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. The word mensa (/ˈmɛnsə/; Latin: [ˈmensa]) means “table” in Latin, as is symbolized in the organization’s logo, and was chosen to demonstrate the round-table nature of the organization; the coming together of equals
Mensa’s constitution lists three purposes: “to identify and to foster human intelligence for the benefit of humanity; to encourage research into the nature, characteristics, and uses of intelligence; and to provide a stimulating intellectual and social environment for its members”.
To this end, the organization is also involved with programs for gifted children, literacy and scholarships, and it also holds numerous gatherings.
Mensa’s requirement for membership is a score at or above the 98th percentile on certain standardised IQ or other approved intelligence tests, such as the Stanford-Binet Intelligence Scales. The minimum accepted score on the Stanford-Binet is 132, while for the Cattell it is 148. Most IQ tests are designed to yield a mean score of 100 with a standard deviation of 15; the 98th-percentile score under these conditions is 131.
Mensa also has its own application exam, and some national groups offer alternative batteries of tests. These exams are proctored by Mensa and do not provide a quantified score; they serve only to qualify a person for membership. In some national groups, a person may take a Mensa offered test only once, although one may later submit an application with results from a different qualifying test.