This advertisement has appeared in several journals of high-I.Q. societies in 1997 or shortly thereafter, probably OATH, Thoth and Noesis. It was also a parody on the advertisements of the International Society for Philosophical Enquiry and Intertel at the time, which read something like: "Do you qualify for the ISPE?", and "Be part of the international 1% group. (not affiliated with Mensa)".
