IQ scores are considered one of the most accurate indicators of a person's intelligence. A score of 100 indicates a person with average intelligence. If someone scores above 140 on an IQ test, it means he or she can be considered a genius. But what's the limit and who had the highest IQ score ever? Keeping in mind that Albert Einstein – one of the most brilliant men in history – had a score between 160 and 190, take a look at these contenders for the highest IQs of all time:
William James Sidis
Sidis was born in 1898 in New York City, and though his IQ was never recorded (when he took an IQ test, his score was too high to measure), experts agree his score would have been astronomically high: between 250 and 300 to be exact. Sidis began reading newspapers at 1 1/2 years old. He learned several languages and made up his own by the age of 8. He enrolled in Harvard for mathematics at age 11, which at the time made him the youngest Harvard student ever. After a brief career as a teacher and a year in a sanatorium, Sidis lived a relatively normal life and died at age 46. While Sidis' IQ was never quantified, he's widely considered the smartest man ever.
Another child prodigy, Tao was born in Australia in 1975, and began solving math problems when he was 2 years old. His IQ score is estimated to be between 220 and 230. Tao's affinity for math took him through schooling quickly, and he graduated with both a bachelor's and a master's degree from Flinder's University at the age of 16. By 20, he'd earned a doctorate. Tao specializes in several complex math fields, including harmonic analysis and additive combinatorics, and he now teaches at the University of California, Los Angeles.
Hirata, a 31-year-old Japanese-American man has had a string of amazing accomplishments – which may be unsurprising when you consider his IQ is 225. Hirata's incredible intelligence led him to become the youngest American ever to win a gold medal at the International Physics Olympiad when he was just 13. At age 14 he began taking classes at the California Institute of Technology, and he started working on projects with NASA just two years later. After achieving a doctorate in astrophysics from Princeton at 22 years old, Hirata now teaches the subject at CIT.