Mensa International

Mensa is the largest and oldest high-IQ society in the world. It is a non-profit organisation open to people who score at the 98th percentile or higher on a standardised, supervised IQ or other approved intelligence test. Mensa formally comprises national groups and the umbrella organisation Mensa International, with a registered office in Caythorpe, Lincolnshire, England, which is separate from the British Mensa office in Wolverhampton.