Today’s Wonder of the Day was inspired by Summer from AL. Summer Wonders, “Why am I the shortest peoples” Thanks for WONDERing with us, Summer!

How tall are you? That's a question that many kids ask each other from the earliest moments they meet each other in school. Height is one way we size each other up.

As kids begin to grow, parents and doctors use height as one way to determine whether kids are growing appropriately. Proud parents mark their children's height on the back of a door, keeping tabs on each inch as a new milestone.

Kids look forward to growing taller. For some kids, getting taller means they can finally enjoy that one ride at their favorite amusement park. For others, added height means they can perform better at their favorite sport. Others may want to be taller simply to make it easier to reach the cookies on the top shelf of the kitchen cupboard!

Several Wonder Friends have WONDERed who the tallest person in the world is. That can be a tricky question, since it can change from time to time. So, we'll take a look at who the tallest person alive today is, as well as who is the tallest person to have ever lived.

According to the Guinness Book of World Records, the tallest person in the world who is alive today is Sultan Kösen from Ankara, Turkey. When officially measured, Sultan stood an incredible eight feet, three inches tall!

How incredible is Sultan's height? He is believed to be one of only about 10-15 people in the history of the world to measure over eight feet tall. Sultan took the title of World's Tallest Man from Xi Shun of China, who stood seven feet, nine inches tall.

Like many of the world's tallest people, Sultan's height is caused by a physical condition called pituitary gigantism. This condition causes Sultan's pituitary gland to secrete too much growth hormone. In fact, he might still be growing today if he had not had brain surgery to remove the tumor that had been affecting his pituitary gland!

Sultan has also held world records for the world's largest hands and largest feet. He recently got married to a woman who is over two and a half feet shorter than he is! He had to have a suit custom made, and his shoes were a whopping size 28!

Sultan is not the tallest person to have ever lived, though. That title goes to American Robert Wadlow from Illinois. Wadlow died in 1940. His official height was an incredible eight feet, 11 inches. That's right! Wadlow was just an inch shy of standing nine feet tall!

Great heights aren't just limited to men, however. The tallest woman to ever live is believed to be Zeng Jinlian, who stood almost eight feet, two inches — the only woman known to have ever surpassed eight feet in height.

Could you imagine an entire country full of people who are really tall? Some countries around the world are known for having citizens who are particularly tall. Statistically, the country with the tallest people is the Netherlands. The average height of Dutch adults is approximately six feet, one inch. Denmark comes in a close second, with an average height of six feet. The United States once claimed the title of tallest country, but American males now average just five feet, nine inches tall.

Wonder What's Next?

Tomorrow’s Wonder of the Day is full of grunts, squeals, chirps, and a variety of other interesting sounds!