Look at the picture and you'll notice that on the right is a calm person and on the left an angry one, then step back at 4 meters (about) and look at the picture from the distance, it is the contrary, the calm one is on the left side, and the angry one on the right!www.ddhw.com
It was done by Phillippe G.Schynsand Aude Olivafrom Glasgow university.
They suggest that we can very often not see what really is in front of us or not...