age 12, too."

So says a mother, presenting a conundrum: I'd be inclined to say that you can't make such a huge inference based on the experience within your own family, since you don't know what part of the achievement is based on the teaching method and what part is the skill of the parent and the inherited ability of these children. And yet if the skill of the parent and inherited ability are an important part of the daughters' achievement, why does the mother lapse into this huge inference and make a grossly unsupported guarantee?