Why do we yawn?

What is a notable characteristic of yawning that can spread from person to person?

• It is a reflex action.

• It is contagious.

• It is a sign of hunger.

• It is a way to stretch muscles.

What is currently known about why humans yawn?

• It helps us get more oxygen into our bodies.

• It is a way for our brains to cool down.

• The exact reason is still unknown to scientists.

• It is a sign that we are always bored.

Approximately how many times a day do most people yawn?

• Less than 5 times.

• Around 15-16 times.

• More than 50 times.

• Only when they are extremely tired.

When do humans typically begin to yawn?

• Only after they are born.

• During their teenage years.

• Before they are born, while still in the womb.

• When they are very old.