When you see blue, is it the same blue that I see? Such questions have bedevilled philosophers for centuries. Ultimately, we cannot know how any one person really perceives or understands color. But researchers have studied—and debated—how the human eye processes light, how global cultures talk about color, and even how infants divide up the rainbow.
Here are three arguments suggesting color perception is a universal experience, and three that it is not.
The basics of color perception are shared by all
Human eyes are all wired the same way (most of the time)
The vast majority of us have three types of light receptors in our eyes, called cones, that are optimized to detect different colors or wavelengths of light. While our vision is complicated, generally speaking, these cones are optimized to see red, green and blue light; the brain combines this information to perceive color. With these three cones, most people can distinguish millions of distinct shades.
There are a few exceptions, of course. There are a variety of types of color blindness, usually affecting men, where one or more of these cones is missing or mutated, often making it hard to tell green from red. On the Pacific island of Pingelap, a shocking 10% of people are completely color blind. On the other hand, some women have an extra type of cone, giving them ‘super’ color vision. These exceptions aside, the vast majority of humans have the same basic perceptual abilities.
Cultures around the world share a concept of basic colors
One way of assessing what people really “see” (what their brains interpret from their eyes) is to look at their language. In the early 1970s, researchers used a network of linguist-missionaries around the world to gather data on 110 unwritten languages: The missionaries showed more than 300 color chips to tribal peoples in an attempt to learn the smallest set of simple words with which the speakers could label any color. The resulting World Color Survey found that, on the whole, people tended to categorize colors into the same basic groupings, though some languages had fewer basic colors than others. The most sophisticated color languages, including English, each had a grand total of 11 basic color terms.
Babies distinguish between basic colors
Babies, even before they can talk, seem to think there’s more of a difference between, say, what we call green and blue, than between two different types of blue, even if these colors are all the same ‘distance’ away from each other on a color chart. A study of 4-month-olds showed that they were quicker to notice a green circle against a blue background than a different-blue circle against that same blue background. The work has been repeated in 8-month-olds. This hints that color categorization might be hard-wired into the brain.
Color means different things to different peoples
Some cultures don’t talk about color
Many cultures see and talk about color very differently from the Western world. For instance, the Candoshi of Peru, like a handful of other societies, don’t have a word for the over-arching concept of ‘color’. Some researchers argue that the Candoshi also don’t have specific color words, but rather describe things more holistically. In one study, if the Candoshi were shown a red chip on a ceramic surface, they usually described it with a word that means “like ripe fruit.” But if the same chip was on the floor, people more often deemed it to be “like blood.” Perhaps these words aren’t really color terms at all. Likewise, a linguist has argued that the Warlpiri people of Australia have no color talk. Many argue that people in pre-manufacturing societies simply don’t find color so important; while different colors might be the only thing that distinguishes one shirt from another, that rarely if ever happens in the natural world.
Different cultures group colors differently
Show someone a rainbow and ask them to put lines where they see a division between distinct colors; chances are everyone will do it differently. Most people from a given culture tend to be similar in their distinctions, perhaps making more groupings in the blue region, or in the red. But cultures differ from each other. Sometimes the groupings are completely foreign to what Westerners might expect. For instance, when the Jahai of the Malay Peninsula were asked to group color chips, they divided them up conceptually: red and blue went together, for example, because “husband and wife go together,” they explained.
Color language evolves over time
Even the way the Western world sees and talks about color has changed over time. The ancient Greeks believed there to be something special about the number seven, for everything from musical notes to colors. A word for orange did not exist in English until the 1500s, when orange trees were brought to Europe from Asia. In the 1600s, Sir Isaac Newton continued the tradition of sevens, listing the rainbow as the now-traditional red, orange, yellow, green, blue, indigo, and violet.
Bottom line: In the end, whether you see color as a universal experience has something to do with how you define a “universal experience,” as well as how you interpret language. What does your world view lead you to see: Is color perception something we all share, or something that makes us different?
An original version of this article appeared in SAPIENS, a publication that aims to transform how the public understands anthropology. The content has been adapted by the author to fit The Perspective’s Big Debate format.