According to Dr. Win Wenger, author of 48 books including How To Increase Your Intelligence and The Einstein Factor, we can all gain 10 or more IQ points if we accumulate 20 hours of held-breath underwater swimming in doses of 20-180 seconds at a time over a 3 week period. Including better span of attention, better span of awareness, better awareness of the interrelatedness of things and of ideas and/or perceptions, and better ability to win arguments and disputes. How can we not love this theory, especially when he stresses that this has to be truly underwater – not just holding your breath or dipping your face in water – since the brain-circulation enhancement apparently is induced by the marine diving response. Via this article on Institute for Ethics and Emerging Technologies, also mentioning six other ways of improving your intelligence.