Is Constancy Learned or 
Innately Determined?
A duplicate drawing of the 
woman and man in the 
background of the Capitol’s 
corridor has been placed in the 
foreground.  Despite the 
equality of the visual angles 
the couples subtend, they look 
different in size.

How do we come to possess 
spatial and lightness 
constancies? Almost all 
beginning students of 
perception assume that 
constancy is learned as we 
develop and move around in the 
environment. In doing so, we 
discover that distant objects 
that appear small are actually 
quite large, that slanted things 
that look like ellipses and 
trapezoids are in fact circles 
and squares, and so forth. This 
belief is consistent with the 
popular but erroneous camera 
theory of perception, discussed 
in Chapter 1, and, like it, rests 
on the assumptions that 
perception corresponds with 
the picture the eye “takes” and 
that what is referred to as 
constancy is a matter of 
knowing about things, not a 
matter of how things appear to 
us.