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Atlas/Presidents/Abraham Lincoln
Official measure

Abraham Lincoln’s IQ

Abraham Lincoln served as the 16th president of the United States (1861–1865). Simonton 2006 Table 1 column II-C (2C) estimates 150; that is a historiometric model, not an administered IQ test.

Direct answer150

Simonton 2006 2C estimate: 150. Historiometric model, not a measured IQ score.

See 150 on the IQ scale
1809–1865
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
150estimated IQ points

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

Table 1 column II-C is 150 (displayed as 150). 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: 150. 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.

Full evidence investigations
Evidence trail

Why this page exists

Abraham Lincoln is a high-demand presidential IQ search. The first useful answer is the published 2C integer (150), then the method that produced it, then what it is not.

  1. Three integers from one column. Jefferson 160, Lincoln 150, Kennedy 160. Kennedy’s unpublished-in-the-headline decimal is 159.8.
  2. Same method, still not a test. All three numbers come from the same historiometric pipeline. That makes them more comparable to each other than to a viral internet score—and still not WAIS results.

Conclusion. On Simonton 2006 II-C, Jefferson is 160, Lincoln is 150, and Kennedy is 159.8 (displayed 160). The gap is a model difference, not a documented test difference.

Where 150 sits on the IQ scale

This is the same mean-100, SD-15 model used on the homepage. It explains the integer. It does not turn 2C into a WAIS result.

Explore IQ 150 on the interactive bell curve · Presidents sorted highest to lowest.

Questions this page answers

What was Lincoln's IQ?
This atlas displays 150 from Simonton 2006 Table 1 column II-C (2C). It is a historiometric estimate, not an administered IQ test.
Is that a real IQ test?
No. Simonton reconstructed estimates from biographical ratings and earlier Cox-style figures. There is no public WAIS or Stanford–Binet protocol for this number.
Why show one number instead of a range?
The paper publishes four variants. IQ Caddy ranks and displays II-C so the list can be sorted highest to lowest, with the Estimate badge attached.

Related investigation: Jefferson vs Lincoln vs Kennedy: three Simonton 2C numbers.