Yawns are more contagious among people with closer relationships.
163
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
One human hair can support 3 ounces.
191
Your heart will pump about 212 million liters in its lifetime.
26
Staying awake for 17 hours is the same for your body as drinking 2 glasses of wine.
193
When you take a step, you are using up to 200 muscles.
886
Poor eyesight (myopia) is associated with higher IQ.
232