Alfred Kinsey was the 20th century's first and most influential researcher into sex. His Sexual Behaviour of the Human Male (The Kinsey Report on Sex), published in 1948, was an explosive bestseller, followed in 1953 by his even more controversial statistics on female sexuality. Both studies were based on thousands of interviews and case histories. This biography describes his strict Methodist upbringing, his love of minute observation which he applied first to academic entomology and then to human sexuality, and the obsessive work ethic that contributed to his death.