For most people, no matter how hard you pinch the skin on your elbow with your fingers it doesn't hurt.
515
Yawns are more contagious among people with closer relationships.
163
Dogs can be trained to identify the scent of lung cancer long before symptoms develop.
190
Staying awake for 17 hours is the same for your body as drinking 2 glasses of wine.
193
The human brain doesn't stop developing until about 25 years old.
102
An average heart beats 100,000 times a day, pumping some 2,000 gallons of blood through its chambers. Over a 70-year life span, that adds up to more than 2.5 billion heartbeats.
73
Our eyes are always the same size from birth, but our nose and ears never stop growing.
269
Poor eyesight (myopia) is associated with higher IQ.
232