I use sex-gender in these pages to encompass the biological, psychological, cultural and other characteristics presumed to distinguish between women and men, or females and males. I borrow this usage from Edward Stein, author of The Mismeasure of Desire: The Science, Theory, and Ethics of Sexual Orientation. Stein adopted this usage to facilitate his discussion of issues of sexual orientations as indexed to sex and gender while avoiding the assumptions implicit in conventional usage of and distinctions between the terms sex and gender.