The absolute score of an IQ test is less significant than an individual’s ranking within the tested group, and its predictive power depends on the context of the test.

IQ tests measure performance relative to a specific cohort, not an absolute measure of intelligence. Their results are meaningful only within the context of the group and the test’s design. For example, a test administered in Dutch might assess language fluency and problem-solving skills relevant to daily life in a Dutch-speaking society. If someone like Mohamed, who is not fluent in Dutch, takes this test, his score may reflect his language limitations rather than his overall cognitive ability. However, the same test could still predict his potential productivity in a Dutch-speaking environment, as it measures skills relevant to that context.

IQ remains the strongest single predictor of economic success across contexts, as it correlates with skills like problem-solving and adaptability that contribute to earning potential.

Comparing scores across cultures is challenging.