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

Richard Feynman vs William James Sidis

Richard Feynman (IQ —) vs William James Sidis (IQ 250). Side-by-side comparison of intellect, achievements, era and cultural impact.

Richard Feynman
1918–1988 · US
Estimated IQ
Read full biography →
William James Sidis
1898–1944 · US
250
Estimated IQ
Read full biography →
Born19181898
Died19881944
CountryUSUS
Estimated IQ 250
Best known forManhattan Project AcousticThe Animate And The Inanimate

Who had the higher IQ?

Reliable IQ figures aren't available for both. The richer comparison is what each accomplished and how it changed their field.

Achievements compared

Richard Feynman is best known for: Manhattan Project Acoustic William James Sidis is best known for: The Animate And The Inanimate

Recognition. Richard Feynman: Albert Einstein Award (1954) • E. O. Lawrence Award (1962) • Nobel Prize in Physics (1965) • Foreign Member of the Royal Society (1965) • Oersted Medal (1972) • National Medal of Science (1979). William James Sidis: —.

Different eras, different boards

The two were born roughly 20 years apart (1918 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, Richard Feynman or William James Sidis?
Estimated IQs are — for Richard Feynman and 250 for William James Sidis. William James Sidis rates higher by 250 points. Historical IQ figures are reconstructions, not measured scores.
What is Richard Feynman most famous for?
Manhattan Project Acoustic
What is William James Sidis most famous for?
The Animate And The Inanimate
Did Richard Feynman 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 artist cut off part of his own ear?
🧠 Which Genius Are You?📊 Free IQ Test