DW befriended a new mom, and in sharing parenting styles, the new mom declared we must be AP parents... and DW said, "What's that?"

Long story short, we got some literature on the subject, nodded our heads at some parts, but openly rebelled at others, and declared ourselves definitely NOT AP parents. The major issues we had were the lack of boundary setting and the permissive disciplinary style. So far, it sounds like a lot of the self-identified AP parents in this thread had the same issues, and just decided to do that a different way.

As for the original question... depends on what you mean by "discipline." Individual responses will vary. The research says discipline done wrong (authoritarian) will break a child's spirit, and lack of discipline (permissive) will do it, too.