Free PDF: The Genius Workout — 50 brain teasers + the 25 highest IQs in history.
Head-to-Head Comparison

Paul Dirac vs William James Sidis

Paul Dirac (IQ 190) vs William James Sidis (IQ 250). Side-by-side comparison of intellect, achievements, era and cultural impact.

Paul Dirac
1902–1984 · ENG
190
Estimated IQ
Read full biography →
William James Sidis
1898–1944 · US
250
Estimated IQ
Read full biography →
Born19021898
Died19841944
CountryENGUS
Estimated IQ 190 250
Best known forSharing the 1933 Nobel Prize in Physics with Erwin Schrödinger "for the discovery of new productive forms of atomic theory"The Animate And The Inanimate

Who had the higher IQ?

By the most cited estimates, William James Sidis tops this matchup with an estimated IQ of 250, a 60-point margin over Paul Dirac (190). IQ estimates for historical figures are reconstructions, not test results — they sit on top of biographical evidence, productivity, and the difficulty of the problems each person solved. Treat the number as a directional signal, not a verdict.

Achievements compared

Paul Dirac is best known for: Sharing the 1933 Nobel Prize in Physics with Erwin Schrödinger "for the discovery of new productive forms of atomic theory" William James Sidis is best known for: The Animate And The Inanimate

Recognition. Paul Dirac: Nobel Prize in Physics (1933) • Royal Medal (1939) • Copley Medal (1952) • Max Planck Medal (1952) • Fellow of the Royal Society (1930). William James Sidis: —.

Different eras, different boards

The two were born roughly 4 years apart (1902 vs 1898), which matters: scientific tools, available knowledge, and intellectual culture compound. Comparing minds across eras is comparing players on different boards.

The verdict

So who was greater? The honest answer: they're not strictly comparable. By raw IQ proxy, William James Sidis edges out. By measurable, lasting influence in their respective field, both are anchors of the human record. If you have to pick one to bet civilization on, pick the one working on the problem you care about.

Frequently Asked

Who had the higher IQ, Paul Dirac or William James Sidis?
Estimated IQs are 190 for Paul Dirac and 250 for William James Sidis. William James Sidis rates higher by 60 points. Historical IQ figures are reconstructions, not measured scores.
What is Paul Dirac most famous for?
Sharing the 1933 Nobel Prize in Physics with Erwin Schrödinger "for the discovery of new productive forms of atomic theory"
What is William James Sidis most famous for?
The Animate And The Inanimate
Did Paul Dirac and William James Sidis ever meet?
They were contemporaries, though there is no documented direct meeting in our sources.

Related Comparisons

Explore more genius comparisons

See the IQ Rankings →
ENEspañolFrançaisDeutschPortuguês日本語Italiano中文한국어العربيةहिन्दीРусскийTürkçe

Play & come back tomorrow

🔥 Daily Genius Challenge · Genius trivia
Which mathematician proved that no consistent system can prove all truths (incompleteness)?
🧠 Which Genius Are You?📊 Free IQ Test