I am sure of one thing. People rarely choose to notice the exaggeration that exists in the world around us, and we typically have a rigid view of human anatomy compared to even what is really going on. Thanks, left brain.
Let's take a look at a simple example:
Did you catch that?
|Whoa, is his leg breaking backwards?|
If this happens in reality, we must at least present the viewer with the shapes and forms that exist. And then we exaggerate for clarity. To distill something down to its essence.
A couple others, slightly off topic but related:
Keith Lango - Audience Preferences