I think there's only a very few things that are universal (I'd have to pick that book up again), but what I'm trying to say is... it's FAR easier to control the more visible parts of body language (seeing to the eye, etc), than it is to control parts of the body language we're much less conscious of. Many of us will learn to control our hand gestures, our eyes and our face to an extent. But not all of us will think of including the feet in that. So it may not be universal that turning one's feet towards someone means interest... but it's more common than people looking at you meaning interest. And at any rate... whichever body language is displayed requires the context to be properly interpreted. There was this book called "What Every Body is Saying" that had some really nice tips about how to use context to interpret body language.