Many years ago the above two questions would get a resounding "yes" or a strong "maybe." 

Next time you are at a museum look at the old masters paintings of families – the children are dressed in adult-like clothing and their proportions are adult-like. 

Newborn baby – note the large head!

Did the early artists "see" a small head when painting – or was it such a prevalent attitude that the artist intentionally "missed" the actual size of the child's head and body in order to appease the family paying for the painting.

Children being seen as something almost entirely different from adults was not a viable notion until the early part of the 1900's – not that long ago.  Yet there are persons today who think children have no ideas of their own and are molded solely by what their parents do to and for them.

Children are different.  Yes they are the same species as the adults who raise them – but how they function;  how they learn, think, and talk follows that child's path of development.  And it's not an adult path.

The way you "see" children affects how you raise them.

There is more about this and other aspects of child development and parenting in my e-book: You Can Totally Screw Up As A Mom And Still Raise Great Kids.