Why Humans Are Obsessed With Circles, According To Science

It’s been the go-to form for designers and artists for millennia. A new book draws on history, biology, and psychology to explain why.

From the sun, moon, and planets, to the eyes that give us sight, the circle is everywhere in the natural world. But it’s also stamped everywhere in the human-made world: From wheels and domes to logos and infographics. It’s a form that is utterly pervasive.


[Image: courtesy Princeton Architectural Press]
In a new book called The Book of Circles, the data designer Manuel Lima looks to history and evolutionary science to explain why people like circles so much, using his research to create a taxonomy of approximately 300 images of circles that date from thousands of years ago up to the present day.

While hardly comprehensive, the images themselves form a compelling argument about just how ingrained the circle is in the human mind–and Lima gives some compelling explanations for it.

A 40,000-Year-Old Fixation

The Book of Circles is Lima’s third book–he’s also written about the history of tree diagrams and the representation of networked information–making it the result of 10 years of research into the visual metaphors that humans have used to express information over millennia. He believes that for contemporary data designers, having a historical grounding in the history of the circle is a necessary component in situating one’s work in time.

Lima explains that the first circular inscriptions have been dated to about 40,000 years ago, when ancient humans carved circular marks called petroglyphs into rock. “It’s not clear what they were trying to achieve with them, but some of the oldest ones are concentric circles, spirals, and the wheel,” he says. “You see that in different areas of the globe, in different areas of time. You can see there’s some sort of fascination.”

Ten thousand years ago, he says, the circle infiltrated every area of human knowledge, from architecture and urban planning to linguistics and objects. Today, it remains a dominant form in the world of information design. But that still doesn’t explain its omnipresence. For that, Lima points to several scientific theories about humans’ predilection for circles.

3 Theories From Science

We know that humans are more attracted to curvilinear shapes than angular shapes, something backed by several recent studies. Lima believes this makes sense from an evolutionary perspective: “It goes back to primitive roots in nature, where most shapes are curvilinear,” he says. “They’re softer, they provide some safety, as opposed to angular shapes–the teeth of an animal, the hard shape of a rock. Those are signifiers of danger.”


Another theory is that humans associate geometric shapes with emotions–and that circles correspond with happiness. The psychologist John N. Bassili conducted an experiment in 1978 in which he painted the faces of participants black, and then added luminescent dots. When the participants were asked to perform expressions of happiness, the dots would form into curvilinear, upward, open shapes, while expressions of anger created downward, angular forms, with the angry face shape activating the amygdala’s sense of fear. The circle, in the context of his research, is an abstract symbol for happiness, while the pointed triangle represents anger.

Lima’s last theory has to do with the curved shape of the human eye, which slightly distorts the world at the edges of vision–similar to the distortions in a crystal ball or a fish-eye lens, though not quite so exaggerated. Circular shapes tend to complement this physical construction of the eye. “[Circles] fit so well into that visual apparatus,” he says.

In the book, armed with his theories, Lima proceeds to sort through hundreds of images of circles, making his argument about its historical presence by example. These history lessons are most interesting when they juxtapose circular images from utterly different eras, places, and contexts; in one instance, an image of the 18th-century dome of the Basilica of Superga in Turin, Italy, is placed side by side with a photograph of the Compact Muon Solenoid, a scientific instrument that detects the particles participating in high-speed proton collisions at the Large Hadron Collider in Cessy, France. In another, a pieced-together image of Jupiter’s north pole, taken by a NASA spacecraft in 2000, sits next to an interactive project that uses a circle to show trends in the New York Times‘s coverage over 30 years, and a visualization of the language used in Sufjan Stevens’s song “The Predatory Wasp of the Palisades Is Out to Get Us!”

Ultimately, the book acts as a corrective to designers’ tendency to view themselves on the cutting edge of everything.

“This is an attempt to show that data visualization is a much longer and older discipline than people give it credit for,” Lima says. “There’s a tendency to think of it as a new discipline rising to meet the demands of the 21st century. This is why we need to look deep into history.”

About the author

Katharine Schwab is a contributing writer at Co.Design based in New York who covers technology, design, and culture.