Multiple legislatures and some sports bodies have addressed the issue of transgender athletes in gendered competition, usually by pointing out that such transgender athletes, especially male to female, have a significant, genetically based advantage. As of now, at least ten state legislatures and other sports governing bodies have created significant policy restrictions on those athletes. Those restrictions typically adopt a simplistic binary policy solution that fails to incorporate important, well-known biological facts. For example, sex at birth is usually, but not always, a simple male or female binary phenomenon; typical birth certificates only allow male or female. Those rare situations in which a newborn exhibits partial male and/or partial female attributes typically get shoehorned into one or the other category. These cases are rare, and very few transgender athletes were born as intersexes. Other biological complexities arise, as pointed out in a recent court ruling in Tucson that temporarily blocked a legislative ban from going into effect by correctly addressing the fact that the relevant biological traits of males and females before puberty are sufficiently similar as to obviate any need to distinguish transgender from cisgender individuals.
A large part of the motivation for these restrictions by authorities lies in the biological fact that individuals who have undergone puberty as a male, by whatever means, typically possess more strength, endurance, and larger size than individuals who have not experienced male puberty. These traits can translate into a competitive sports advantage for trans athletes. Indeed, such advantages accrue to individuals transitioning from male to female post-puberty. In tennis, swimming, high jumping, shot put, basketball, and many other sports, larger size, higher strength, and similar traits provide significant advantages. Adult males typically exhibit 15x the circulating testosterone levels of adult females. That difference matters.
The standard argument in favor of restricting transgender competitors rests on the idea that genetic advantage by transition—male to female—makes for an unfair, competitive situation. In truth, the competitive sports situation encompasses far more complexity than the simple binary bans allow.
Genetic advantage has always been a major part of competitive sports of many types. Human height, for one example, is approximately 80% genetically based. Gymnast Symone Biles has a crucial genetic advantage with her height of 4’8”. Britney Griner, with her 6’9” height, could not successfully compete as a gymnast. Still, she employs her genetic height to great advantage in basketball. Indeed, with this genetic advantage plus her highly developed basketball competence, she might well compete successfully in the NBA as she has in the WNBA. With rare exceptions, great height serves tall individuals very well in basketball. To be fairer genetically, one might (as happens in some circumstances) restrict basketball players to, say, heights of six feet or less. However, the genetic height advantage, within sex or gender, for basketball players and gymnasts has never been deemed unfair. Such advantages play a positive, important role in individual success in several sports. Highly successful professional American Football players, particularly linemen, rely heavily on genetic size for their success but would be genetically disadvantaged in, say, high-jumping or pole-vaulting competitions. Can you imagine Trent Brown or Daniel Faalele, each at 380lbs, successfully competing in the Tour de France?
Several sports have long addressed some of these issues by creating objectively similar competitive classes. Examples include weight categories for boxers, jockeys, and wrestlers. Age-class competitive categories include golf, baseball, and track. The authorities in these areas have clearly and properly eschewed the simplistic binary categorization.
In summary, competitive sports rules at professional, college, high school, and Olympic levels, clearly regard genetic advantage as an acceptable, even necessary, element of competitive sports. The genetic advantage of transgender athletes should not be subjected to an over-simplified set of binary bans or restrictions. Still, such rules should also consider age, testosterone levels, psychological outlooks, and the negative stigma often attached to transgender athletes. We can do much better than these simplistic, binary bans by state legislatures.
Michael Grant is a former military serviceman and an academic with degrees from Texas Tech and Duke University. After serving in the U.S. Air Force during the Vietnam era, he taught Biology for 43 years at the University of Colorado Boulder, focusing on Evolution, Ecology, and Data Analysis. He has written numerous research papers that were published in notable scientific journals. Since his retirement in 2016, he’s been contributing as a Professor and Vice Provost Emeritus at the same university.