In 1948, Alfred Kinsey developed the Kinsey scale for the purposes of his famous study on the prevalence of homosexuality in the general population. It was published in the then-revolutionary book Sexual Behavior in the Human Male, along with Kinsey's findings from using this scale.
Sometime later, in 1980, Fritz Klein published The Bisexual Option wherein he expanded this scale to a two-dimensional grid of scales. Where the Kinsey scale asked only how many homosexual experiences an individual has had up to the present, the Klein Sexual Orientation Grid (KSOG) takes several different aspects of one's sexual orientation into account.
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| Past | Present | Ideal |
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|A) Sexual attractions | | | |
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|B) Sexual behavior | | | |
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|C) Sexual fantasies | | | |
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|D) Emotional preference | | | |
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|E) Social preference | | | |
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|F) Lifestyle preference | | | |
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|G) Self-identification | | | |
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A-E: F-G:
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1 Other sex only 1 Heterosexual only
2 Other sex mostly 2 Heterosexual mostly
3 Other sex somewhat more 3 Heterosexual somewhat more
4 Both sexes equally 4 Heterosexual and homosexual
equally
5 Same sex somewhat more 5 Homosexual somewhat more
6 Same sex mostly 6 Homosexual mostly
7 Same sex only 7 Homosexual only
Definitions:
- Sexual attraction: Who turns you on? Who do you find attractive as a real or potential partner?
- Sexual behavior: Who are your sexual contacts or partners?
- Sexual fantasies: Whom do you enjoy fantasizing about in erotic daydreams?
- Emotional preferences: With whom do you prefer to establish strong emotional bonds?
- Social preference: Which sex do you prefer to spend your leisure time with, and with which sex do you feel most comfortable?
- Self-identification: How do you think of yourself?
- Lifestyle preference: What is the sexual identity of the people with whom you socialize?
- Past: Your life up to 12 months ago
- Present: The most recent 12 months
- Ideal: What do you think you would eventually look like?
Some researchers after Klein have added "political identity" as an eighth category to score.
There is no "final score" on this grid, although you can add up all the numbers or calculate an average from them. The idea is only to understand exactly how dynamic a person's sexual orientation can be, as well as how fluid it can be over a person's lifespan. While a person's number of actual homo/heterosexual encounters may be easy to categorize, their actual orientation may be completely different. Simple labels like "homosexual", "heterosexual", and "bisexual" need not be the only three options available to us.