Yawns are more contagious among people with closer relationships.
163
Our eyes are always the same size from birth, but our nose and ears never stop growing.
266
The human brain doesn't stop developing until about 25 years old.
102
Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
The human brain uses approximately as much energy as a 10 watt light bulb.
120
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
Poor eyesight (myopia) is associated with higher IQ.
232
Dogs can be trained to identify the scent of lung cancer long before symptoms develop.
190