MENSA, the élite international high-IQ society, was founded in Oxford during 1946 as a third pillar intended to complement the Royal Society and British Academy. There is but one single requirement to be invited to join MENSA: an individual must have an IQ that is measured to be among the top two per cent of the population. But what is MENSA, and what purpose does it serve? The purpose of this book is to critically examine this ‘origin myth’ of Mensa in light of evidence from publicly accessible primary sources. Of particular interest is the stated aim of MENSA’s three acclaimed founders for the society to conduct research that would or could inform decision-making by government and other authorities.