Aptitude tests and job interviews: a pairing every candidate knows, but how much do those tests really count? A new analysis published in the Journal of Business and Psychology scales back the weight of general mental ability, the kind measured by classic logic and reasoning tests, in predicting how someone will perform once hired.
For decades, work psychology regarded general mental ability as the best single predictor of job performance. The major syntheses of the past pointed to corrected correlations close to 0.50, a very high value for the social sciences. The study by Saron Demeke, Paul R. Sackett, Christopher D. Nye, Yujia Li and Nathan R. Kuncel, published in August 2026, reaches a much lower estimate.
What the study measured
The authors pooled data from three recent meta-analyses, covering research carried out between 1990 and 2022, removing overlaps and reanalysing everything together. Here are the main figures, as reported in the article's abstract.
- 212 independent samples analysed, totalling 109,396 workers.
- 1990–2022: the period covered by the included research, while historical estimates relied largely on data collected before 1980.
- Between 0.16 and 0.23: the correlations reported by the three original meta-analyses, taken one by one.
- Between 0.18 and 0.22: the average validity of general mental ability for overall performance, across the study's different analyses.
- 0.20: the summary estimate the authors propose as the contemporary value, against roughly 0.50 in traditional estimates.
A figure measures one thing only, and it's worth reading it precisely: a correlation of 0.20 doesn't mean intelligence doesn't matter. It means that, on its own, it explains a limited part of the differences in performance between people. The authors themselves make this clear: the results do not indicate that general mental ability is unrelated to job performance.
Not just complexity: the type of job changes the picture
The study also checked whether the weight of the tests changes with the characteristics of the job, using the classifications of the US occupational database O*NET. The result runs against a widespread idea: the cognitive complexity of a role and its interpersonal component show little relation to test validity. The link appears stronger instead in jobs with a manual and technical component, and in those combining cognitive and manual activities.
In other words, reasoning tests are not necessarily more predictive for the most intellectual or people-facing roles. The authors recommend presenting recent results separately from those collected in past decades, because work and the ways of assessing it have changed.
Aptitude tests in job interviews: what changes for candidates
For anyone going through a selection process, this research suggests a more balanced reading. Aptitude tests remain a widespread tool and should not be underestimated: practising logic exercises, time management and careful reading of instructions still makes sense. But the test doesn't tell the whole person, and more and more companies combine it with other assessment steps.
The interview, in particular, remains the place where qualities a score cannot measure come through: the way you listen, the clarity with which you describe your experience, the consistency between what you say and what you show. If the weight of a single test shrinks, the importance of everything else grows accordingly.
What recruiters observe
The study doesn't measure the weight of communication or image, and shouldn't be stretched in that direction. It does show, however, that a large part of job performance depends on factors other than general mental ability. Among those a candidate can work on concretely are:
- preparing on the role and the company, which translates into relevant questions;
- the ability to describe results and experience in an orderly, credible way;
- non-verbal communication: eye contact, posture, handling pauses;
- an image suited to the context, which conveys care without distracting.
Preparing for the interview beyond the score
A good aptitude test result often opens the door to the interview, but it rarely closes the selection on its own. It's worth preparing on both fronts: practising the tests and, at the same time, working on how to present yourself, tell your story and hold an important conversation.
If the latest estimate gives reasoning tests a correlation of 0.20 with performance, the rest of the game is played on what the recruiter sees and hears. That's where In-Job comes in, CG Imagine's programme for anyone facing an important job interview: image, communication and behaviour prepared methodically, so you arrive at the meeting feeling confident.
Photo by Vitaly Gariev on Unsplash
