Yawns are more contagious among people with closer relationships.
163
Early American humans hunted car-size armadillos and used their shells for houses.
12
A person will create enough saliva to fill two average size swimming pools during his lifetime.
191
There are times when you're walking that the pressure on your feet exceeds your body weight, and when you're running, it can be three or four times your weight.
62
It takes about 20 seconds for a red blood cell to circle the whole body.
102
On average, there's 100 billion neurons in the human brain.
83
Our brains have a negativity bias and will remember bad memories more than good ones.
15
Every human spent about half an hour as a single cell.
144