Celebrities IQ

What Is William James Sidis's IQ?

By Samantha Davis, Psychology Writer
Published on August 09, 2024 | Updated on August 22, 2024

Image by The Sidis Archives, used under Public Domain / Incorporated into an illustration

William James Sidis Had an IQ of 275

William James Sidis, known for his extraordinary intelligence, had an IQ estimated at an astonishing 275. Born in 1898 in Boston, he was recognized as a child prodigy. By the age of 6, he had already mastered multiple languages including English, Latin, French, German, Russian, Hebrew, Turkish, and Armenian. He entered Harvard University at the age of 11, making headlines as one of the youngest students ever admitted. Despite his early fame, Sidis sought to live a private life, avoiding the public eye. After a short time as a mathematics professor, he moved from city to city, taking on various jobs under different names. He continued to write books, including a 1,200-page history of the United States and a work on streetcar transfer tickets. Most of his writings were published under pseudonyms. In 1937, the New Yorker published an article that portrayed Sidis as an eccentric failure, leading him to sue the magazine for invasion of privacy. He won the lawsuit, marking a significant moment in privacy law. Despite the negative media attention, those who knew him described him as a happy man in his later years. Sidis's life was marked by both extraordinary achievements and the challenges of living up to his early promise.

William James Sidis's IQ
275
profile picture of William James Sidis
How We Determined William James Sidis's IQ
High Confidence

Average Confidence Level

High

We relied on the findings of BBC Science Focus to estimate William James Sidis's IQ. We also reported the scores of three other sources for reference. Note that we used a midpoint approximation for this particular source.

BBC Science Focus
275 IQ High Confidence Confidence Level: High
NPR
275 IQ Medium Confidence Confidence Level: Medium
All That’s Interesting
275 IQ Medium Confidence Confidence Level: Medium
Science ABC
275 IQ Low Confidence Confidence Level: Low

5 Facts That Show How Smart William James Sidis Was

  • Early Reading Skills: By 18 months, William James Sidis could read The New York Times. This extraordinary feat showcased his ability to comprehend and interact with text at an incredibly young age.
  • Youngest Harvard Student: Sidis was admitted to Harvard at age 11, setting a record as the youngest person to enroll at this prestigious institution. He even gave a presentation on four-dimensional bodies the year of his admission. This demonstrated his exceptional intellectual capabilities.
  • Polyglot Abilities: He mastered over 40 languages and dialects, a testament to his incredible linguistic intelligence and his voracious appetite for learning.
  • Advanced Mathematics: At age 8, Sidis developed his own original language and. By the age of 10, he was already giving lectures in higher mathematics, illustrating his profound grasp of complex mathematical concepts.
  • Vast Intellectual Output: Sidis wrote numerous books and essays on subjects ranging from cosmology to history, often under pseudonyms, reflecting his wide-ranging knowledge and prolific output.
Image by The Sidis Archives, used under Public Domain / Incorporated into an illustration
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How Does William Sidis's IQ Compare to the Rest of the World?

William Sidis ranks far beyond the ordinary with an IQ of 275, even when compared to members of high-IQ societies. This level of intelligence is extraordinarily rare. To put this into perspective, most people can't even qualify for Mensa, which requires a score of 130 for most standardized IQ tests – or 132 for the Stanford Binet 4th Edition.

Image by The Sidis Archives, used under Public Domain / Incorporated into an illustration

How William Sidis's IQ Stacks Up Against Other Public Figures

Here's the revised version with the links in plain HTML text: As one of the people with the highest IQs in the world, William Sidis truly stands out with an IQ of 275. Right behind him, Marilyn vos Savant, known for her famous column in Parade magazine, shines with an IQ of 228, blending her incredible intelligence with public engagement.

Christopher Langan, often called "the smartest man in America," has an IQ score of 200. Fun fact: he worked as a bouncer for 20 years!

Ken Jennings, with his 173 IQ, turned trivia knowledge into stardom on "Jeopardy!" His success shows that knowing a lot of random facts can actually pay off.

In a different shift, Kim Kardashian's IQ of 165 has helped her transition from entertainment to law. While she hasn't made a complete transition to law, she is seriously pursuing it as a significant part of her career. She’s proving that reality TV stars can have serious brains too.

Lastly, Cindy Crawford's 154 IQ breaks stereotypes, merging academic ability with supermodel status. She shows that beauty and brains can go hand in hand.

Illustration composed of multiple sources: images by The Sidis Archives under Public Domain, rellymath under CC BY-SA 2.0, rellymath under CC BY-SA 2.0, pasquinade under CC BY-NC-ND 2.0, Eva Rinaldi Celebrity Photographer under CC BY-SA 2.0, Ibsan73 under CC BY-SA 2.0 / Incorporated into an illustration

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