It happens to the best of us: You mean to call your kid from the next room, but for some reason call out your dog’s name instead. According to cognitive scientist Samantha Deffler, mixing up names is “a normal cognitive glitch,” and actually has nothing to do with having a bad memory or aging. Instead, Deffler says that our brain organizes names into special folders, and the names we scramble are likely to belong to the same category (i.e. friends, family, colleagues, etc).

“Like in the classic scene from the TV show, Friends. When Ross says his wedding vows, he is asked to repeat his fiancée’s name, Emily. He says his former girlfriend’s name Rachel instead. Now Ross probably had both Rachel’s and Emily’s names in his mental folder of loved ones and a mental mix-up ensued,” NPR’s Michelle Trudeau writes. Deffler and her colleagues studied the phenomenon, known as “misnaming,” by asking more than 1,700 participants about their personal experience with either misnaming or being misnamed, and found that misnaming is a common phenomenon and is most likely to occur with “semantically similar” (i.e. individuals within the same category) names.

Also, if this doesn’t settle the dog vs. cat dispute, we don’t know what will: Deffler et al. found that the inclusion of a pet’s name in a misnaming incident is significantly more likely to occur with a dog’s name than with a cat’s, suggesting that “dogs may be a central part of (at least some) families … as human-like members, whereas cats and other pets, although they may be part of the family, are not categorized as ‘human-like.’”