In the Spirit of Collegial Inquiry...

Group Statistics

Mean IQ: 144.9, s.d.= 4.8 *

Mean age: 41.3, s.d.= 12.2

Ages range from 17 to 70, with mode of 44 and quartiles at ages 33, 41, and 48 (based on available member data in February, 2000). An interesting observation: women constitute a small segment of the membership, but are disproportionally represented in the upper quartile. The mean level of formal education is 16.5 years, sd= 2.5; approximately 40% hold at least one masters degree, with 15% PhD, JD, or other doctorates. Law, engineering, computing, and the physical sciences are prominent among career choices. As the personal profiles reveal, there is a wide range of occupations, interests, and specialized talent within the context of mental ability.

Countries and cultures represented: Australia, Belgium, Brazil, Canada, China, Croatia, France, Germany, Great Britain, Greece, India, Italy, Japan, Korea, Mexico, New Zealand, Pakistan, Romania, Russia, Spain (Catalunya), Sweden, United Arab Emirates, United States (incl. African-American), Vietnam ... Apologies to members for any omissions!

Distribution of Member Scores

calculated from consecutive candidate score submissions, Jan 1998 - May 2000, n=100.

IQ*z-scorepopulation %ileColloquy %ileremarks

The Graduate Record Exam (20%), Scholastic Aptitude Test (15%), Wechsler Adult Intelligence Scale (10%), Miller Analogies (9%), Raven Advanced Progressive Matrices (7%), and California Test of Mental Maturity (7%) have been the instruments most frequently used in qualifying for membership in Colloquy. About 20% of the candidate tests were administered through Mensa, and overall, about 50% qualified via graduate or undergraduate academic tests and 50% by IQ tests per se. Several members presented comparable scores of both genres.

As a common format, these tables use a Gamma scale* IQ with s.d.=15.53, percentile 99.5 defining 140 IQ.
This reasonably approximates the most frequently-encountered SDs between fifteen and sixteen points. Among other advantages, the two most common "confidence interval" benchmarks fall at 130 and 140 IQ, respectively. In many Gifted and Talented educational programs, the 130 IQ level is regarded as a threshold of intellectual giftedness. As a rule of thumb, ten-point differences are likely to represent noticeable differences in mental ability among individuals, while differences of twenty or more points typically present some barriers to effective communication. One could debate that point, considering that perceived differences also arise from differing patterns of individual strengths and weaknesses, even among those sharing similar full-scale IQ scores. Those are the very differences which contribute such intriguing depth to intragroup exchanges.

It is reasonable to suggest that there may be some understatement of the " true " scores of some members owing to the ceiling limitations of several of the supervised tests used for qualification. This is particularly a concern with scores derived from the GRE and similar academic measures. WAIS and the Cattell Culture Fair are probably the only tests covering the full range of scores indicated in the table. In fact, ongoing review of the available tests suggest that scores above the 99.99 percentile are rarely encountered or attainable in the realm of standardized testing for adults ... and certainly questionable on experimental tests.

* The standard deviation and mean of the Otis-Gamma test are, for practical purposes, the same as those used here. Besides, it evokes a smile in the association with Huxley's famed novel. Irresistible!

Table of tentative IQ conversions for qualifying scores (140 - 149)

Table of tentative IQ conversions for qualifying scores (150 - 159)

Table of estimated general population means and SDs for several tests

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