This is (I think) one of the strangest phenomena that the social sciences have uncovored. I highly suggest everyone read this article
Linky and maybe this
other link
Not only does this seriously question the validity of the assertion that IQ tests test "innate intelligence," it also really alters the conception of what intelligence is.
Also, it really drives home the interconnectedness of a people, since, evidently, there is a type of group learning taking place on a very large scale.