Does IQ predict job performance?

Cognitive ability predicts job performance across virtually all occupations, with operational validities (Hunter & Schmidt meta-analyses) of approximately 0.5 for complex jobs and 0.2 for simple jobs. This makes IQ one of the strongest single predictors of job performance available to employers, comparable to structured interviews and substantially stronger than unstructured interviews, education credentials, or experience. The correlation is partly mediated by job-specific learning: cognitively able workers acquire job-relevant knowledge faster, which then translates into better performance. Cognitive testing for employment purposes is legal but heavily regulated in many jurisdictions, requiring documented job-relatedness and validation studies.

This question comes up frequently from users of free online IQ tests and from people considering whether to pursue a clinical evaluation. The full answer depends on context — what the score will be used for, how recently the test was administered, and what other information is available. The brief answer above captures the broad consensus from the published research literature; the linked deep-dive articles cover the underlying evidence in more detail.

Related considerations include the standard error of measurement on the relevant test, the population the test was normed against, and the specific cognitive abilities the test samples. A score is much more informative when interpreted alongside these contextual variables than when reported as a bare number.

If this answer raises further questions, see the related FAQ entries listed in the sidebar and the longer-form articles on the same topic in the article library. The site is designed to provide layered depth: the FAQ entries offer concise answers, the deep-dive articles offer the underlying research, and the score-interpretation pages tie the abstract concepts to specific result bands.