Key TakeawaysA gene called SHOX may explain why men are typically taller than womenThe study used genetic data from nearly 1 million people in the U.S. and U.K.Researchers found that an extra Y chromosome increases height more than an extra X.TUESDAY, May 20, 2025 (HealthDay News) — Men are usually about five inches taller than women, but scientists have long wondered why. Now, a new study points to a possible reason: A gene called SHOX.The study — published May 19 in the Proceedings of the National Academy of Sciences — was drawn from genetic data from roughly 1 million people, The New York Times reported. Researchers looked at information from three large biobanks in the U.S. and the U.K.They focused on a small group of people with either an extra or missing X or Y chromosome. These rare conditions gave researchers a chance to examine how extra copies of the SHOX gene affect height. They found that people with an extra Y chromosome were taller than those with an extra X chromosome. That suggests the SHOX gene, which appears on both the X and Y chromosomes, has a stronger effect when it’s on the Y, according to a report from The Times.Here’s why: In women, who have two X chromosomes, one is mostly inactive and the SHOX gene is only partly active. In men, who have one X and one Y, both versions of the SHOX gene are fully active. In other words, the gene gives men a bigger boost, researchers say.That slightly larger gene effect explains about one-quarter of the average height difference between men and women, study senior author Matthew Oetjens, told The Times. He's a genetics researcher at Geisinger College of Health Sciences in Danville, Pa.The rest of the height difference likely comes from other genes and from male sex hormones, Oetjens added.Eric Schadt, a genetics expert at Mount Sinai in New York City, called the findings "definitely cool."“It is a great use of these biobanks to uncover what is still somewhat of a mystery,” he said. “Even though the effect is modest, it does explain 20 percent or so of the height difference.”More informationOur World in Data has more on human height.SOURCE: The New York Times, May 19, 2025 .What This Means For YouScientists now understand a bit more about why men are usually taller than women..Sign up for our weekly HealthDay newsletter