Society Directory

The recognized full-membership list by the USIA is from 2 sigma to 5 sigma, in which “sigma” applies to “S.D.” or standard deviation. For example, Mensa = 2 sigma (1:50 or 1-out-of-50 in the general population), when S.D. equals 15, 16, or 24 , means 3 times 15, 16, or 24, plus 100, or 130, 132, and 148, respectively. Please make sure the list is for the reference of the official USIA Qualifications.


2 Sigma (Standard)
IQ 132, SD16 Mensa
IQ 137, SD16 Intertel
IQ 137, SD16 Top One Percent Society
3 Sigma (Standard)
IQ 148, SD16 Three Sigma Intelligence Society of USIA
IQ 149, SD16 Triple Nine Society
IQ 150, SD16 One in a Thousand Society
4 Sigma (Standard)
IQ 164, SD16 Four Sigma Intelligence Society of USIA
IQ 164, SD16 Prometheus Society
IQ 164, SD16 Epimetheus Society
IQ 176, SD16 Mega Society
IQ 176, SD16 Omega Society
5 Sigma (Experimental)
IQ 180, SD16 Esoteric Sigma Intelligence Society of USIA