Yawns are more contagious among people with closer relationships.
163
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
Dogs can be trained to identify the scent of lung cancer long before symptoms develop.
190
Quick naps not only improve your alertness, but they also help in decision making, creativity and sensory perception.
149
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
For most people, no matter how hard you pinch the skin on your elbow with your fingers it doesn't hurt.
515