Why Men are Taller Than Women on Average

 

When thinking about the average height of everyone in your family, what can you notice? Is dad taller than mom? Or maybe your brother is taller than your sister. How about your circle of friends? Do the boys tend to tower over most of the girls? Recent research has found that there is a specific gene that helps explain this phenomenon.

A study drawn from the genetic data of approximatley 1 million people, published in the Proceedings of the National Academy of Sciences, found that a gene called the SHOX gene may be responsible for this height discrepancy.

The SHOX gene is a growth-regulating gene found on both the X and Y chromosomes, and is a determining factor of one's height as it helps control bone growth, particularly in the appendages. Thus, differences in how expressed the SHOX in men and women can contribute to the variation in height.

A unique feature about the SHOX gene is that, although it is found on both the X and Y chromosome, it is more active and has a stronger effect when on the Y chromosome. Therefore, in women with two X chromosomes, one X is mostly switched off, meaning the SHOX gene on that chromosome is only partly active. But in men with both an X and a Y chromosome, both copies of the SHOX gene are fully active. This results in a slightly stronger growth-promoting effect, which is believed to contribute the the common association that men are taller than women. 

Of course the SHOX gene is not the only gene that determines height and there are numerous other factors at play. However, this discovery allows us to better understand the mystery that is height differences between men and women.

News Article Source: https://www.usnews.com/news/health-news/articles/2025-05-20/scientists-find-gene-that-helps-explain-why-men-are-taller-than-women

More on the SHOX Gene: https://medlineplus.gov/genetics/gene/shox/