William James SidisWikimedia CommonsWilliam James Sidis in 1914. He’s about 16 years old in this photo. In 1898, the smartest man who ever lived was born in America. His name was William James Sidis and his IQ was eventually estimated to be between 250 and 300 (with 100 being the norm).
Marilyn vos SavantThe person with the highest IQ score in the world is American magazine columnist Marilyn vos Savant, 74, according to the Guinness Book of Records. She has an IQ of 228.
160The maximum IQ score assigned by the WAIS-IV, a commonly-used test today, is 160. A score of 135 or above puts a person in the 99th percentile of the population. News articles often put Einstein’s IQ at 160, though it’s unclear what that estimate is based upon.