Did you know?
Facial expressions of emotion are the most important and complex signal system humans have: the human face has about 20 muscles which are capable of making thousands of different facial expressions.
Evidence also shows that facial expressions begin in utero; data shows that laughing and smiling begin in the womb as early as 24 weeks and are very prevalent by 32.
Take a look at this interesting video of how faces develop in the womb and how the development of human faces are unique to our species.