Mensa International is a non-profit society consisting of high IQ people. To be admitted to Mensa, an applicant must score at or above the 98th percentile on a standardized IQ test under supervision. (By definition only 2% of those who take a standard IQ test attain 98th percentile.) The typical IQ tests are normed so that half of the people who take the test score at or below 100 and the 98th percentile corresponds to an IQ score of 131.
American Mensa administers its own test, rather than one of the standard IQ tests, but it also requires a score at or above the 98th percentile for admission to the society.
