So why is there such a fascination with rounded corners? I would venture that our attraction to rounded corners goes beyond the aesthetic and speaks to something more.
On one level, I think we’re attracted to things that appear to be organic in nature. Take the iPod for instance. While the industrial design of similar products clearly hints towards how the device came to be, Apple put a lot of effort into creating a device that feels more like it grew on a tree than assembled in a factory. They went to great pains to conceal the machine-like characteristics that would typically hold a device together (screws, etc.). The result is a smoother feel with very few edges or hard angles to be found. This “smoothness” not only speaks to usability but also fosters an emotional connection with the device. Some of our earliest memories are tied to objects and things that are far less than perfect and rife with right angles. Corners say “go away.” At the risk of sounding hoaky: smoother, rounder surfaces say “hold me.”
Beyond physical objects, there is also appeal to presenting information and the controls around information in a more organic context than just boxes and right angles. When we’re introduced with a complex set of information, especially a set that is unfamiliar to us, one of the first things we do is survey the information and apply context wherever we can. “This bundle of information is associated with that title. This group of buttons over there is clearly associated with that piece of information.” Etc.
As information architects and interaction designers, much of our work involves helping users make sense of the information and controls in front of them. In other words, we provide them with visual hints that guide them along the process of applying context to the interface in front of them. Rounded corners are a great way to do just that. Unlike plain old boxes with right angles, rounded corners clearly hint to what is inside ofand part of this cluster of information and what isn’t. When designers use solid colors it adds another level of reinforcement of context: the illusion of weight and volume.
Both explanations I’ve laid out above have one common denominator: they appear to leverage our own, very basic understanding of how we interact with and use objects in the physical world. The world is comprised of discrete objects that have their own integrity and are clearly separate from everything else (a beach ball, for example, is clearly its own thing not tied to anything else). Some objects even have controls on them that allow you to manipulate them. The knobs on your toaster, by virtue of being attached to your toaster, clearly control the toaster and not your refrigerator.
Rounded corners speak to and leverage this basic “expertise” we all possess and use to interact with the world around us. I’m pretty convinced that the appeal is beyond aesthetic. When used judiciously, we can create more intuitve experiences through such devices.
This article is based partly on a paper I wrote called Information Objects. For anyone who’s interested, It’s availabe in PDF format for download.
Update: A related article has recently been posted that explores the use of open space in visual design.