Measuring an individual's sexual orientation

Measuring an individual's sexual orientation
Varying definitions and strong social norms about sexuality can make sexual orientation difficult to quantify. Researchers may use different markers of sexual orientation, including self-labeling, sexual behaviour, sexual fantasy or a pattern of erotic arousal. A clinical measurement may use penile or vaginal photoplethysmography, where genital engorgement with blood is measured in response to exposure to different erotic material.[4] In 1995, two researchers argued that due to a lack of research on change over time, there is a limitation on current conceptualizations of sexual orientation. They did not abandon the concept of sexual orientation, but concluded that "given such significant measurement problems, one could conclude there is serious doubt whether sexual orientation is a valid concept at all," and warned against increasing politicization of this area.[5]
From at least the late-19th century in Europe, there was speculation that the range of human sexual response looked more like a continuum than two or three discrete categories. 28-year-old Berlin sexologist Magnus Hirschfeld published a scheme in 1896 that measured the strength of an individual's sexual desire on two independent 10-point scales, A (homosexual) and B (heterosexual).[6] A heterosexual individual may be A0, B5; a homosexual individual may be A5, B0; An asexual would be A0, B0; and someone with an intense attraction to both sexes would be A9, B9.
Fifty years later, American sexologist Alfred Kinsey wrote in Sexual Behavior in the Human Male (1948):
Males do not represent two discrete populations, heterosexual and homosexual. The world is not to be divided into sheep and goats. It is a fundamental of taxonomy that nature rarely deals with discrete categories... The living world is a continuum in each and every one of its aspects. While emphasizing the continuity of the gradations between exclusively heterosexual and exclusively homosexual histories, it has seemed desirable to develop some sort of classification which could be based on the relative amounts of heterosexual and homosexual experience or response in each history... An individual may be assigned a position on this scale, for each period in his life.... A seven-point scale comes nearer to showing the many gradations that actually exist.
– [7]
The Kinsey scale measures sexual orientation from 0 (exclusively heterosexual) to 6 (exclusively homosexual), with an additional category, X, for those with no sexual attraction to either women or men. Unlike Hirschfeld's scale, the Kinsey scale is one-dimensional. Simon LeVay writes, "it suggests (although Kinsey did not actually believe this) that every person has the same fixed endowment of sexual energy, which he or she then divides up between same-sex and opposite-sex attraction in a ratio indicative of his or her own sexual orientation.
http://en.wikipedia.org/wiki/Sex_education