The tendency of the brain to group objects, known as the principle of proximity, is achieved by placing shapes, forms or other elements close to one another in a work of art, so that the objects are perceived as a unified whole. The principle can be further broken into the concepts of close-edge space, touch, overlap, and combination through external elements.
Proximity is one of four grouping concepts united under the German-born gestalt theory, developed in the 1920s. It is closely related to the principle of similarity, which states that the more alike objects are, in terms of size, color, value or shape, the more likely they are to form groups. However, when the two principles are used together, proximity relationships always maintain dominance.
By properly applying one or more of the gestalt theory's grouping concepts, meaning is enhanced, as the eye is drawn down the artist's intended path and not diverted by clutter or busyness. In other words, gestalt principles are all about perception, according to Smashing Magazine, a resource for design professionals. The magazine states that the principles of the gestalt theory speak to the core of the visual language within which a person works. It encompasses the overarching ideas of emergence, in which the whole is perceived before the parts; reification, which is the tendency of the mind to fill in gaps; multi-stability, the mind's need to avoid uncertainty; and invariance, which is the ability to recognize similarities and differences from many perspectives. All of these ideas converge in the principle of proximity.