If you were like most children, you probably got upset when your mother called you by a sibling's name. How could she not know you? Did it mean she loved you less?

Probably not. According to the first research to tackle this topic head-on, misnaming the most familiar people in our life is a common cognitive glitch that has to do with how our memories classify and store familiar names.

The study, published online in April in the journal Memory and Cognition, found that the “wrong” name is not random but is invariably fished out from the same relationship pond: children, siblings, friends. It did not plumb the possibility of deep psychological significance to the mistake, says Duke University psychologist David C. Rubin, a co-author, “but it does tell us who's in and who's out of the group.”

The study also found that within that group, misnamings occurred where the names shared initial or internal sounds, like Jimmy and Joanie or John and Bob. Physical resemblance between people was not a factor. Nor was gender.

The researchers conducted five separate surveys of more than 1,700 people. Some of the surveys included only college students; others were done with a mixed-age population. Some asked subjects about incidents where someone close to them—family, friend or “other”—had called them by another person's name. The other surveys asked about times when subjects had themselves called someone close to them by the wrong name. All the surveys found that people mixed up names within relationship groups such as grandchildren, friends and siblings but hardly ever crossed these boundaries.

The mechanism behind the misnaming, says lead author Samantha Deffler, also a psychologist at Duke, is probably that related concepts “prime” one another. “If I mention a spoon,” she says, “I might activate a related concept, and you might be likely to think of a fork.” In the same way, she suggests, if Mom wants to call her daughter, the concept of daughter is also linked to her son. So she may call her daughter by her son's name.

In general, the study found that undergraduates were almost as likely as old people to make this mistake and men as likely as women. Older people and women made the mistake slightly more often, Deffler says, but that may be because grandparents have more grandchildren to mix up than parents have children. Also, mothers may call on their children more often than fathers, given traditional gender norms. There was no evidence that errors occurred more when the misnamer was frustrated, tired or angry.

The authors gleaned no data on the standard rom-com plot device of calling a lover by another's name. Possibly, the survey subjects may have identified such mistakes in the “friend” or “other” category—or not admitted it at all. Deffler does recall one young man who called his girlfriend by his sister's name. “Probably a bad sign,” she opines.

The biggest surprise to the researchers was that family members sometimes called one another by the family dog's name. With cats, such slipups did not happen—perhaps because cats do not generally respond as much to their names as dogs do, Deffler suggests, so people call them less often. This result, she says, affirms the special relationship people have with their dogs, which are truly thought of as members of their family.