Yawns are more contagious among people with closer relationships.
163
The adult human brain weighs about 3 pounds (1,300-1,400 g).
99
It takes twice as long to lose new muscle if you stop working out than it did to gain it.
127
Every year your body replaces 98% of your atoms.
119
Dogs can be trained to identify the scent of lung cancer long before symptoms develop.
190
The average person's skin weighs twice as much as their brain.
131
Your thumb is about the same size as your nose.
124
