Fritz Klein (sex researcher)

Fritz Klein (1932-2006) was an Austrian-American psychiatrist and sex researcher, best known for creating the Klein Sexual Orientation Grid (KSOG). He founded the Journal of Homosexuality in 1974 and the Bisexual Forum (later the American Institute of Bisexuality) in 1998.

Klein was born in Vienna, Austria, and fled to the United States with his family in 1938 to escape Nazi persecution. He received his medical degree from the University of Bern in Switzerland.

His work challenged the Kinsey Scale, which primarily focused on sexual behavior, by suggesting that sexual orientation is a more complex and fluid concept. The KSOG assesses past, present, and ideal sexual behavior, attraction, fantasy, emotional preference, social preference, self-identification, and lifestyle, allowing for a more nuanced understanding of an individual's sexuality over time. Each of these parameters is rated on a scale of 1 to 7, allowing for a much broader range of sexual expression than a simple homosexual-heterosexual binary.

Klein's work was instrumental in advancing the understanding and acceptance of bisexuality. He argued against the misconception of bisexuality as merely a phase or a midpoint between homosexuality and heterosexuality, asserting its validity as a distinct sexual orientation. His writings and activism helped to create a space for bisexual individuals to identify and connect with one another.

He authored several books, including "The Bisexual Option: A Concept of One Hundred Percent Intimacy" (1978), "Bisexualities: Theory and Research" (1985), and "The Second Bisexual Book: Essays on Human Sexuality" (1993). His work continues to be influential in the fields of sexology, psychology, and LGBTQ+ studies.