Yawns are more contagious among people with closer relationships.
163
One human hair can support 3 ounces.
191
Dogs can be trained to identify the scent of lung cancer long before symptoms develop.
190
The human brain doesn't stop developing until about 25 years old.
102
Our eyes are always the same size from birth, but our nose and ears never stop growing.
266
The human brain uses approximately as much energy as a 10 watt light bulb.
120
Staying awake for 17 hours is the same for your body as drinking 2 glasses of wine.
193
Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18