Alfred Charles Kinsey (June 23, 1894 – August 25, 1956) was an American biologist and professor of entomology and zoology, who in 1947 founded the Institute for Research in Sex, Gender and Reproduction at Indiana University, now called the Kinsey Institute for Research in Sex, Gender, and Reproduction. Kinsey's research on human sexuality - foundational to the modern field of sexology - profoundly influenced social and cultural values in the United States and many other countries.

Alfred Kinsey was born on June 23, 1894, in Hoboken, New Jersey, to Alfred Seguine Kinsey and Sarah Ann Charles. Kinsey was the eldest of three children. His mother had received little formal education; his father was a professor at Stevens Institute of Technology. His parents were rather poor for most of Kinsey's childhood. Consequently, the family often could not afford proper medical care, which may have led to young Kinsey's receiving inadequate treatment for a variety of diseases including rickets, rheumatic fever, and typhoid fever. This health record indicates that Kinsey received suboptimal exposure to sunlight (the cause of rickets in those days before milk and other foods were fortified with vitamin D) and lived in unsanitary conditions for at least part of his childhood. Rickets, leading to a curvature of the spine, resulted in a slight stoop that was to prevent Kinsey from being drafted in 1917 for World War I.

Kinsey's parents were extremely devout Christians; this left a powerful imprint on Kinsey for the rest of his life. His father was known as one of the most devout members of the local Methodist church and as a result most of Kinsey's social interactions were with other members of the church, often merely as a silent observer while his parents discussed religion with other similarly devout adults. Kinsey's father imposed strict rules on the household including mandating Sunday as a day of prayer (and little else), outlawing social relationships with girls. As a child, Kinsey was forbidden to learn anything about the subject that was to later bring him such fame.