It took 200,000 years for humans to reach 3 billion in number. It took 40 years for the next 3 billion.
11
Females learn to talk earlier, use sentences earlier, and learn to read more quickly than males.
119
The single biggest predictor of love is proximity.
30
Most people smile when they are frustrated, according to a study.
15
Every human spent about half an hour as a single cell.
144
The name "Wendy" was made up for the book Peter Pan!
142