Dog lovers: could there be a better month than August to salute our canine companions? After all, August 10 is the day poor Rin Tin Tin died, and it’s the day Snoopy celebrates his birthday, in a 1968 Peanuts strip. Two weeks later, on August 26, it’s National Dog Day, according to the Animal Miracle Foundation & Network. To celebrate the dog days of summer, we’ve unleashed Jeopardy!’s Ken Jennings, who will correct some of man’s worst misconceptions about man’s best friend.
The Debunker: Can Dogs See Colors?
Fans of the children’s book hero Encyclopedia Brown may remember the 1966 classic “Case of the Boy Bullfighter,” in which we learn that young Miguel Sebastian must have lied about his dog being able to see the color red—because dogs are color blind! A humiliated Miguel returns his ill-gotten loot, a stolen tooth collection, and has his mom repair the seat of Charlie’s red pants. A happy ending!
I would never besmirch the reputation of Idaville’s number one crimefighter, but this landmark case may have given you the idea that dogs don’t see in color at all. In fact, it was long believed that this was true: dogs saw the world in shades of gray, and used brightness levels rather than color to identify things. But that’s not true: it’s been known since at least the 1990s that dogs can see color, and a 2013 study from Moscow proved that they can use it to navigate their environments. The Russian scientists locked food bowls in boxes of different colors but identical brightness levels. All the dogs were able to distinguish the correct box 70 percent of the time—and most could do it with 90 to 100 percent efficiency.
But that doesn’t mean that dogs aren’t color blind—in a way. Let’s back up. Humans can see a full spectrum of color because we have three types of cone cells in our retina, each most sensitive to a different wavelength of light. Dogs, however, have only two types of cones. They can distinguish blue and yellow, but not red and green. This is pretty much the same spectrum visible to humans with deuteranopia, the most common form of color-blindness. In other words, you can trust your seeing-eye dog to see some colors, but maybe have someone double-check his work on traffic lights.
Quick Quiz: What TV comic often insists, “I don’t see color. I don’t see myself as white. People tell me I’m white”?
Ken Jennings is the author of six books, most recently his Junior Genius Guides, Because I Said So!, and Maphead. He's also the proud owner of an underwhelming Bag o' Crap. Follow him at ken-jennings.com or on Twitter as @KenJennings.