Part of the rationale for this change was to move away from associations with gender, and to increase clarity by grounding the classification system in genetics. While the medical community has largely accepted the move, some individuals from intersex activist communities have condemned it. Alternative social and historical definitions of intersex — such as those proposed by the intersex activists — have the potential to do more justice to the lived experience of those affected by such classifications and their consequences. The classification of bodily variations is a complex, messy process. Classifications of variations of sex characteristics, or intersex traits, have changed significantly throughout history.

Intersex people are individuals born with any of several variations in sex characteristics including chromosomes , gonads , sex hormones or genitals that, according to the Office of the United Nations High Commissioner for Human Rights , "do not fit the typical definitions for male or female bodies". Sex assignment at birth usually aligns with a child's anatomical sex and phenotype. The number of births where the baby is intersex has been reported to be as low as 0. Intersex people were previously referred to as " hermaphrodites " or "congenital eunuchs ".

About one in 4, babies show ambiguous genitalia at birth, such as a clitoris that looks like a penis, or vice versa. For the Insights story, " Going Beyond X and Y ," appearing in the June issue of Scientific American, Sally Lehrman talked with noted geneticist Eric Vilain of the University of California, Los Angeles, about the biology of sex determination, gender identity and the psychology and politics behind both. Here is an expanded interview.

Haeberle Original editors: Vern L. Bullough and Bonnie Bullough. Originally published by Garland Publishing Inc.