Fritz Klein (sex researcher)

Fred "Fritz" Klein (December 27, 1932 – May 24, 2006) was an American psychiatrist and sex researcher who studied bisexuals and their relationships. He helped begin a foundation that promoted bisexual culture. He was an author and editor, as well as the developer of the Klein Sexual Orientation Grid, a scale that measures an individual's sexual orientation. Klein believed that sexual orientation changed over the course of a lifetime and that researches underestimated the number of men that had sexual interactions with both sexes. He mentioned neurolinguistic programming had supplanted other methods to change behavior.

Klein was born in Vienna, Austria, to Orthodox Jewish parents. He and his family fled to New York when he was a child, to escape antisemitism.

He received a BA from Yeshiva University in 1953, and an MBA from Columbia University in 1955. He studied medicine at University of Bern in Switzerland for six years, receiving his MD in 1961. He practiced as a psychiatrist in New York City in the 1970s.

Self-identified as bisexual, Klein was surprised at the lack of literature on his sexuality in the New York Public Library in 1974. That year he founded the Bisexual Forum, the first support group for the bisexual community.

He devised the Klein Sexual Orientation Grid, a multi-dimensional system for describing complex sexual orientation, similar to the "zero-to-six" scale Kinsey scale used by Alfred Kinsey, but measuring seven different vectors of sexual orientation and identity (sexual attractions, sexual behavior, sexual fantasies, emotional preference, social preference, lifestyle and self-identification) separately, as they relate person's past, present and ideal future.

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