Why World Athletics Is Right to Use the SRY Gene Test

The scientist who discovered the SRY gene denounced its use in sports sex testing. Here’s why he’s wrong.

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About the Author

Dr. Colin Wright is an evolutionary biology PhD, Manhattan Institute Fellow, and CEO/Editor-in-Chief of Reality’s Last Stand. His writing has appeared in The Wall Street Journal, The Times, the New York Post, Newsweek, City Journal, Quillette, Queer Majority, and other major news outlets and peer-reviewed journals.

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World Athletics recently announced a major change to its eligibility rules for women’s sport. Starting September 1, 2025, any athlete who wants to compete in the female category at world-ranking events will be required to take a once-in-a-lifetime genetic test for the SRY gene. This gene, located on the Y chromosome in mammals, plays a central role in male development. Its presence initiates a cascade of events that leads to the formation of testes, which define the male sex due to it’s function to produce sperm, and produce testosterone, the hormone largely responsible for male-typical physiology, including the muscle mass, strength, and speed advantages that persist even after puberty. World Athletics says the SRY test is “a reliable proxy for determining biological sex,” and they’re using it to protect the integrity of the female category.

Most biological realists view this policy as a sensible and long-overdue safeguard for women’s sport. But others—especially those opposed to almost any eligibility rules for women’s sport—are determined to find reasons to reject it, and have now seized on what they view as their trump card. Andrew Sinclair, the geneticist who first identified the SRY gene in 1990, has written an article in The Conversation blasting the policy as “misguided” and claiming that “science does not support [the] overly simplistic assertion” that the SRY gene is a reliable proxy for sex. “I should know,” he adds, “because I discovered the SRY gene on the human Y chromosome in 1990. For 35 years I have been researching it and other genes required for testis development.”

Among gender activists, this was greeted like a mic-drop moment. The man who discovered the very gene now being used in the test denouncing its use in sport. In their world, the appearance of scientific authority often carries more weight than rigorous reasoning or careful engagement with the evidence. The idea seems to be that because Sinclair discovered the gene, his opinion on its policy use is automatically decisive. But discovering the gene is not the same as understanding how to design eligibility criteria for sport. As his piece unfolds, it’s obvious he has neither read World Athletics’ new rules nor grasps what the female category is meant to protect.