Fritz Klein

Fred (Fritz) Klein (December 27, 1932 – May 24, 2006) was an American sex researcher, psychiatrist, pioneer of the bisexuality movement, and inventor of the Klein Sexual Orientation Grid.

Life
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 anti-semitism. He received a Bachelor of Arts from Yeshiva University in 1953, and an MBA from Columbia University in 1955. He studied medicine at Bern University in Switzerland for six years, receiving his MD in 1961.

He practiced as a psychiatrist in New York in the 1970s. As a self-identified bisexual, he was surprised at the lack of literature on his sexuality in the New York public library in 1974. He was inspired to place an advertisement in the Village Voice and founded the Bisexual Forum. 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, fantasies, emotional preference, social preference, lifestyle and self-identification) separately, as they relate to a person's past, present and ideal future.

He published The Bisexual Option: A Concept of One Hundred Percent Intimacy  in 1979, based on his research, the world's first real psychological study of bisexuality. He also co-authored Man, His Body, His Sex in 1978, and published Bisexualities: Theory and Research in 1986 and Bisexual and Gay Husbands: Their Stories, Their Words in 2001. He published a novel, Life, Sex and the Pursuit of Happiness in 2005.

Klein moved to San Diego in 1982, founded a second Bisexual Forum and founded the Journal of Bisexuality. He remained its editor until his death. He founded the American Institute of Bisexuality (AIB), also known as the Bisexual Foundation, in 1998 to encourage, support and assist research and education about bisexuality.

He was diagnosed with cancer, and underwent surgery as a result. He died unexpectedly at home following a cardiac arrest, aged 73. He was survived by his life partner, Tom Reise. He donated his body to science.