It’s official. The “Harlem Shake” has taken over the world. The song, by New York music producer Baauer, recently hit the No. 1 spot in the iTunes store. What started as a strange YouTube video of several friends dancing in masks and spandex bodysuits has somehow become a cultural phenomenon, with sports teams, firefighters, office workers and even schools all contributing their own versions of the video with ample amounts of thrusting, mask-wearing and Harlem shaking. Ironically, this news comes on the same day that a Stanford University researcher has released new data showing that human intelligence is on a slow but steady decline …