Yawns are more contagious among people with closer relationships.
163
When you take a step, you are using up to 200 muscles.
886
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
The human brain doesn't stop developing until about 25 years old.
102
One human hair can support 3 ounces.
191
Quick naps not only improve your alertness, but they also help in decision making, creativity and sensory perception.
149