[Parapetenia]

I assume by Stevie Wonder thing, you mean he sways back and forth. This is typically excited and happy body lauguage. He probably is doing this to show how much he enjoys hanging out with you, and wants more.

Peach and Pedro do this all the time. I often refer to it as dancing. They really start doing it when music they like is playing(Black Sabbath, Prince[for the birds, not me], etc.). It's amazing how precisely they can move to the beat.