There may be some truth to the belief that tortoiseshell cats have a little bit of an attitude—or tortitude, as it’s called. A new study published in the Journal of Applied Animal Welfare Science from researchers at the University of California, Davis suggests that torties, calicos, and other multicolored cats are a tad more aggressive than cats of other colors.

The color of a cat’s fur is inherited. The genes responsible for orange and black fur color in cats are carried on the X chromosome, which is why calico and other multicolored cats are typically female (as are fully orange cats). Each color is carried on a different X chromosome, so the animal needs two of them. That's why male calicos only exist as the result of a genetic mutation that leaves them with an XXY genotype.

Some behavioral traits can be inherited, too. For instance, Siamese cats are more likely to compulsively suck wool. Other traits, like shyness, are believed to develop after birth as a response to the cat’s environment. This study looked into whether the two might be linked.

The online survey asked more than 1400 cat owners—recruited through cat-centric Yahoo listservs and a UC Davis veterinary school Facebook page—about their cats' behavior, including whether they were aggressive toward humans during everyday interactions, while being handled, or at the vet. The final sample included 657 male cats and 617 female cats, largely living in North America.

The researchers found that multicolored female cats—tortoiseshell, calico, and tortoiseshell tabbies—were more aggressive toward people than cats of other colors. Unexpectedly, grey-and-white cats were, too.

This is not the first study to associate coat color with certain behaviors or other genetic traits. Color has previously been linked to aggression in cocker spaniels, and to behavioral traits like excitability in Labradors. Cats’ white coats have been linked to congenital deafness.

This study wasn’t done with a random sample of cat owners, so it’s far from definitive, but it lends credence to the idea that behavior and color can be linked. “These findings support some common assumptions about personalities associated with different cat color patterns and help current cat guardians better understand their companion cats,” the researchers write.

Still, the results weren't dramatic enough to suggest you should never get a calico cat. The “differences are relatively minor,” they conclude, but knowing this slight tendency might help owners and vets better prepare for the type of behaviors they might observe. 

[h/t USA Today]