What Was Charlie Munger's IQ? What the Record Shows About Berkshire's Architect

Charlie Munger's IQ is unknown: no IQ test result for him has ever been published, and he never claimed a number. The figures that circulate online, including a "149" said to come from a wartime Army test, have no traceable source, so any Charlie Munger IQ figure is a guess built backward from his career. Munger died on November 28, 2023, 33 days before his 100th birthday, after more than four decades as vice chairman of Berkshire Hathaway. This article covers what the documented record shows, what Munger himself said about intelligence, and what an investing career can and cannot tell us about a test score.

No. Berkshire Hathaway's announcement of his death, Warren Buffett's tribute in his 2023 shareholder letter, and the major obituaries describe his education and career without mentioning any intelligence test. Munger gave interviews and annual-meeting answers for decades, and no score from any of them has surfaced.

The most specific number online is a claim on a personal-finance blog that Munger "scored 149" on the Army's classification test during World War II. The post cites no source and does not say what scale the number was on. The Army General Classification Test was a group screening test used to sort Army recruits into military jobs, as industrial psychologist Thomas Harrell's history of the test describes. Even a genuine wartime classification score would not be an IQ from a modern, individually normed test, so the 149 should be treated as unverified.

The same pattern runs through celebrity IQ claims generally. Our article on Warren Buffett's IQ traces his partner's "150" to the same kind of dead end.

Munger's record is unusual, and most of it is easy to verify.

• Michigan and the Army Air Corps: Born in Omaha on January 1, 1924, Munger was a student at the University of Michigan when he enlisted in the U.S. Army Air Corps after Pearl Harbor, according to Caltech's alumni association.

• Meteorology at Caltech: In the fall of 1943 the Army sent him to Caltech for special meteorology courses for Army Air Force cadets, because his wartime job would be forecasting flight conditions. He completed the program with a meteorology certificate.

• Harvard Law without a bachelor's degree: CNN's biographical file notes that Munger entered law school without an undergraduate degree and graduated magna cum laude from Harvard Law School in 1948.

• Berkshire's vice chairman: He became vice chairman of Berkshire Hathaway in 1978 and was chairman and chief executive of Wesco Financial from 1984 to 2011, as CNBC's obituary reports.

• The "architect": In his 2023 shareholder letter, published in February 2024, Buffett credits Munger's 1965 advice to buy "wonderful businesses purchased at fair prices" instead of fair businesses at wonderful prices, and calls him "the 'architect' of the present Berkshire."

Taken together, the record shows a person who handled demanding technical and legal training at an elite level, then spent decades making high-stakes judgments in public. That is real evidence of high ability. It is still not a measurement.

Munger talked about thinking constantly, and his best-known lines put brains in a supporting role.

His most quoted remark on the subject comes from a letter to Wesco Financial shareholders dated March 5, 1990, printed in Wesco's 1989 annual report: "It is remarkable how much long-term advantage people like us have gotten by trying to be consistently not stupid, instead of trying to be very intelligent." Quote Investigator traced the sentence to that letter, which settles both its wording and its date.

In his 2007 commencement address at the USC Gould School of Law, Munger said: "I constantly see people rise in life who are not the smartest, sometimes not even the most diligent, but they are learning machines." He gave the same explanation for Berkshire, saying its record would have been impossible without Buffett being "a continuous learning machine."

In an April 1994 talk to students at USC's Marshall School of Business, Munger argued that good judgment comes from the key ideas of many disciplines held together, which he called a "latticework" of models. Investment writer Robert Hagstrom, who built a book around the talk, quotes his core instruction: "You've got to have models in your head." Hagstrom notes that "latticework" became a shorthand term in the investment world for Munger's approach.

None of this is Munger denying that intelligence matters. His point was that once a person is capable enough, the habits of avoiding obvious errors and continuing to learn decide more of the outcome. He never put a number on "capable enough," and his record cannot settle it for him.

There is good evidence that intelligence matters in investing. In a study of Finnish men whose IQ was measured at military induction, Mark Grinblatt and colleagues found that stock market participation rose steadily with IQ, even after controlling for wealth and income, and that higher-IQ investors were more likely to hold mutual funds and more individual stocks, took less risk and earned higher risk-adjusted returns. More broadly, a meta-analysis of longitudinal studies by Tarmo Strenze found that measured intelligence predicts later education, occupational status and income, with the strongest links for education and the weakest for income.

Those findings run forward, from a test score to later outcomes. Estimating Munger's IQ requires running them backward, from one extraordinary career to a score, and that is where the method breaks. Many people with very high scores never build anything like Berkshire, and an outcome as rare as Munger's depends on timing, partnership, temperament and decades of compounding as well as ability. A researcher can say the record makes a high score likely. Nobody can say which score. The same limit applies to the mathematician Jim Simons, whose firm, Renaissance Technologies, the Simons Foundation describes as one of the most profitable investment firms in history: a record like that narrows the range of plausible scores without producing one.

That is also why labels from his obituaries, "investing genius" among them, tell us about reputation and nothing about a number. Our guide to what counts as a genius IQ score explains why even the threshold is a convention. And for the general research on ability and outcomes, see our article on whether high IQ correlates with success.

Nobody knows. No IQ test result for Munger has ever been published, and he never stated a score, so every number attached to him is an estimate.

That claim appears on a personal-finance blog with no source. None of the obituaries or Berkshire documents gives a test number, and a wartime Army classification score would not be a modern IQ score in any case.

He studied at the University of Michigan and took Army meteorology courses at Caltech during World War II, but did not finish a bachelor's degree. He was admitted to Harvard Law School anyway and graduated magna cum laude in 1948.

His best-known line, from a 1990 letter to Wesco shareholders, is that "people like us" gained a long-term advantage "by trying to be consistently not stupid, instead of trying to be very intelligent." In 2007 he added that the people he saw rise were often not the smartest but were "learning machines."

In a 1994 talk at USC's business school, Munger described good judgment as a "latticework" of the key ideas from many fields, used together. "Latticework" has since become investment-world shorthand for his approach.

There is no Charlie Munger IQ score, and the 149 that turns up online has no source behind it. What does exist is a well-documented life, from Harvard Law without a bachelor's degree to decades as the partner Buffett calls Berkshire's architect, along with Munger's own view that steady learning and avoiding stupidity beat raw brilliance. If you want a number that comes from measurement rather than inference, take a full-length online IQ test with published norms and a stated margin of error.

1. Berkshire Hathaway Inc. (2023, November 28). News release [Death of Charlie Munger]. [berkshirehathaway.com](. berkshirehathaway.com

2. Buffett, W. E. (2024, February 24). 2023 shareholder letter [Charlie Munger: The architect of Berkshire Hathaway]. Berkshire Hathaway Inc. [berkshirehathaway.com](. berkshirehathaway.com

3. Caltech Alumni Association. (2023, November 28). Charles T. Munger. California Institute of Technology. [alumni.caltech.edu](. alumni.caltech.edu

4. CNN Editorial Research. (2014, June 11; updated). Charlie Munger fast facts. CNN. [cnn.com](. edition.cnn.com

5. Steinberg, M. (2023, November 28). Charlie Munger, investing genius and Warren Buffett's right-hand man, dies at 99. CNBC, via NBC News. [nbcnews.com](. nbcnews.com

6. Harrell, T. W. (1992). Some history of the Army General Classification Test. Journal of Applied Psychology, 77(6), 875-878. [doi.org/10.1037/0021-9010.77.6.875](. doi.org

7. O'Toole, G. (2025, August 25). Trying to be consistently not stupid instead of trying to be very intelligent. Quote Investigator. [quoteinvestigator.com](. quoteinvestigator.com

8. Munger, C. T. (2007, May 13). USC Law School commencement address [Transcript]. Reprinted by James Clear. [jamesclear.com](. jamesclear.com

9. Hagstrom, R. G. (2013). Investing: The last liberal art (2nd ed.). Columbia University Press. [doi.org/10.7312/hags16010](. doi.org

10. Grinblatt, M., Keloharju, M., & Linnainmaa, J. (2011). IQ and stock market participation. The Journal of Finance, 66(6), 2121-2164. [doi.org/10.1111/j.1540-6261.2011.01701.x](. doi.org

11. Strenze, T. (2007). Intelligence and socioeconomic success: A meta-analytic review of longitudinal research. Intelligence, 35(5), 401-426. [doi.org/10.1016/j.intell.2006.09.004](. doi.org

12. Sumner, T. (2024, May 10). Simons Foundation co-founder, mathematician and investor Jim Simons dies at 86. Simons Foundation. [simonsfoundation.org](. simonsfoundation.org

Hero image: Charlie Munger, photo by Nick, CC BY 2.0. Via Wikimedia Commons.