Scientists Find Gene That Helps Explain Why Men Are Taller Than Women

Key Takeaways

• A gene called SHOX may explain why men are typically taller than women

• The 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 get a bigger boost, researchers say.

More from this section

Mom in coma after contracting meningitis on Spain vacation

How AI is changing Alzheimer’s and dementia care

Women who stay active can cut risk of early death by half

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 information

Our World in Data has more on human height.

SOURCE: The New York Times, May 19, 2025

What This Means For You

Scientists now understand a bit more about why men are usually taller than women.