Kinsey Scale

Also called the Heterosexual-Homosexual Rating Scale, the Kinsey Scale was introduced by sex researcher Alfred Kinsey and his colleagues in Sexual Behavior in the Human Male (1948) and used again in the 1953 female volume. It rates a person's sexuality from 0, meaning exclusively heterosexual, to 6, meaning exclusively homosexual, with the numbers in between reflecting varying degrees of attraction to both. For its era it was groundbreaking, using survey research to challenge the idea that people are simply gay or straight. The scale has real limits: it does not capture asexuality, romantic orientation, or gender identity. Even so, it remains one of the most historically influential frameworks for thinking about sexual orientation as a continuum.