By weight, Bone is five times stronger than steel.
417
A human being loses an average of 40 to 100 strands of hair a day.
133
The human brain is more active during sleep than during the day.
28
Only humans shed emotional tears.
331
Crying literally alleviates stress and uniquely allows humans to decrease feelings of anger and sadness.
24
It takes twice as long to lose new muscle if you stop working out than it did to gain it.
127
Coughing can cause air to move through your windpipe faster than the speed of sound - over a thousand feet per second!
197
Yawns are more contagious among people with closer relationships.
163