Harold Marshall Finley was born on February 24, 1916 in McConnelsville, Morgan County, Ohio, United States. He was a son of Harry Marshall Finley, a lawyer, and Kate Finley. At nine months, Finley walked 30 feet across the floor. By 2, he taught himself to read and, 10 months later, could tell time even with his pocket watch upside down. Finley wrote a 100-page book at age 5, the same year he took a Stanford-Binet intelligence quotient test administered by Ohio State University students. When his 168 score was challenged, he took it again and earned 197 on another test, the second highest IQ ever recorded in the country at that time.