The
Triple Nine Society (
TNS), founded in 1978, is a 501(c)(7) non-profit
voluntary association of adults who have scored at or above the 99.9th
percentile on specific
IQ tests (or similar) under supervised conditions, which generally corresponds to an
IQ of 149 or greater using a standard deviation of 16 (e.g. Stanford-Binet IV, CTMM), 146 or greater with a standard deviation of 15 (e.g. WAIS-IV, Stanford-Binet 5, Raven APM, RAIT), and 173 or greater with a standard deviation of 24 (e.g., Cattell III-B). This compares with
Mensa International, the better-known and larger membership
high IQ society which admits applicants who score at or above the 98th percentile, which generally corresponds with an IQ score of at least 130 (SD 15), 132 (SD 16), or 148 (SD 24).