Professor Koopman has assured us that he cannot verify such a figure and has made the following statement “Given the difficulties in ascertaining what is and what is not intersex, and that the figure seems to have come from a press release and that the source of the figure remains unknown and unsubstantiated”.
OII Australia has been able to verify the 4% figure was in fact that used by Dr John Money based on his research – Man & Woman, Boy & Girl: Gender Identity from Conception to Maturity – and was attributed to Professor Koopman in error by journalists and a grant application scribe.
OII remains of the view that no research has yet been conducted that would dispute the research of Dr Anne Fausto-Sterling as a minimum figure of 1.9 % of all live births and that given only people with a medical reason or by chance come to the attention of data collectors the figure is likely to be substantially higher. Money based his number on consideration of those people who had come to his attention through his clinic at the Johns Hopkins Hospital. We take that estimate as an informed opinion rather than researched fact.
OII Australia also maintains that the prevalence figure of children born with visible differences and who are subjected to early medical interventions of 1:2,000 is false and based on a misreading of both Anne Fausto-Sterling’s research and reports by Alice Dreger in the Hastings Center Report. Dreger therein quotes gynecological papers that put intersex births known to be so because of visible differences in genitalia at 1:500.
Anne Fausto-Sterling, Sexing the Body: How Biologists Construct Sexuality (New York: Basic Books, forthcoming 1999), chap. 2; Fausto-Sterling, How Dimorphic Are We? American Journal of Human Genetics (forthcoming); and personal communication. The highest modern-day estimate for frequency of sexually ambiguous births comes from John Money, who has posited that as many as 4 percent of live births today are of “intersexed” individuals (cited in Anne Fausto-Sterling, The Five Sexes, The Sciences 33 : 20-25). Money’s categories tend to be exceptionally broad and poorly defined, and not representative of what most medical professionals today would consider to be “intersexuality”.
One 1993 gynecology text estimates that “in approximately 1 in 500 births, the sex is doubtful because of the external genitalia.” We are persuaded by more recent, well-documented literature that estimates the number to be roughly 1 in 1,500 live births. The frequency estimate goes up dramatically, however, if we include all children born with what some physicians consider cosmetically “unacceptable” genitalia.