For felines as well as humans, life isn't always fair.

A new survey suggests that cats are judged by the color of their fur just as people are sometimes judged by the color of their skin, with cat fanciers more likely to assign positive personality traits to orange cats than to kitties of other colors.

The survey, led by a doctoral student at the University of California at Berkeley, showed that orange cats are often seen as friendly, whereas white cats tend to be seen as aloof and tortoiseshell cats as intolerant or having "too much attitude."

What about black cats? The survey showed that they're less likely to be adopted than cats of other colors--a big deal, since approximately 21 percent of the 86.4 million pet cats in the U.S. were adopted from shelters, according to the Humane Society of the U.S. What's more, black and other dark-colored cats are more likely to be euthanized.

Are cat fanciers showing a keen sensitivity to cat personalities--or are the tabbies victims of intolerance?

"To date there is little evidence that these perceived differences between differently colored cats actually exist," the student, Mikel Delgado, said in a written statement released by the university. "But there are serious repercussions for cats if people believe that some cat colors are friendlier than others."

For the survey, Delgado and her co-authors asked 189 cat owners and cat lovers to rate the personalities of black, white, bi-colored, tri-colored (tortoiseshell or calico) and orange cats. The survey was published online in the journal Anthrozoos.

No matter what their color, all domestic cats are members of the species Felis catus. They have a long history as pets, having first been domesticated by ancient Egyptians as long as 4,000 years ago, and are now the world's most popular pet.

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