It's a lofty title, yes, but I do like these helpful diagrams from RGA (via Giles Rhys Jones) showing the progression from communication to "systems of interaction". Social design would, I presume, fit within the experiences section; that is to say, designers don't create experiences, they create 'artifacts to experience, and do so in an increasingly social context.
This is an interesting area for planners/strategist to play, as social design and experience planning bridges the world of technology, digital media and our social (herd) nature (if you're into that sort of thing).
Here's another helpful way to think about it.
I like it, especially because the little Tech Lead guy is thinking about "something totally unique".