Look at these

Now look at this version of the photograph.  All I did was cut out the figure in the white t-shirt and paste him down near the feet of some of the people in the front.  The figures are exactly the same size.  Measure them!  This photograph represents a variation of a classic demonstration of the power of size constancy done by Boring (1964).

Just to prove I have not maniuplated these figures, I have developed three additional versions of this demonstration:

• Version with several copies of the walker.

• An animated version (may not work properly with Netscape).

• An interactive figure where you can play with size constancy cues.

Check these pages out for some interesting effects.

Reference:

Boring, E. G. (1964). Size constancy in a picture.  American Journal of Psychology, 77, 494-498.

Copyright, 1999, John H. Krantz, all rights reserved.