Humans are a whole lot taller than they used to be. If you’re not convinced by walking into an old building and hitting your head on doorways every few steps, you can also look at the hard data: Today, the average American male is 5’10”, but 100 years ago he was just 5’7”.

If you take it back all the way to the mid-19th century, the difference expands by up to seven inches. With human beings growing more and more every century and every generation, it’s no surprise then that ceiling heights and clothing are becoming harder and harder to keep up to date.

Also, it isn’t just that the average person is a few inches taller. We’re seeing more and more super-tall people. In the NBA, the average player height was 74.32 inches (roughly 6’2”) in 1947 and has steadily increased to 6’7”.

Looking at the Olympics, the fastest runners are 6.4 inches taller than in 1900 and the fastest swimmers are 4.5 inches taller.

It begs the question: Why is this change in height within the human race happening?

Society Values Height: Could Evolution Play A Role?

It’s science. As a whole, society views taller people (especially men) as more authoritative than shorter people. That sounds like a soft conclusion, until you realize that it correlates directly to average salary and the percentage of CEOs at Fortune 500 companies.

Fact is, if you’re tall, people more easily accept you as an authority, which traces back to our caveman roots in which the biggest of us tended to be the alpha that protected the entire tribe.

Since we have no natural predators, the theory of evolution alone only goes so far as to explain why we’re getting taller. As most people have the ability to reproduce, it would be difficult for evolution alone to explain why we’re getting taller so quickly.

Our Nutrition Keeps Getting Better

Human height has remained largely similar from the Stone Age all the way up through the 1800s — so it’s not like height was being naturally selected for in a measurable way.

Our civilization’s advancements in nutrition seem to best explain the surge in height. More advanced countries with better nutrition have enjoyed the highest increases in average height, and the countries with the poorest nutrition tend to remain shorter.

So, it turns out that there isn’t exactly a mystical explanation. If you want to grow up tall, just do what Mom said: Eat your vegetables.