Q: When she is happy or receiving a lot of my attention, my 12-year-old daughter often speaks in "baby talk." Examples: "I wub you" and "You my mommy." When she's in one of these moods, she constantly asks for hugs and kisses and then, if I tell her I'm busy, she whines. After a while it's infuriating and I want to get away from her. I've tried talking to her about it, but to no avail. Have you heard of this before? How can I get her to stop?
Yes, I've heard of this before. I've heard everything, in fact. This is known as "post infantile articulation thrombosis." It's a very rare condition that can be cured with repeated beatings with foam rubber baseball bats, but if you don't like that idea...
Sit down with her and clearly define the problem, as you see it. Don't pull any punches. Be clear, concise, and use examples. Tell her that her baby talk eventually becomes very annoying to you and that on any given day, when you reach your limit of baby talk, you're going to tell her, "I've reached my limit for today."
And by the way, your limit can be one time. That's your parental prerogative. From that point on, every time she crosses the line her bedtime is backed up by 30 minutes because "this sort of immature behavior indicates to me that you aren't getting enough sleep."
Then, follow through. If you can manage to be dispassionately consistent, her PIAT should be cured in about four weeks.