When Italian boxer Angela Carini reported that she had “never felt a punch like that” after conceding to Algeria’s Imane Khelif 46 seconds after their Olympic bout began, social media exploded with accusations. Elon Musk and J.K. Rowling chimed in, accusing Khelif of being a man posing as a woman to cheat.
The case highlights what is wrong with Musk, Rowling and others who think of themselves as bravely opposing excess political correctness. They are too in love with their own assumptions and superficial judgements. Khelif’s jawline and strong torso might look stereotypically masculine, but biological sex is about more than looks — and is sometimes more complex than chromosomes.
Consider Jeffrey Eugenides’ Pulitzer Prize-winning novel Middlesex, in which a Greek-American girl named Callie grows up as a pretty, happy child until, as a teenager, her height shoots up and she develops a mustache. As a teenager, Callie is not sure if she is a boy or a girl, and the girl who loves her is not sure if she is gay or straight. At first, their love transcends those identity concerns. I read the book years ago, but it is hard to forget a story like that.
Eugenides was not taking poetic license. The character is based on the author’s meticulous study of a real genetic disorder called 5-alpha-reductase deficiency, which is rare, but somewhat more common in a few parts of the world, including Greece and the Dominican Republic.
An enzyme, 5-alpha-reductase is necessary in the chain of molecular level events leading male embryos — those with a Y chromosome — to grow a penis. The disorder can lead to genetically male (XY) babies emerging into the world looking female and being classified as girls.
Two-time 800m champion Castor Semenya reportedly has a Y chromosome and 5-alpha-reductase deficiency, which has led to endless controversy about her eligibility to compete in women’s events.
Khelif last year was disqualified from a championship event based on a sex test of undisclosed nature, but the International Olympic Committee says she meets their criteria. Some reports say she was disqualified for having a Y chromosome, others because her testosterone level is above a particular threshold.
I do not want to speculate on which it was, but suffice it to say there are a number of ways an XY individual might develop what looks like female genitalia, or an XX individual might have male-like testosterone levels.
Our system of sex determination is not simple. Different animals use other kinds of sex chromosomes — in birds, the females are ZW and males are ZZ, while in some amphibians and reptiles, there are no genetic differences between the sexes and temperature at a critical stage in egg development determines sex. The duck-billed platypus uses a system of 10 sex chromosomes.
Humans use a system of XX for female and XY for male. Embryos all start out with a sort of starter kit for the reproductive parts for both sexes, and a series of activated genes and hormonal surges usually steers things in one direction or the other. Usually, but not always.
A number of genetic mutations can interfere with different stages of that process, leading to differences of sexual development — in anywhere from 1,000 to 4,500 live births. (That makes such sex differences vastly more common than going to the Olympics.) Some babies develop from two early embryos that merged; if those embryos were opposite sex, the baby might have a combination of male and female traits.
Among Olympians, it is more likely we would see people with unusual physical traits. The Olympics and other elite sporting events select for extreme body types — people who are unusually strong, incredibly tall or short, but extremely powerful. They might be wildly fast or insanely flexible, not to mention extraordinarily determined and capable of overcoming pain.
Women’s bodies normally produce testosterone — some more than others — and certain sports likely favor those with a higher level.
This Olympic flap comes at a time of confusion and disagreement about the nature of sex and gender, but there is no excuse for bullying or aiming cheating accusations at athletes who do not conform to expectations. Things are not always what they appear on the surface.
If the current rules allowed Imane Khelif to compete, then she deserves her medal and the world’s admiration.
F.D. Flam is a Bloomberg Opinion columnist covering science. She is host of the Follow the Science podcast. This column does not necessarily reflect the opinion of the editorial board or Bloomberg LP and its owners.
Congratulations to China’s working class — they have officially entered the “Livestock Feed 2.0” era. While others are still researching how to achieve healthy and balanced diets, China has already evolved to the point where it does not matter whether you are actually eating food, as long as you can swallow it. There is no need for cooking, chewing or making decisions — just tear open a package, add some hot water and in a short three minutes you have something that can keep you alive for at least another six hours. This is not science fiction — it is reality.
A foreign colleague of mine asked me recently, “What is a safe distance from potential People’s Liberation Army (PLA) Rocket Force’s (PLARF) Taiwan targets?” This article will answer this question and help people living in Taiwan have a deeper understanding of the threat. Why is it important to understand PLA/PLARF targeting strategy? According to RAND analysis, the PLA’s “systems destruction warfare” focuses on crippling an adversary’s operational system by targeting its networks, especially leadership, command and control (C2) nodes, sensors, and information hubs. Admiral Samuel Paparo, commander of US Indo-Pacific Command, noted in his 15 May 2025 Sedona Forum keynote speech that, as
In a world increasingly defined by unpredictability, two actors stand out as islands of stability: Europe and Taiwan. One, a sprawling union of democracies, but under immense pressure, grappling with a geopolitical reality it was not originally designed for. The other, a vibrant, resilient democracy thriving as a technological global leader, but living under a growing existential threat. In response to rising uncertainties, they are both seeking resilience and learning to better position themselves. It is now time they recognize each other not just as partners of convenience, but as strategic and indispensable lifelines. The US, long seen as the anchor
Kinmen County’s political geography is provocative in and of itself. A pair of islets running up abreast the Chinese mainland, just 20 minutes by ferry from the Chinese city of Xiamen, Kinmen remains under the Taiwanese government’s control, after China’s failed invasion attempt in 1949. The provocative nature of Kinmen’s existence, along with the Matsu Islands off the coast of China’s Fuzhou City, has led to no shortage of outrageous takes and analyses in foreign media either fearmongering of a Chinese invasion or using these accidents of history to somehow understand Taiwan. Every few months a foreign reporter goes to
RSS