William James Sidis

William James Sidis (/ˈsaɪ dɪs/; April 1, 1898 – July 17, 1944) was an American child prodigy with exceptional mathematical and linguistic abilities. During his life, his ratio IQ was estimated to be between 250 and 300, making it one of the highest ever recorded but the testing was different from standard IQ tests. He entered Harvard at age 11 and, as an adult, was claimed to be conversant in over forty languages and dialects. It was later acknowledged, however, that some of the claims made were exaggerations, with a researcher stating "I have been researching the veracity of primary sources of various subjects for about twenty-eight years, and never before have I found a topic so satiated with lies, myths, half-truths, exaggerations, and other forms of misinformation as is in the history behind William Sidis". Sidis became famous first for his precocity and later for his eccentricity and withdrawal from public life. Eventually, he avoided mathematics altogether, writing on other subjects under a number of pseudonyms.