What Is the Thomas GIA Test?

The Thomas GIA, short for General Intelligence Assessment and also branded the Thomas Aptitude assessment, is a speeded cognitive test from the UK publisher Thomas International. It runs five short subtests, each lasting two to five minutes, about 30 to 45 minutes in all with instructions, and combines them into a single General Trainability Index that employers read as a measure of how quickly you can learn a new role. This article covers the five subtests, the research behind the test, what the scores mean, and how a trainability index differs from an IQ score.

The official example booklet describes five point-and-click tasks, each preceded by eight practice items. Speed and accuracy count equally:

• Reasoning: Read a statement such as "Bob is not as happy as Paul," watch it disappear, then answer a question about it ("Who is sadder?"). It measures deductive reasoning and short-term memory together.

• Perceptual Speed: Count how many of four letter pairs match, as fast as possible. A pure error-checking task.

• Number Speed and Accuracy: Given three numbers, pick the one furthest from the middle value. Basic numerical reasoning under time pressure.

• Word Meaning: Pick the odd word out of three. Verbal knowledge at speed.

• Spatial Visualisation: Decide how many symbol pairs are rotations rather than mirror images. The vendor notes this correlates well with mechanical reasoning tests.

Thomas does not publish question counts per subtest, because there is no fixed count: you answer as many items as you can before each clock runs out. Prep-site tables quoting exact counts are guesswork.

The GIA is unusually well documented for an employment test. Thomas's own science summary says it derives from tests originally released in 1992 after six years of research, citing the work of Sid Irvine and Peter Dann, the University of Plymouth researchers whose programme also produced the British Army's recruit selection battery. The theoretical framing draws on Carroll's three-stratum model of intelligence and on working-memory accounts of trainability. Thomas states the assessment has been independently audited by the British Psychological Society, and its published validity studies report correlations of .30 to .51 with military training performance and large score gaps between promoted and non-promoted telecom recruits. The company says more than 11,000 businesses use its assessments.

It is closer to one than most employment screens, and still not one. The GIA samples real components of general intelligence, and its "trainability" construct is essentially fluid ability plus processing speed. But it is heavily speed-loaded in a way clinical IQ batteries are not, and it returns a General Trainability Index against occupational norms rather than an IQ score; Thomas publishes no public norm tables, so prep-site percentile charts cannot be checked. It sits in the same family as the Predictive Index and the Wonderlic: fast, defensible, and narrower than a full battery. If you want the full-battery answer, the Reasoning and Intelligence Online Test from RIOT IQ measures six abilities separately with real norms, and you can take a free IQ test to see your profile.

Each of the five subtests lasts two to five minutes; the whole assessment, including instructions, takes about 30 to 45 minutes.

Five areas: reasoning, perceptual speed, number speed and accuracy, word meaning, and spatial visualisation, combined into a General Trainability Index.

Thomas does not publish public norm tables. Scores are norm-referenced, and employer cutoffs vary; specific percentile tables on prep sites are unverifiable.

Yes. Thomas provides a free official example booklet with sample items, and each subtest opens with eight practice questions.

The items are simple; the speed is not. The test is designed so nobody finishes comfortably, which is how it spreads people out.

1. Thomas International. (2024). The science behind the Thomas Aptitude assessment [PDF]. thomas.co

2. Thomas International. (2018). GIA example booklet [PDF]. thomas.co

3. Thomas International. (2026). General Intelligence Assessment (GIA). thomas.co

4. Irvine, S. H., Dann, P. L., & Anderson, J. D. (1990). Towards a theory of algorithm-determined cognitive test construction. British Journal of Psychology, 81(2), 173-195. doi.org/10.1111/j.2044-8295.1990.tb02354.x