What was Carl Jung’s IQ?
He timed answers to 100 stimulus words with a stopwatch, and the Myers-Briggs types grew out of his 1921 book, yet neither is an IQ test and Jung left no IQ score.

Carl Jung’s IQ is quoted as 165, and neither page that prints it cites a test. The Genius Index lists an “Estimated Cognitive Quotient” of 165; its methodology page lists clinical scores, SAT and GRE conversions and, for historical figures, Catharine Cox’s historiometric methods, and the Jung page does not say which produced the number. geniuses.club lists an estimated IQ of 165 and adds that such figures are published estimates, not a measured, verified test score. On Reddit the number passes from person to person, in comments that give 160, 165 or 175 and, in an August 2022 r/Jung thread, “What do you think Jung’s IQ was?”, guesses from 115 to about 170. None cites a test, which is the usual pattern for a celebrity IQ number.

No Carl Jung IQ score could have come from a test taken in his student years: the Binet–Simon intelligence scale appeared only in 1905, the year Jung qualified as a university lecturer; the abbreviation IQ comes from William Stern’s 1912 book and the Stanford revision of Binet’s scale from 1916 (see the history of intelligence testing). Jung’s own instrument was of another kind. M. D. Eder’s preface to the 1919 English edition of Studies in Word-Association dates the experimental study of mental association to Galton’s work in 1879 and Wundt’s in 1880, says Jung’s new departure was applying the method to unconscious processes, and hopes for standard tests for normal and abnormal children complementary to Binet’s intellectual tests. Jung and Franz Riklin timed the answers of 38 people, educated and ill-educated, with a stopwatch that read to a fifth of a second, and reported that a lack of intelligence was “far less disturbing than affect.” The method was built to expose emotionally charged complexes, not to rank ability.

A search for a “Carl Jung IQ test” can land on personality quizzes, which are not IQ tests either. Jung’s 1921 Psychological Types sorted people by two attitudes, introversion and extraversion, and four functions: thinking, feeling, sensation and intuition. It reached English in 1923; Katharine Cook Briggs had already begun her own personality system, and her daughter Isabel Briggs Myers built the Myers-Briggs Type Indicator on Jung’s theory. The Myers & Briggs Foundation says the assessment “sorts for preferences; it does not measure traits, ability, skill, or character.” A thinking type is therefore not a cleverer type, and no type result is an IQ, a difference set out under IQ versus personality.

A Carl Jung IQ level of 165 is not a number a test would readily return either. On the scale modern tests use, with a mean of 100 and a standard deviation of 15, it is 4.3 standard deviations above average, about one person in 136,000; at that height test ceilings thin out the items and the norming sample, and Wikipedia’s article on the intelligence quotient says reports of scores much higher than 160 are considered dubious. Cox’s 1926 study of 301 geniuses does not fill the gap: its subjects lived between 1450 and 1850, and Jung was born in 1875. The record supports a wider, lower band. Carl Jung’s estimated IQ of 140–160 has a bottom edge, an IQ around 140, of about one person in 260 and a top edge, an IQ of 160, of about one in 31,600. Among this site’s science profiles, that band sits above Jordan Peterson (125–140), whose Maps of Meaning (Routledge, 1999) its publisher describes as combining Freudian and Jungian approaches to mythology and narrative; it overlaps Noam Chomsky (150–170), who stands 38th in the same eminence table; and it stops short of Albert Einstein (160–180), whom Jung recalled in a 1953 letter as a dinner guest who first set him thinking about the relativity of time. All four ranges rest on records, not scores.