Subject: Geometrical perspective - why is it absent in many cultures?

I'm interested in the neuronal basis for understanding and drawing a geometrical
perspective.

Greeks and Romans were known to use geometrical perspective in their fresco
paintings. This perspective reappears in the Renaissance in the 15th century and
persists in European/Western culture to this day. 

There are cultures, however, where it wasn't/isn't a widely-accepted phenomenon,
or never appeared at all (medieval Europe; several Asian cultures like China;
ancient Egypt...)
So I was wondering... Didn't they understand how to draw in geometrical
perspective? Or did they aim to depict something else - maybe they weren't
trying to draw realistically? 

Medieval Europe is particularly interesting. Paintings show towns and buildings,
but the images are 'off'. Sometimes reverse perspective was used:  was that an
unsuccessful attempt at being realistic or did such perspectives serve other
purposes? 
Also, even though figures in the background appear smaller, all people were
often drawn the same size – allegedly because the artist knew an actual person
couldn't shrink.

Today, young teenagers are able to understand geometrical perspective and use it
in their drawings. So, if this doesn't occur in every culture, is it because we
are exposed to such images at a very young age..? Could someone reared in a
different environment actually fail to develop that ability?

I've asked a lot of questions so I'll try to sum it up: HOW CAN WE EXPLAIN THE
ABILITY OF UNDERSTANDING AND USING GEOMETRICAL PERSPECTIVE IN TERMS OF
NEUROANATOMY AND BRAIN DEVELOPMENT? Regarding development, is nature or nurture
more important?

Re: Geometrical perspective - why is it absent in many cultures?