Today’s Wonder of the Day was inspired by Miss from San Antonio, TX. Miss Wonders, “How many hairs do you have on your head?” Thanks for WONDERing with us, Miss!

How high can you count? Can you make it to 100? How about 1,000? Have you ever tried to count the stars in the sky? How about the leaves on a tree? Maybe you’ve even tried to count the hairs on your head!

Counting the hairs on your head would be very difficult. Many have tried, but most people give up after losing count or—let’s face it—growing bored! However, scientists do have an estimate. On average, people have more than 100,000 hairs on their heads.

Of course, this number varies from person to person. Some people have much more hair than others. There is some evidence that hair count may correlate to hair color, with blonde people having the most hair and redheads the least.

What causes hair loss? Many factors can contribute. Stress, illness, and some medications can all cause hair loss. It also runs in families—often, genes contribute to loss of hair and baldness. Additionally, many people simply lose hair as they grow older.

Haircare practices can also affect the number of hairs on your head. Harsh chemicals and styling routines can lead to hair loss. Regular shampooing and conditioning can help keep your hair healthy. To avoid damage, it’s also important to be gentle when brushing or combing hair.

Hair loss is not the same as regular shedding. On average, people shed 50-100 hairs per day. This is normal and a healthy part of the hair growth process. If you’re regularly losing more hair than average, talk to a trusted adult. They can help you decide whether to seek help from a doctor.

Have you ever WONDERed why humans have hair on their heads, anyway? After all, most other mammals have thick fur covering their entire bodies. While humans grow small, fine hairs on much of their skin, it’s much denser on the top of the head.

Scientists say the answer comes down to evolution. Humans likely evolved without fur because they have more sweat glands than other mammals. Less hair also meant fewer opportunities for parasites like lice and mites to live on the human body. 

Since humans walk upright on two legs, the top of their heads still needs protection from the Sun. This is why people have more hair on their heads than on the rest of their bodies. This hair also helps retain heat in cold weather and maintain a healthy body temperature.

Have you ever tried to count the hairs on your head? If so, you know it’s quite the task! We hope you take steps to keep all the hairs on your head healthy—no matter how many there are!

Standards: NGSS.LS1.A, CCRA.R.4, CCRA.L.1, CCRA.L.2, CCRA.R.10, CCRA.R.1, CCRA.SL.1, CCRA.W.2, CCRA.SL.3, NCAS.A.1, NCAS.A.2, NCAS.A.3

Wonder What's Next?

Tomorrow’s Wonder of the Day may be a bit of a stretch!