I'd never come across this until a few months ago on a training course and I could have misunderstood things, after all, it was only one person's interpretation of the method but it just seems so old fashioned. OK, I'll say it. I think it's bunk.
I have never, ever in my life applied this parent, adult or child in the situation theory unconsciously or naturally and can't think of how I could apply it in the future as a helpful strategy.
Maybe somebody can help me out here and tell me what I've missed?