Beyond Mensa: How Triple Nine, Prometheus and Other High-IQ Societies Work

High IQ societies admit people by test score. Mensa takes the 98th percentile, the top 2%. The Triple Nine Society takes the 99.9th, about 1 in 1,000. The Prometheus Society takes the 99.997th, about 1 in 30,000. The Mega Society asks for one in a million. Each high IQ society’s own site states its line. Below: the lines side by side, which tests each one accepts, and why the rarer lines are less certain.

New here: the Prometheus Society’s own page says no test now being administered is approved for admission. The Miller Analogies Test it relied on was retired on 15 November 2023. It accepts only scores earned inside set dates, such as the Mega and Titan tests before 25 April 1999. The Mega Society’s own page lists 36 active members.

The further out this list goes, though, the shakier the underlying numbers get — not because anyone is being dishonest, but because of a limit this site has covered before: no test can reliably measure a score that rare. Every society here uses the exact same 98th-percentile logic Mensa does; what changes from one to the next is simply how far right on the curve the cut-off sits, and how much less trustworthy that cut-off becomes the further right you go.

Which high-IQ society fits an IQ of 127, 129 or 130?

Only Mensa is in reach, and only at 130. American Mensa’s lowest IQ lines are 130, so a 127 or a 129 meets none of the lines in the table above.

A 130 meets Mensa’s Wechsler line. It is 16.4 points short of the Triple Nine Society’s 99.9th percentile on SD 15. Our posts on an IQ of 127 and an IQ of 129 show how far each sits from the Mensa line. They also show why one point can come down to measurement error. For the claims about the top few percent, see whether an IQ of 130 is genius and how rare a high IQ score is.

What is Mensa's IQ threshold?

Mensa requires the 98th percentile on an approved, supervised test of intelligence. Nothing else about age, education or background counts. On the SD15 scale most modern tests use, that works out to about 131 (130.8). This site’s full breakdown of that number, and why different publishers report it as 130 or 132 covers the derivation. What matters here is the baseline: everything that follows is progressively rarer than the one high-IQ society most people have heard of.

Our Mensa IQ requirement explainer lists the line for each accepted test.

What is the Triple Nine Society, and what IQ does it need?

The Triple Nine Society takes its name from its threshold: “999” for the 99.9th percentile, about one person in a thousand. On the SD15 scale that is 146; on SD16, 149. Its own site says members scored at or above the 99.9th percentile on a test of adult intelligence. It names the GRE, the MAT, the Stanford-Binet and the Wechsler scales as examples. It calls that 20 times as selective as Mensa, and reports more than 2,000 members in 39 countries.

The number you need depends on the test. Its Test Scores page lists each accepted test with its own minimum score, and only those tests count. For example, it lists 36 for the ACT taken from 2009 onwards and 770 for the GMAT taken between July 2004 and January 2024. A 1-in-1,000 score is still rare. But it can come from a standard test such as the GRE or a Wechsler scale, not only from a specialist instrument.

What is the Prometheus Society, and which tests does it accept?

The Prometheus Society sets its bar at the 99.997th percentile: 160 on the SD15 scale, 164 on SD16, and roughly one person in 30,000. Its own site calls this four standard deviations above the norm. Here the practical requirements change. Its join page says no test that is now being administered and scored has been approved for admission. The last one, the Miller Analogies Test, was retired on 15 November 2023.

Prometheus still accepts documented scores from tests taken inside set dates. Examples are an MAT scaled score of 500 taken before 15 November 2023, a 36 on the Mega Test or the Titan Test taken before 25 April 1999, and an old SAT of 1560 taken before 1 April 1995. Most standardized IQ tests are not built with enough discriminating power that far out to certify a score that rare. That is the ceiling problem covered in why no IQ test can reliably score you above about 160.

What is the Mega Society, and why do its test scores go stale?

The Mega Society sits past Prometheus again, at the 99.9999th percentile — about one person in a million. Founded in 1982 by Ronald K. Hoeflin, it is a useful case study in what goes wrong at this level of rarity, and it is not merely a matter of statistics. Hoeflin’s own qualifying instrument, the Mega Test, ran unsupervised and untimed in Omni magazine in 1985 — anyone could take it at home, on paper, at their own pace.

That design made sense for reaching a geographically scattered population of extremely rare scorers, and it was also its downfall: once enough people had discussed the questions and shared answers, later scores stopped meaning what earlier ones had. The society stopped accepting Mega Test scores from after 1994, and a successor instrument, the Titan Test, was eventually retired for the same reason in 2020.

That history matters beyond one society’s administrative footnote: it is a second, independent reason — alongside the statistical extrapolation problem below — that scores this far into the tail are hard to trust at face value. A test rare and specialised enough to target one-in-a-million scorers is also, almost by construction, too small and too specialised in its niche to be administered under the same tightly controlled, regularly re-normed conditions as a mainstream instrument like the WAIS.

Its own site says it is open to people who scored at the one-in-a-million level on a test credibly claimed to discriminate at that level. It lists 36 active members as of October 2024. It names Hoeflin’s Ultra Test and Power Test as the tests added since the Mega Test and the Titan Test were retired.

Why do the numbers get shakier as a society gets more exclusive?

This is the important part, and it follows directly from that ceiling-effect article: a standardisation sample for a major test typically runs into the low thousands of people. That is plenty to characterise the middle of the distribution precisely, and it is nowhere near enough to empirically verify what a 1-in-30,000 or 1-in-a-million score should actually look like.

Past a certain point, a test manual is extrapolating the shape of a curve outward from data it does not really have, not reading a measurement off a ruler. That is exactly why the Mega Society, at the 99.9999th percentile — one person in a million — is not given a specific point-score equivalent here. Past a certain rarity, a single number claims a precision the underlying test data cannot support.

What do high-IQ societies actually do?

Beyond the admission threshold, the day-to-day reality of Triple Nine, Prometheus and similar societies looks a lot like Mensa’s: member newsletters, online discussion groups, occasional in-person meetups, and special-interest groups built around members’ other hobbies. The exclusivity is entirely in the door, not in what happens after you are through it — joining one of these gives you nothing functionally different from what Mensa already offers, just a smaller and more specifically selected room.

That is worth sitting with for a moment, because it cuts against the mystique these societies sometimes attract online. There is no secret curriculum, no exclusive research programme and no functional advantage to membership beyond the social one of meeting other people who cleared the same unusually high bar. For most people genuinely curious about their own score, an ordinary supervised test and a clear explanation of where the result sits on a standard scale will answer the actual question far more usefully than pursuing admission to any of these.

Should you try to qualify for a high-IQ society?

Only if you want the membership itself. A society gives you a community, not a credential, so check your score against each line first.

If you are curious, the realistic first step is the same either way. Sit a properly normed, supervised test and see where you land. An online quiz score tells you nothing about eligibility for any of these societies.

A casual, ungraded online test is not accepted by any of them. It should also not be read as an estimate of where you would land on one that is. The ceiling and norming problems described above apply to an unverified quiz just as much, with far less rigor behind the number it reports.

If you do not clear one of the higher bars, that says little about you. The tests that can tell the 98th percentile reliably were mostly never built to tell the 99.997th. These thresholds are about reasoning under test conditions, not how much you can memorize, a skill covered in this site’s piece on memory versus IQ.

For your own number, on a test that reports the scale, percentile and confidence range together rather than a bare figure, start here.

Quick answers

• What is the hardest high-IQ society to join? The Mega Society, which asks for a one-in-a-million result. Its own page lists 36 active members as of October 2024.
• What IQ do you need for the Triple Nine Society? A score at or above the 99.9th percentile on an accepted test: about 146 on SD 15 and 149 on SD 16 (our arithmetic). Each test on its Test Scores page has its own minimum.
• Is the Triple Nine Society harder than Mensa? Yes. It says its 0.1% line is 20 times as selective as Mensa’s 2%.
• Can an online IQ test get you into a high-IQ society? No. The Triple Nine Society accepts only listed tests with an official score report, and the Prometheus Society accepts only tests on its own dated list.
• Which society takes an IQ of 130? Mensa, on its Wechsler line. A 130 is 16.4 points short of the Triple Nine Society’s line on SD 15.

To see where a score of your own sits, take the IQ test, then place it with the IQ percentile calculator and the IQ bell curve.

Sources

• American Mensa. Qualifying test scores (page read 14 November 2026).
• Triple Nine Society. What is TNS? and Test Scores (pages read 14 November 2026).
• Prometheus Society. Home and Join or Subscribe (pages read 14 November 2026).
• Mega Society. The Mega Society, including its history section (page read 14 November 2026).
• The score equivalents, the 130.8 line and the 16.4-point gap are our arithmetic on a normal curve with mean 100; they are not published by the societies.