Giants and Dwarfs in the Room of Ames

If in your life you have been curious about psychology and, perhaps, you have bought a book on general psychology, most likely there was at least one section dedicated to optical illusions. But why should Psychology be concerned with optical illusions? I'll try to give an answer.

When I defined psychology, I did so as the science that studies behavior, and when I talked about behavior, we saw how it is linked to the environment. So it's important to know how we perceive the environment. Optical illusions demonstrate that we don't always represent the environment that surrounds us correctly.

The mind reconstructs what the eye gathers from incoming stimuli, but why do some of these reconstructions fail? Why, in a room where two people are approximately the same distance away, does the mind tell us that one is exaggeratedly large and the other is exaggeratedly small?

First of all, the room is observed through a peephole and the base of the room is not rectangular (as it appears in the image), but a trapezoid. The two people are not actually at the same distance, but one is close (the one that looks very large) and one is far away (the one that looks very small). Now imagine being 30,000 years ago. How useful can a visual system be that can recognize the correctness of dimensions while looking through a peephole? Not very much, right?

Let's go back to the concepts related to evolutionary theory. 30,000 years ago, when hunting, people looked from heights or prairies. The visual system developed when the environment provided many details. It's normal that if we "tease" the visual system with tests it's not suited for, it may fail. Studying optical illusions means studying the regularities that our brain is evolutionarily prepared to recognize.

The analysis of optical illusions such as the Ames room, the Kanizsa triangle, or the barber pole has provided important data to those who have studied the perceptual system in more detail. For example, through neuroscience, we are now able to provide more precise reconstructions of the path that information takes from the eye to the brain, and on this, psychological studies on optical illusions have been very helpful.

What optical illusions do you know? Do you think it's strange that psychology has dealt with this?

If you want me to describe in my own words a topic of psychology, please request it in the comment section.

Cited sources: Holway e Boring (1941) - Determinants of apparent visual size with distance variant. Additionally, you can read about the workings of the Ames room on Wikipedia.