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Atlas/Presidents/William McKinley
Official measure

William McKinley

William McKinley served as the 25th president of the United States (1897–1901). Simonton 2006 Table 1 column II-C (2C) estimates 143; that is a historiometric model, not an administered IQ test.

Direct answer143

Simonton 2006 2C estimate: 143. Historiometric model, not a measured IQ score.

See 143 on the IQ scale
1843–1901
Evidence ledger

What the record supports

Every card keeps the measure, year, method, and limitations attached to the number—or explains why no number is shown.

Historical estimate2006
143estimated IQ points

Simonton 2006 Table 1 II-C (2C) estimate

Table 1 column II-C is 143.4 (displayed as 143). II-C is the ages 18–26 estimate corrected for data reliability. Simonton also reports I-U, I-C, and II-U; those other variants are lower or equal. 2C is still a model, not a test.

Simonton 2006 2C estimate: 143. Historiometric model, not a measured IQ score.
Method and limits

Simonton used expectation-maximization with prior biographical ratings of intellectual brilliance, openness, and the limited Cox retrospective estimates. This atlas ranks and displays column II-C.

  • No administered IQ test underlies this record.
  • The models depend on historical biographical ratings and assumptions about missing values.
  • Displaying 2C as one number is a ranking convention, not proof of a test result.
  • II-C is the most generous of the four variants; the lower variants would produce a lower or equal estimate.

Uncertainty: 2C is one of four published model variants, not a confidence interval or an administered test score.