The Kinsey scale, also called the Heterosexual–Homosexual Rating Scale, attempts to describe a person's sexual experience or response at a given time. It uses a scale from 0, meaning exclusively heterosexual, to 6, meaning exclusively homosexual. In both the Male and Female volumes of the Kinsey Reports, an additional grade, listed as "X", was used to mean "no socio-sexual contacts or reactions". The reports were first published in Sexual Behavior in the Human Male (1948) by Alfred Kinsey, Wardell Pomeroy and others, and were also prominent in the complementary work Sexual Behavior in the Human Female (1953).
- http://www.kinseyinstitute.org/research/ak-hhscale.html "Kinsey's Heterosexual–Homosexual Rating Scale" The Kinsey Institute.