What methodology do fact-checkers use to verify claimed IQ scores?

1. What “IQ” actually measures — the baseline journalists use

Fact‑checkers start from the scientific definition: modern IQ tests produce a score that locates an individual relative to a reference population (mean ≈100, SD ≈15) rather than measuring an absolute quantity; older definitions used mental‑age ratios, but contemporary practice is norm‑referenced scaling ^[1]. Analysts also note that IQ scores estimate some cognitive abilities (a “g” factor in composite scores) but are affected by social, health and environmental factors, so scores must be interpreted within context rather than as immutable personal labels ^{[5] [2]}.

2. Documenting the provenance of a claimed score

The first verification step is documentary: which test was claimed (WAIS, WISC, Stanford–Binet, Raven’s matrices, a platform test, etc.), date of administration, administering professional, and whether a score report or certificate exists. Many public IQ figures come from online or platform tests—these provide instant estimates but are not equivalent to clinician‑administered standardized instruments; fact‑checkers flag unspecified or platform‑only tests as weaker evidence ^{[3] [6] [4]}.

3. Distinguishing standardized, normed tests from online quizzes

Professional instruments are age‑normed and psychometrically validated; they produce scores with known error and confidence intervals. By contrast, many commercial or free online tests give quick estimates and sometimes claim to normalize to mean 100, SD 15, but their samples and calibration differ. Fact‑checkers therefore treat online results as provisional unless the test’s validity and sampling methods are documented ^{[3] [4] [6]}.

4. Checking psychometrics: norms, standardization, and error margins

A core verification is whether the test uses established norms and reports measurement uncertainty (confidence intervals). Good practice in reporting IQ includes the test name, normative sample, and an acknowledgement of error—some analysts recommend giving scores ± a few points because of measurement error and practice effects ^{[2] [5]}. Fact‑checkers quote these intervals where available and treat single‑point claims without uncertainty skeptically ^[2].

5. Looking for independent corroboration

When a public figure cites a high or low IQ, fact‑checkers look for corroborating evidence: a sealed or published score report, statements from the administering psychologist, or contemporaneous documentation. If the claim rests on aggregated country or group estimates (e.g., average IQ by country), reporters check methodology: whether averages derive from standardized national testing, meta‑analysis, or platform participant data—and note that methods and data quality shape the result ^{[7] [4] [8]}.

6. Evaluating population‑level claims vs. individual claims

Country or state averages are composite estimates built from various tests and adjustments—sites that publish national rankings often combine standard IQ tests with academic achievement metrics and data‑quality weighting. Fact‑checkers scrutinize these methodological decisions because they strongly influence rankings and margins of uncertainty ^{[7] [9] [8]}. Individual score claims require different standards: authenticated test reports and qualified administration ^{[3] [6]}.

7. Exposing common weaknesses and misleading practices

Reporters call out common red flags: unnamed tests, screenshots without provenance, self‑reported online quiz screenshots, and claims that ignore confidence intervals or the test’s cultural bias and socioeconomic confounds. Sources caution that IQ is influenced by education, nutrition and health—factors that complicate simple interpretations of group differences and can be exploited by actors pushing political or cultural agendas ^{[5] [2]}.

8. How fact‑checkers present uncertainty to readers

Because IQ is relative, subject to measurement error, and sensitive to methodology, credible fact checks present the instrument used, the certifying professional (if any), the normative basis (mean/SD), and any stated confidence interval; they note when sources do not mention key details (e.g., “available sources do not mention test administration by a licensed psychologist”) and avoid treating point estimates as definitive ^{[1] [2]}.

9. Competing perspectives and why they matter

Some organizations publish large international rankings using platform data or mixed sources and defend their methods (normalization, Raven’s matrices, combining PISA/TIMSS); others criticize such rankings for sampling bias or methodological heterogeneity. Fact‑checkers therefore present both the ranking claim and critiques about comparability and data quality so readers see the disagreement rather than a single authoritative number ^{[4] [8] [7]}.

10. Practical checklist for readers and reporters

To vet a claimed IQ: ask which test and edition, who administered it, request a dated score report, look for normative data and confidence intervals, and assess whether the claim rests on an online platform or a validated clinical instrument. If those elements are missing, treat the claim as unverified—available sources do not mention independent validation in many platform‑based reports ^{[3] [4]}.

Limitations: This summary draws on materials about IQ measurement, online testing, and country‑level aggregation methods in the provided reporting; specific fact‑checking protocols used by individual outlets are not detailed in these sources—available sources do not mention a single standardized checklist used across all fact‑checkers.