There is an explanation of 
Boring’s findings about 
distance, and perhaps the 
reader’s own observations, that 
still allows us to consider the 
apparent-distance theory 
seriously. When asked in which 
position the moon appears to be 
closer, the observer is 
comparing moons that already 
appear to be different in size. 
Because relative size is a cue to 
distance and because we tend to 
believe that objects appear to 
diminish in size as they recede 
into distance, the observer may 
conclude from the fact that the 
moon appears larger on the 
horizon that it also appears 
closer. This conclusion about 
distance is not so much the 
result of a genuine perceptual 
cue as it is a product of a 
thought process or judgment. A 
test of the reasoning is to 
modify Boring’s observation 
about the apparent distances to 
the moons by eliminating the 
moons from view. Observers 
were asked which region of the 
sky appeared to be farther away. 
Virtually all said it was the sky 
at the horizon.