When the great architect Philip Johnson first visited the Guggenheim Museum in Bilbao, designed by Frank Gehry, he started to cry. "Architecture is not about words. It's about tears," Johnson reportedly said. Something about the museum's majestic curves moved him at an emotional level. Many others must get a similar feeling, because the building is usually ranked among the most important in modern times.
Whether or not Johnson and Gehry realized it, the Bilbao and its swirling façade tapped into a primal human emotional network. Time and again, when people are asked to choose between an object that's linear and one that's curved, they prefer the latter. That goes for watches with circular faces, letters rendered in a curly font, couches with smooth cushions—even dental floss with round packaging.
Recently neuroscientists have shown that this affection for curves isn't just a matter of personal taste; it's hard-wired into the brain. Working in tandem with designers in Europe, a research team led by psychologist Oshin Vartanian of the University of Toronto at Scarborough compiled 200 images of interior architecture. Some of the rooms had a round style like this:
Others had a rectilinear form, like this:
Vartanian and collaborators slid people into a brain imaging machine, showed them these pictures, and asked them to label each room as "beautiful" or "not beautiful." In a study published earlier this year, they reported that test participants were far more likely to consider a room beautiful when it was flush with curves rather than full of straight lines. Oblong couches, oval rugs, looping floor patterns—these features got our aesthetic engines going.
It's worth noting this isn't a men-love-curves thing; twice as many women as men took part in the study. Roundness seems to be a universal human pleasure.
Beauty ratings were just the first step in the study. The researchers also captured the brain activity that occurred when the study participants in the imaging machine considered the pictures. Turns out people looking at curved design had significantly more activity in a brain area called the anterior cingulate cortex, compared to people who were looking at linear decorations. The ACC has many cognitive functions, but one is especially noteworthy in the context of Vartanian's study: its involvement in emotion.
So curved design uses our brains to tug at our hearts. Some of us cry outside great buildings as a result. Some of us reach for another brand of dental floss. Some of us, beyond all rational judgment, type in Comic Sans font. "Our preference for curves can not be explained entirely in terms of a 'cold' cognitive assessment of the qualities of curved objects," Vartanian tells Co.Design. "Curvature appears to affect our feelings, which in turn could drive our preference."
The Bilbao-sized question is why exactly curves give us a visceral pleasure. Some neuroscientists believe the answer may have adaptive roots.
Another brain imaging study, conducted several years ago by Moshe Bar of Harvard Medical School, found that viewing objects with sharp elements—once again, square watches, pointy couches, and the like—activated the amygdala. That's the part of the brain that processes fear. Bar and collaborator Maital Neta proposed that since sharp objects have long signaled physical danger, human brains now associate sharp lines with a threat. Curves, meanwhile, may be seen as harmless by comparison.
"In other words," says Vartanian, "we prefer curves because they signal lack of threat, i.e. safety."
There's a nice clarity to that explanation, but it certainly has some limitations. The most basic of these is that some sharp lines feel warm and welcoming (see: the New York City skyline, or Ikea furniture) and some curves are plenty scary (see: a rattlesnake, or Nicki Minaj). Not every straight-versus-curve contest is as clear as knife versus spoon. Culture, context, and familiarity can all influence our perception of contour.
It's also critical to point out that just because people have a natural neural affinity for curves doesn't mean round design is always superior. If researchers asked people to rate architecture based on functionality instead of beauty, for instance, they might get different results. (In fact, Vartanian says he's studying that question next.) The Bilbao in all its sinuous glory may bring tears to the eye, but it probably took a very rectangular truck to bring construction material to the Bilbao.