At the 1996 Atlanta Summer Olympics, the last that had cheek swabs, 7 women out of the 3,387 competitors — or about 1 in 480 — were found to have the SRY gene and androgen insensitivity. The typical rate of androgen insensitivity is estimated to be between 1 in 20,000 and 1 in 64,000. Over five Olympic Games, an average of 1 in every 421 female competitors was determined to have a Y chromosome. So women with androgen insensitivity are vastly overrepresented on the world’s largest sporting stage.
Perhaps, then, something about the Y chromosome other than testosterone may be conferring an advantage. Women with androgen insensitivity tend to have limb proportions more typical of men. Their arms and legs are longer relative to their bodies, and their average height is several inches taller than that of typical women.
(Two of the endocrinologists I spoke with said that XY women are also overrepresented in modeling, because they are often very feminine in appearance in addition to being tall with long legs. Before her personal medical information unfortunately landed in the press, the tall, blond Coimbra had been dubbed the “Brazilian Barbie Doll.”)
Are we talking about actual XY women, or instead about XXY women? Because I don’t believe the former exist; unless we’re talking about human chimeras: people who are a fusion of tissues or cells from two siblings.