Color for the blind

Does only sighted people understand color? It is often thought that people born blind can learn facts about color—for example, that bananas are yellow—but cannot understand them as well as those with sight.

Now new research by Judy Kim and colleagues at Johns Hopkins University published in PNAS shows that this is not the case. In fact, the researchers found that blind people have a rich understanding of color developed through language alone.

Some of the results of the team's experiments seemed to align with the idea that color perception is acquired through sight. For example, blind people were less inclined to associate color data; when asked to name a common color for a banana, only 50% of sighted people said "yellow" compared to all sighted people. This seems to suggest that, at least in some cases, directly seeing the color of an object is more informative than acquiring the fact through other sources.

Overall, however, this study beautifully illustrates how people, both sighted and non-sighted, share a shared knowledge about color. Although the two groups differ in some areas, especially when it comes to associative knowledge about the color of objects, they are fundamentally similar in their understanding of the natural occurrence and application of colors. Blind people are able to understand in depth how colors work and make inferences about completely new objects based on their categorization. All in a way that closely resembles that of sighted people.

The authors believe that these data suggest that people who live in the same broader social culture, whether sighted or not, develop similar intuitive theories of color that can be applied to new situations. The source of this knowledge is almost certainly linguistic, and future research may determine at what age this color structuring develops in both sighted and nonsighted people.