Isn't that a neat little way to dismiss anyone who's + that doesn't fit into the the-o-ry, especially since the Rh factor was only discovered 60 years ago so most of us can't trace it back more than a generation or two. What about countries where the Rh- is so rare it's almost non-existent? Does no one there share these "traits"?

I can tell you that both my parents are positive and that neither set of grandparents or great-grandparents had any pregnancy problems resembling Rh incompatibility.