Here is documentation that sticking your lower lip out to pout is a natural phenomenon and not just something kids mimic because they see it on tv.
This is what Violet looks like when she is sad. That’s not her tongue, it’s her lip. Could she stick it out any farther? She sticks it out so far that you can see her gums. She makes this face right before she starts crying.
This particular time she was overtired and wasn’t sure what she wanted. Nothing I offered was making her happy. Clearly the whole world sucked and she needed to go to bed, but we had to leave for preschool pick-up in 20 minutes so she had to suffer it out a bit longer.
It’s hard to be a baby.
But seriously, I had no idea that pouts actually occurred like this naturally. It would take some concentration to make my own lip stick out that far.