Yawns are more contagious among people with closer relationships.
163
A human brain produces as many as 12,000 to 50,000 thoughts per day, depending on how deep a thinker a person is.
23
It takes about 20 seconds for a red blood cell to circle the whole body.
102
In 30 minutes, the average body gives off enough heat (combined) to bring a half gallon of water to boil.
198
Having sex can make a woman look younger and more attractive due to the release of estrogen and collagen.
346
A man's beard grows fastest when he anticipates sex.
239
It took 200,000 years for humans to reach 3 billion in number. It took 40 years for the next 3 billion.
11
