It seems obvious on the face of it to me, and, I suspect it did to you, before you let someone try to get clever about it.

What it does leave out, though, and where some - if not cleverness, mental flexibility - is required, is that those are just boxes, and not all individuals fall neatly into the boxes. That, too, is not simply memetic.

Also, animals can have memes. See the recent article about baboons - http://lesswrong.com/lw/99t/can_the_chain_still_hold_you/