Yawns are more contagious among people with closer relationships.
163
When you are looking at someone you love, your pupils dilate, they do the same when you are looking at someone you hate.
1k
The human brain doesn't stop developing until about 25 years old.
102
One human hair can support 3 ounces.
191
Gorillas can catch human colds and other illnesses.
205
After age 30, the brain shrinks a quarter of a percent (0.25%) in mass each year.
139
Our brains have a negativity bias and will remember bad memories more than good ones.
15
The average sperm cell swims at 8 inches per hour.
4