AMPHITRITE: the adaptive fluid reasoning test

An untimed, adaptive online test of fluid reasoning, from the AMPHITRITE research edition A03 (28 October 2026), for ages 16 to 80. Its twelve families of visual problems ask you to combine scattered clues, undo hidden operations, compose two rules, match roles across worlds, decode recoded strips, compare worlds of commands, satisfy constraints, repair an arrangement, read nested conditions, follow an intervention through gates, find what never changes and choose the decisive evidence. Every problem has four choices, and an independent computer check confirmed that exactly one of them is valid under the problem's rules for every problem in the bank: the 2,400 practice problems and the 18,196 scored problems that can be given.

It opens with 12 practice problems, one per family. Answer each and lock it: you see at once whether you were right, the right answer and the reasoning. Practice is never scored. Then the scored problems come one at a time, each chosen from your answers so far: the model picks, among the families you have met least, the problem that tells most about your level, for 40 scored problems; from level 5 up, a level opens only once you have solved the one below it consistently. Choose one of the four answers, numbered 1 to 4, and lock it; a locked answer cannot be changed, and you cannot go back. Every scored problem must be answered: a guess is better than none. Nothing tells you whether a scored answer is right, and your result appears the moment the last one is locked.

Every family has eight construction levels, with model difficulties of IQ 55, 75, 90, 105, 125, 150, 185 and 225 from level 1 to level 8. Edition A03 (28 October 2026) rebuilt the two top levels of every family, and every level of Recoded worlds and Decisive evidence, so that the construction itself grows with the level. A problem at level 7 or 8 cannot be solved by following its clues one at a time: it needs a hypothesis tested against the conditions, several conditions combined that settle nothing alone, or a structure followed several steps deep. Its wrong choices are near misses built to survive a quick check: each breaks only one condition, follows from a single slip, or agrees with the right answer on everything a glance can check. The IQ values of the levels are still the model's assumptions: they become measured difficulties only once real first attempts are analyzed.

From the problems you were given and your answers to them, by the provisional model AM-M01: each problem has an assumed difficulty from its family and level, and the model's estimate of your ability is shown as an IQ (mean 100, SD 15) with its 95% interval. Two people with the same number of right answers can receive different problems and different results. AMPHITRITE is a research edition: no human calibration has been done yet (N = 0), so a score is a provisional position on the model's scale, not a percentile of the population, and no percentile is reported. The scale reaches IQ 225+, a research target rather than an established ceiling; above about IQ 195 a score ranks performance on this test only. An estimate below IQ 55, the level of the easiest problems, is reported as below IQ 55. Beside the IQ, as THETIS does, your result gives the rule complexity: the construction level, from 1 to 8, of the problems you solve half the time beyond chance. It describes what you solved, so it depends on no population norm.

A high score must rest on consistent success at the levels below it (the ladder, from 5 November 2026, as THETIS has above IQ 180). From level 5 up, AMPHITRITE climbs one level at a time: no problem above the level being cleared is given until it is solved consistently, which takes at least three right answers at that level, from at least two families, with at least two in three of its problems right; very consistently, from 160 up, at least four right, with at least three in four of its problems right. So a score of 135 or more needs level 5 (problems of IQ 125) solved consistently, 150 or more level 6 (IQ 150), 160 or more level 6 solved very consistently, 190 or more level 7 (IQ 185) very consistently and 225+ level 8 (IQ 225) very consistently. Until then a score is held just below the next step, however well the answers above it went; the result and the certificate say so.

AMPHITRITE is untimed. From the moment you begin, your attempt stays open for 90 days: work in as many sittings as you like, on any device, with your private link, and you come back to the problem you left. Each answer is locked on the server as you give it. An attempt still open after 90 days is scored with the answers locked by then, provided it has at least 24 scored answers; otherwise it ends without an IQ.

Yes, whenever you like once your previous attempt is finished, and every attempt is on problems you have never been shown. Every problem counts as seen the moment it reaches your screen, together with every variant built on the same rule, under this email or another registered with the same name and year of birth; no later attempt meets it again. Practice gets new problems too, while they last. Every attempt has its own fee and its own certificate. Register every attempt with the same email. Only first attempts go into the research data on the test's norms.

The US$19.99 fee, paid through PayPal before the attempt opens, covers one attempt: the practice problems with their explanations, the 40 scored problems, your result with its PDF certificate, and a copy by email. Each retake has its own fee.

Yes, from 5 November 2026. IQ 147 or higher meets the criterion of the Nereid Society, IQ 160 that of the Mesopelagic Society (with a one-time membership fee), and IQ 190, 205 and 220 those of the Aphotic, Hadal and Exocosm Societies. Just below the criteria, IQ 135 to 146 qualifies for associate membership of the Nereid Society and IQ 180 to 189 for subscription to the Aphotic Society, each with a one-time admission fee. Your fee includes the review of one society application. Your best result counts, as for THETIS, and it counts as AMPHITRITE's ladder holds it: a high score must rest on consistent success at the levels below it (see “How is my score worked out?”). AMPHITRITE is a research edition, scored with provisional model norms until enough first attempts are in, and the author reviews every result before admission.

To build AMPHITRITE's norms from real people. They are re-estimated from first attempts only, anchored on examinees whose IQ is known from a supervised test, such as a Wechsler or Stanford-Binet scale given by a psychologist, Raven's or Cattell's test given under supervision, or a high-IQ society's supervised admission test. Giving yours is optional, and it never changes your own result: it only helps place the problems on the IQ scale for everyone. Only attempts with a clean integrity record are used, and a new calibration is applied only when, checked on people it was not fitted on, it comes closer to their known IQs than the scale in force. If you allow it, the author may write to you to confirm the score.

The answer keys and the bank never leave the server, and your result never shows which scored problems you solved. Only the problem on screen ever reaches your browser: the next one is chosen on the server after you lock your answer, from the answers you gave, so there is no list of problems to look up in advance, and a retake is always on problems you have never been shown. Each problem is drawn on the screen with a faint watermark of your name and certificate ID. While a problem is on screen, the test page records leaving the test window, screenshot shortcuts (Print Screen, Windows+Shift+S, Command+Shift+3, 4 or 5), printing (Ctrl+P or Command+P), copy, right-click and drag attempts, and AI assistant add-ons that insert themselves into the page; the server keeps its own times (when each problem was shown and when its answer was locked) and notes right answers given moments after a long absence, and many right answers in a few seconds. As on THETIS, it checks the answer pattern against the difficulty of the problems you were given (a pattern unlikely for one person at your level is noted, as is a result at the top of the scale), and practice problems are recorded too. The record is sealed when you finish, and its fingerprint is printed on your certificate. The author's integrity report of each attempt lists all of it, problem by problem. None of this changes a score, and unusual results are reviewed, never judged automatically. An untimed test cannot rule out every form of help, which is why you declare that you will work alone.

Your private link (shown when your test is ready, and kept in this browser) reopens your test on any device, at the problem you have reached. If you lose it, use “Recover my test” with the PayPal Transaction ID from your receipt and the email you registered with. Every locked answer is on the server.

Yes: the twelve example problems above, one per family, with their answers and solutions. They are never used in the test itself, nor is any variant built on the same rule.