Yawns are more contagious among people with closer relationships.
163
The oldest stone tools found are dated from 2.7 - 2.9 million years ago. The species that made these tools is unknown.
13
Our brains have a negativity bias and will remember bad memories more than good ones.
15
Mushrooms are more closely related to humans than they are to plants.
47
Modern humans first appeared about 200,000 years ago, but record keeping didn't begin until about 6,000 years ago. That means about 97% of human history is lost.
21
If Earth's life was compressed into 1 year, then humans would have been around for only 2 seconds.
15
The world's shortest man measures only 21.5 inches.
73
The average person will go on a date at least 100 times before they finally marry.
33