http://www.naeyc.org/files/yc/file/201201/Leong_Make_Beli... This article discusses different steps in make believe play. Scripting and planning to do the script is the highest level according to this theory.
http://www.toolsofthemind.org/parents/make-believe-play/. I just looked this up to find more answers about what I said below. I think the key is to find more kids to play with.
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I've been trying to figure out how to word a question about this myself. I am greatly relieved to hear that other kids do this, too. I don't know about the OCD messages in the forum here. I'm going to reflect on that.
My DD does this almost daily with both my DH and I. She's an only and she's seven years old. In my mind, I'm typically thinking, "She needs a kid right now for peer interaction." She wouldn't get away with this with her peers. Being an only, there are not necessarily times I can conjure up a child for her to play with.
I think the play is terribly creative, but I do get tired of it, and I tell her when I am done. Sometimes I do not tell her in time, and I have become quite annoyed. Sounds like it is time to set some ground rules (I'm talking to myself here!)
She now has extended it to directing a play or thinking about filming the play. I see that it can be great for her to do this because movie making is a solid career choice, so I don't want to squash this type of play, but I need to extract myself from being the actor at the director's whim.
DD is able to entertain herself, but she also likes to be with people and talk. This is why I participate in this play direction game. Yes, she does it with stuffies, too, but since she likes to talk to people, I try to fulfill that need of hers. I aksi try to find an activity both of us want to do at the moment when I tire of that type of playing.
Maybe our kids are trying to figure out how conversation works. As an only, I observe her talking with kids, and at times I observe natural conversation, and at other times I observe her trying to figure out what people would say. I don't know. I'm in the middle of figuring out this behavior myself.
I suspect Steven Spielberg did this, too.