Short answer: No IQ score for Alan Turing (1912–1954) is on record, and he was born too late for Catharine Cox's 1926 study of historical geniuses. Any number attached to him is a guess. The documented evidence is his work: a King's College fellowship at 22, the 1936 paper that defined computation, the wartime attack on naval Enigma and the 1950 paper that asked whether machines can think.
At a glance
| Estimated IQ | No scholarly estimate |
|---|---|
| Basis of estimate | None published; born in 1912, after the 1850 cutoff of Cox (1926) |
| Measured score | None on record |
| Born – died | June 23, 1912, Maida Vale, London – June 7, 1954, Wilmslow, Cheshire |
| Field | Mathematics, logic, computer science, cryptanalysis |
| Signature achievement | "On Computable Numbers" (1936); the imitation game, or Turing test (1950) |
| Comparable minds | John von Neumann, Kurt Gödel, Albert Einstein |
No test, no estimate
No intelligence-test result for Alan Turing appears in the documented record of his life. He never reported one, and none of the standard biographical sources cites one.
A retrospective estimate cannot fill the gap. Catharine Cox's 1926 study, the scholarly model for rating historical figures, covered only people born between 1450 and 1850. Turing was born in London on June 23, 1912. Our explainer on historical IQ estimates shows why that cutoff matters. Numbers that circulate online have no test and no named estimator behind them.
The boy his school worried about
Turing's schoolmasters saw the mind and disliked its direction. At Sherborne School his headmaster warned that "if he is to be solely a Scientific Specialist, he is wasting his time at a public school." By 1927 Turing was solving advanced problems without having been taught elementary calculus. At 16 he read Einstein's work on relativity and, his biographers suggest, inferred Einstein's challenge to Newton's laws of motion from a text that never stated it outright.
At King's College, Cambridge, he took a first-class degree in mathematics in 1934. The college elected him a Fellow in 1935, at 22, on the strength of work in probability theory that also won the Smith's Prize in 1936.
1936: defining what a computer is
In 1936 Turing submitted "On Computable Numbers, with an Application to the Entscheidungsproblem." The problem was David Hilbert's: could a mechanical procedure decide the provability of any statement in formal logic? To answer, Turing imagined a simple device that reads and writes symbols on a tape according to fixed rules. The answer was no. The device became the Turing machine, and the paper laid the foundation of the modern theory of computation and computability.
He then went to Princeton, where he completed a PhD under the logician Alonzo Church in 1938.
Bletchley Park
During the Second World War Turing led Hut 8 at Bletchley Park, the section attacking German naval Enigma, including the ciphers used by U-boats. He was central to the Turing–Welchman bombe, the electromechanical machine that from late 1940 made the reading of Luftwaffe signals routine.
He was appointed OBE in 1946 for his wartime service. Harry Hinsley, the official historian of British intelligence in the war, estimated that the Bletchley codebreaking effort shortened the war in Europe by more than two years.
Machines that think
Peace brought Turing to the machine his 1936 paper had imagined. At the National Physical Laboratory in 1945 and 1946 he designed the Automatic Computing Engine, or ACE. In October 1948 he moved to Manchester University as deputy director of its computing laboratory.
In 1950 the philosophy journal Mind published "Computing Machinery and Intelligence." It replaced the question of whether machines can think with a practical trial, the imitation game, now known as the Turing test. Turing predicted that within about fifty years an average interrogator would have no better than a 70 percent chance of identifying the machine after five minutes of questioning.
The Royal Society elected him a Fellow in 1951. His 1952 paper "The Chemical Basis of Morphogenesis" helped found mathematical biology. He was also a serious distance runner: his trial time for the 1948 Olympic marathon was only about 11 minutes slower than the silver medalist's 2 hours 35 minutes.
Turing beside Einstein, von Neumann and Gödel
Turing is often measured against Albert Einstein, the default symbol of genius. Alan Turing vs. Albert Einstein compares their records, and Einstein's IQ is as undocumented as Turing's.
The closer peer is John von Neumann, whose 1945 EDVAC report turned stored-program ideas into an engineering design; see Turing vs. von Neumann. Kurt Gödel's incompleteness theorems of 1931 set limits on formal proof, as Turing's 1936 paper set limits on computation; see Turing vs. Gödel. For the discipline as a whole, see mathematicians' IQs ranked.
What a score could not show
Even had Turing sat a modern test, the result would have been narrower than the man. A single IQ score carries a confidence interval of roughly five points either way, so a reported 150 means something close to 145 to 155. It would say nothing about originality, the quality that let him turn a question in logic into a model of computation still taught today.
His life ended in injustice. In 1952 he was convicted of gross indecency for a relationship with another man and accepted chemical castration instead of prison. He died of cyanide poisoning on June 7, 1954. The inquest recorded suicide, though the philosopher Jack Copeland has argued that accidental inhalation is equally plausible. In 2009 Prime Minister Gordon Brown issued a public apology, and in 2013 Turing received a royal pardon.
How we assessed this
We looked for a documented test result and found none, so we give no estimate. Biographical facts come from Andrew Hodges's entry on Turing for the Oxford Dictionary of National Biography, reproduced on his Turing website, and from standard reference sources. Quotations are verbatim from those sources.
Frequently asked questions
What was Alan Turing's IQ?
No one knows. No IQ test result for Turing is on record, and no psychologist has published an estimate; he was born in 1912, outside the 1450–1850 range of Catharine Cox's historical study. Online numbers are guesses. The documented evidence is his work, above all the 1936 paper that defined computation.
Was Alan Turing a genius?
On the evidence of his work, yes. He defined the theoretical computer in 1936, helped break German naval Enigma at Bletchley Park, designed the ACE stored-program computer and proposed the best-known test of machine intelligence. The Royal Society elected him a Fellow in 1951, when he was 39.
Who had a higher IQ, Alan Turing or Albert Einstein?
Neither has a verified IQ score, so the comparison cannot be made with numbers. Both changed how their fields define their basic objects: space and time for Einstein, calculation for Turing. For a side-by-side look at their records, see Alan Turing vs. Albert Einstein.
Did Alan Turing invent the Turing test?
Yes. He proposed it in 1950 in "Computing Machinery and Intelligence," published in the journal Mind, under the name "the imitation game." An interrogator questions a hidden human and a hidden machine through typed messages; if the interrogator cannot reliably tell them apart, the machine has done well. Turing expected machines to play the game convincingly within about fifty years.
Sources
- Andrew Hodges, "Alan Turing" (Oxford Dictionary of National Biography entry) — Education, fellowship, 1936 paper, Hut 8 and the bombe, ACE, Manchester, Mind paper, FRS, death
- Alan Turing – Wikipedia — Birth and death, headmaster's remark, early aptitude, Hinsley estimate, marathon, conviction, apology and pardon
- The Turing Test – Stanford Encyclopedia of Philosophy — Turing's 1950 prediction about the imitation game
- Cox, The Early Mental Traits of Three Hundred Geniuses (1926) – Internet Archive — Historical study limited to people born 1450–1850
Editorial standard: IQ figures for historical figures are retrospective estimates and are labeled as such; scores for living people appear only when the person disclosed them or a reputable outlet reported them. Corrections: contact the editors.
