It took 200,000 years for humans to reach 3 billion in number. It took 40 years for the next 3 billion.
11
When you kiss someone for the first time, you get a spike in the neurotransmitter dopamine, making you crave more.
23
Yawns are more contagious among people with closer relationships.
163
Your heart will pump about 212 million liters in its lifetime.
26
Our Right Lungs takes more air than our left lung.
194
The adult human brain weighs about 3 pounds (1,300-1,400 g).
99
In ancient Egypt, priests plucked EVERY hair from their bodies, including their eyebrows and eyelashes.
130
Our brains have a negativity bias and will remember bad memories more than good ones.
15