It has sometimes been the goal of sexological science to identify not the causes of sexual orientation properly speaking but an objective way of distinguishing people according to traits they have in virtue of their sexual orientation, whether these traits are anatomical, behavioral, or psychological in kind and whether or not they play a causal role in a person's erotic interests. Distinctive traits in brain structure or finger skin ridges would be of interest not only to researchers wanting to know merely for the sake of knowing whether such differences exist, they would also be of considerable interest to those people and institutions who want an objective mechanism for identifying gay people. Since the 1940s, for example, the U.S. military has worked assiduously to find an effective way of excluding gay people from its ranks. In Coming Out Under Fire: The History of Gay Men and Women in World War Two historian Allan Bérubé describes a number of efforts by which military psychiatrists and administrators tried to distinguish straight people from those tainted to various degrees with homoeroticism. 1 In this chapter I will describe how the military might use a sexual orientation test were one available. I will then describe the extent to which current research offers the prospect of a sexual orientation test. No definitive sexual orientation test is to be found in the current research data, but it may nevertheless come to pass that some more or less objective indicator of erotic interests might be found that could be used in testing military personnel, job applicants, and even marriage partners.
While prejudicial uses of any such test are the usual topic of discussion in this area, it should not be assumed that a test must always and only work to the disadvantage of gay people. To make this latter point I will describe some hypo-