"The cumulative evidence of our study ... is consistent with the view that gender dysphoria is a disorder of the sense of self as has been proposed by Beitel (1985) or PfÑfflin (1993). The central problem in our patients is about identity and the self in general and the transsexual wish seems to be an attempt at reassuring and stabilizing the self-coherence which in turn can lead to a further destabilization if the self is already too fragile. In this view the body is instrumentalized to create a sense of identity and the splitting symbolized in the hiatus between the rejected body-self and other parts of the self is more between good and bad objects than between masculine and feminine." Freud, Kraft-Ebbing, and Fliess suggested that we are all bisexual to a certain degree. As early as 1910, Dr. Magnus Hirschfeld argued, in Berlin, that absolute genders are "abstractions, invented extremes". The consensus today is that one's sexuality is, mostly, a psychological construct which reflects gender role orientation. Joanne Meyerowitz, a professor of history at Indiana University and the editor of The Journal of American History observes, in her recently published tome, "How Sex Changed: A History of Transsexuality in the United States", that the very meaning of masculinity and femininity is in constant flux. Transgender activists, says Meyerowitz, insist that gender and sexuality represent "distinct analytical categories". The New York Times wrote in its review of the book: "Some male-to-female transsexuals have sex with men and call themselves homosexuals. Some female-to-male transsexuals have sex with women and call themselves lesbians. Some transsexuals call themselves asexual." So, it is all in the mind, you see. This would be taking it too far. A large body of scientific evidence points to the genetic and biological underpinnings of sexual behavior and preferences. The German science magazine, "Geo", reported recently that the males of the fruit fly "drosophila melanogaster" switched from heterosexuality to homosexuality as the temperature in the lab was increased from 19 to 30 degrees Celsius. They reverted to chasing females as it was lowered. The brain structures of homosexual sheep are different to those of straight sheep, a study conducted recently by the Oregon Health & Science University and the U.S. Department of Agriculture Sheep Experiment Station in Dubois, Idaho, revealed. Similar differences were found between gay men and straight ones in 1995 in Holland and elsewhere. The preoptic area of the hypothalamus was larger in heterosexual men than in both homosexual men and straight women.