Composers Ranked by Estimated IQ: What the Evidence Supports

The ranking

The table below lists every composer whose Cox figures we could confirm in the 1926 text, with the two estimates she published for each: one from the record to age 17, one from the record between 17 and 26. It also lists major composers who were never rated. Where no scholarly figure exists, we say so.

Three more composers appear in Cox's sample: Giovanni Pierluigi da Palestrina, the 16th-century master her case file calls "Princeps Musicae," Carl Maria von Weber and Gioachino Rossini. Their case studies sit in the chapters for childhood ratings of 110 to 120, 130 to 140 and 120 to 130 respectively, below Mozart and Mendelssohn.

Where every number comes from

Cox, a doctoral student of Lewis Terman at Stanford, published The Early Mental Traits of Three Hundred Geniuses in 1926 as the second volume of Terman's Genetic Studies of Genius. She began with James McKeen Cattell's 1903 ranking of the most eminent people in history, kept those born between 1450 and 1850, and ended with 301 subjects. Composers were a small group within it.

Terman, the psychologist Maud Merrill and Cox rated every subject. They read biographies, letters and school records and asked what mental age each documented feat implied. The result is a ratio IQ, "the ratio of mental age to chronological age," expressed on the childhood norms of the 1920s. Cox also graded the reliability of each record, from near zero to about .8, and published those grades beside the estimates.

Why music confused the raters

Composers were among Cox's hardest cases, and she said so. For the young Mozart, Terman gave 125, Merrill 190 and Cox 140, a spread she attributed to "the difficulty of estimating the intelligence of a musical prodigy." Her notes found his reading and letters unremarkable; his precocity showed almost entirely in music.

Bach produced a similar split. "In the case of Bach the disagreement among the raters resulted from the problem of weighting musical achievement," Cox wrote, adding that "the correlation between musical achievement and intelligence is unknown." She settled on 125 as "a safe rating." Mendelssohn was the easy case: he "early showed high general ability as well as phenomenal musical talent," so both kinds of evidence pointed the same way.

The lesson carries into any ranking of musical geniuses. A composer with a broad paper trail of schooling and letters scores higher than one whose gift left evidence only in scores, whatever their musical rank.

Why so many lists say 165

Popular IQ lists give Mozart, Beethoven and Bach the same figure: 165. That is not a contradiction of the table above. The 165 is Cox's reliability-corrected figure for each man, copied from secondary tabulations of her 1926 data.

Cox noticed that her estimates rose with the quality of the evidence, which meant thin records understated ability. She therefore computed "an approximation to the IQ that would have been obtained if the data had all been equally and sufficiently reliable." The corrections are large where records are weak. Bach and Beethoven climb 25 points from 140; Mozart, on better evidence, climbs 10. The same secondary tables list Handel and Wagner at 170 and Haydn at 160.

Cox applied the same logic to her whole sample, concluding that its true mean was "not below 155 and probably at least as high as 165." Use the obtained figures in our table when you want her raters' actual judgments; treat the corrected ones as a statistical projection.

Intelligence was not the deciding factor

The psychologist Dean Keith Simonton, reviewing Cox's composers in The Psychologist in 2009, calculated that estimated IQ and eminence correlated at .54 across all 11. That is a real relationship, strong for social science, and far from destiny. Gluck, with the lowest estimate at 110 to 115, still made Cox's list of the most eminent people of four centuries.

Cox's own conclusion pointed to character. High but not the highest intelligence, joined to the greatest persistence, would outrank the highest intelligence with less drive. Simonton noted that exceptional composers showed traits such as "desire to excel," "belief in their own powers" and "persistence in the face of obstacles." His verdict on the most famous comparison: Beethoven may not have had Mozart's intelligence, "but he had more than enough persistence to compensate."

The composers Cox never rated

The ranking has large holes. Frédéric Chopin and Franz Schubert, both born inside Cox's window, do not appear in her book at all. Every composer born after 1850, from Stravinsky onward, falls outside it. For them no scholarly IQ estimate exists, and any number on a quiz site or listicle is unsourced.

The same holds for composers of film music. Charlie Chaplin left school by 13, scored most of his own films and won the 1973 Oscar for Best Original Dramatic Score for Limelight, shared with collaborators Raymond Rasch and Larry Russell. He was never tested and never estimated. His place in this table is a reminder that musical achievement and a documented IQ are different things.

Composers beside scientists and artists

Cox's scale lets composers be set against other fields, with the same caveats. Mozart's 150 and 155 sit near Michelangelo's 145 and 160 and above Leonardo da Vinci's 135 and 150. Isaac Newton shows how much the two age bands can differ: 130 for childhood, 170 for ages 17 to 26.

Artists and composers share a disadvantage in Cox's method. Michelangelo's raters split 130, 160 and 140 for the same reason Mozart's did, and Cox called his case another example of the difficulty of rating artistic production. For the full cross-field list, see genius IQ scores, complete list.

How to read these numbers

Three rules keep the table honest. First, these are estimates from documents, not test scores; a modern test report would attach a margin of error of roughly five points to far better data. Second, they are ratio IQs on 1920s childhood norms, not deviation scores from today's Wechsler or Stanford-Binet 5 tests, so converting them to percentiles is at best approximate. Third, differences of five or ten points between composers fall inside the disagreement among Cox's own raters.

For what the numbers would mean on a modern scale, see IQ 155 and IQ 140. For the method's limits, read historical IQ estimates explained. For what research says about music and cognitive ability, see music and intelligence, and for the composers ranked by achievement rather than IQ, the greatest composers.

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.