Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
Yawns are more contagious among people with closer relationships.
163
For most people, no matter how hard you pinch the skin on your elbow with your fingers it doesn't hurt.
515
If your DNA was stretched out it would reach to the moon 6,000 times.
256
Poor eyesight (myopia) is associated with higher IQ.
232
When you get goosebumps and your hair stands, the hair helps to trap air, making you feel warmer by keeping in your body heat.
46
The average sperm cell swims at 8 inches per hour.
76