Yawns are more contagious among people with closer relationships.
163
The average person's skin weighs twice as much as their brain.
131
Your heart will pump about 212 million liters in its lifetime.
26
Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
Your thumb is about the same size as your nose.
124
The human brain doesn't stop developing until about 25 years old.
102
Coughing can cause air to move through your windpipe faster than the speed of sound - over a thousand feet per second!
197