INDIVIDUAL DIFFERENCES IN 
CONSTANCY    In constancy 
experiments, subjects 
consistently differ from one 
another. Some tend to match 
on the basis of constancy 
regardless of conditions or the 
kind of constancy tested. 
Others tend consistently to 
stray from full constancy.

    The fact that experimental 
observers are consistent in 
their patterns of matching 
would seem to suggest that some 
characteristic of the individual 
is responsible rather than just 
random variation in the face of 
a difficult task. Yet there is no 
convincing evidence that such 
differences occur in daily life. 
When several people are 
together, do they not typically 
agree about the strikingly huge 
size of the horizon moon, the 
strikingly diminished size of 
houses, trees, and cars seen in 
the valley from a very distant 
mountain, and other such 
perceptual phenomena?