Mensa is the largest and oldest high IQ society in the world. It is a non-profit organization open to people who score at the 98th percentile or higher on a standardized, supervised IQ or other approved intelligence test. Mensa is formally composed of national groups and the umbrella organization Mensa International, with a registered office in Caythorpe, Lincolnshire, England. Mensa Denmark is the local Mensa Chapter in Denmark.