Guide · fluid intelligence

A fluid intelligence test you can take today

Fluid intelligence is reasoning with what is new: finding the hidden rule, checking it against the evidence, and changing your mind when the evidence changes. Every Resquites test measures it with original problems, and two of them give you a score today: THETIS, adaptive, and RUFIT, timed.

Take THETIS Take RUFIT Practice puzzles

What a fluid intelligence test measures

A test of fluid intelligence gives you material you have never seen and asks you to make sense of it: what rule turns one panel into the next, what a set of verdicts says about a hidden sorting rule, where a boat must moor given the rules. Knowledge does not help, so the test measures reasoning itself rather than what schooling or reading gave you.

THETIS goes one step further and measures abductive–dynamic reasoning: inferring a rule from evidence, testing it, and noticing the moment the rule has changed. Its puzzles come from eight families, and the report shows a facet score for each.

Without words. Fluid reasoning is best seen in material that is new to everyone, which is also what makes a test fairer across languages and schooling. More on culture-fair tests.

Two ways to measure it today

Adaptive · a generous clock on each puzzle
THETIS
About 30 original puzzles (20 to 45), each chosen by item response theory for your current estimate, with 3 to 20 minutes for each. A practice module of 16 puzzles comes first. Your IQ (SD 15), its 95% range, percentile, facet scores and a verifiable certificate appear the moment you finish; it measures with much the same precision from about IQ 55 to 200. US$19.99 per session, and you may take it again with new puzzles.
THETIS
Timed · 36 questions
RUFIT
36 original figural and numerical questions with eight choices each, 35 or 60 seconds per question, about 29 minutes in all. Scored with a norm published in 2021 from 266 valid submissions (internal reliability .92), with an instant certificate. US$50, one attempt, including the review of a society application.
RUFIT

For the gifted range and beyond, the untimed tests give each problem as long as it takes: high-range IQ tests. How THETIS is scored, and how precise it is, is set out in its technical manual.

Questions

What is fluid intelligence?

The ability to reason with new material: to find the rule behind a pattern, test it against the evidence and apply it, without relying on what you already know. It is usually set against crystallized intelligence, the knowledge and skills built up over a lifetime, a distinction that goes back to Raymond Cattell.

Can practice raise my score?

Knowing the format helps, which is why THETIS opens with a practice module of 16 puzzles and RUFIT shows its format before it begins. Beyond that, a fluid reasoning test uses problems you have not seen: THETIS never repeats a puzzle, or a close variant, for the same person.

Timed or untimed: which is better?

They measure slightly different things. A timed test such as RUFIT adds speed of reasoning; a power test such as THETIS gives every puzzle time enough that speed hardly matters; the untimed high-range tests allow days for the hardest problems. Taking two kinds gives the fuller picture.

Is an online score an official IQ?

No. The Resquites tests are unsupervised online tests of fluid reasoning, with norms that are published or labeled provisional. They are not clinical or diagnostic assessments; for an official score, take a supervised test given by a licensed psychologist.