Interior designer Arjan Nijen Twilhaar says "we all know that beauty is in the eye of the beholder, however, what is considered beautiful can simply be broken down into balance, proportion, and symmetry." Whether you buy into the idea that a properly arranged room can make you feel happier or intellectually engaged or not, multiple studies have shown that these are just a few possible effects symmetry has on our psyche. If you understand how we see rooms and how our brain digests the information, you can then apply some simple principles to your interiors.