05/09/2014 12:06 pm ET Updated Jul 09, 2014

What Do You Call Your Mother in Law?

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A bride's stress does not always end after the wedding, it turns out. For many women, figuring out what to call their new mother-in-law is just as nerve wrecking as picking a wedding caterer or mapping out seating charts.

For Mona Shand, addressing her mother-in-law was a source of great stress when she was a newlywed. "For years, I just tried to avoid having to call her anything aside from 'you,'" Ms. Shand, who got married in 2003, said.

Even though she always had a strong relationship with her mother-in-law, Ms. Shand couldn't bring herself to call her "mom." "In my mind, that is a title reserved for one person and one person only," she said. Calling her by her first name, or a more formal "Mrs." also didn't sound right to Ms. Shand.

Same with Patricia Quinn, who has been married for over 30 years and would rather skip a dish than directly address her mother-in-law by a name. "If I couldn't catch her eye to get her attention, then I would have to ask someone else to pass me the potato salad," said Ms. Quinn. "Or I would do without it. It really is crazy, but that's the way it is," she said.

When she was dating her now-husband, she called his mother "Mrs. Quinn," but once they were married, that no longer sounded right to her. Calling her by her first name seemed too informal, and calling her "mom" was out of the question. "That option seemed weird because she's not my mom," Ms. Quinn said.

The confusion over what to call one's mother-in-law does not surprise Deborah Tannen, a professor of linguistics at Georgetown University and author of You Just Don't Understand: Women and Men in Conversation.

"In so many ways, our American culture is less stratified than others, but this means less is prescribed, and more is up for grabs," Ms. Tannen said. "In other cultures, you'd know exactly what you have to call them, and you're home free," she said.

In Brazil, for instance, it's a given that you call your mother-in-law by her first name. In Egypt, a daughter-in-law would call her spouse's mother "Tante," which means aunt, and is the convention for addressing elders in your social circle.

But in the U.S. there seems to be as much variety in what to call your mother-in-law as there are marriages. Almost two-dozen women were interviewed for this story, and their responses were all over the map, with no common thread connecting women of similar ages, or women who got married in the same decade.

Some women call their mother-in-law "mom" because they feel very close to her, while others say that despite loving their mother-in-law very much, they couldn't possibly use that term for anyone other than their biological mother. Other women use "mom" for their mother-in-law because their own biological mother has passed away, but some would never call her in-law "mom" precisely because her own mother has died, and taking up a new "mom" seems disrespectful.

While some women feel that calling a mother-in-law by her first name is too informal, others feel it's too formal. Some daughters-in-law make up their own term: One woman goes with "Mama Schaefer," while another simply calls her "MIL." One woman said she addresses her mother-in-law as "mom" in writing, but in person, she always uses her first name.

And of course, there are those who, like Ms. Shand and Ms. Quinn, can't find any term that sounds right, so they avoid calling their mothers-in-law anything at all.

"I have been a daughter-in-law for nine years now, and I have always struggled with what to call my mother-in-law," said Teresa Watkins. "My solution is that when I speak to her, I do not address her with any title at all. I just skip it all together," she said.

The source of the confusion may be rooted in the gradual in-formalization of social interactions in the U.S. "It's a post World War II phenomenon, maybe even more recent," said social historian Joan Brumberg, a professor emerita of history, human development and gender studies at Cornell University. The idea that you can choose what to call an elder goes hand in hand with the modern concept of individuality, Ms. Brumberg said.

But cultural changes are slow and organic and have left a lot of people confused. "There doesn't seem to be a rule about it anymore," Ms. Brumberg said.

In Ms. Brumberg's own family, her parents called their mothers-in-law "mama." Ms. Brumberg's daughter-in-law calls her Joan, which she likes. As for her own mother-in-law, Ms. Brumberg said, "I certainly would never have called her by her first name. Occasionally I would say 'mom,' but usually I avoided calling her anything."

This diversity in nomenclature is an interesting marker of social change in families, and it probably happens in different ethnic groups and social classes in different rates, Ms. Brumberg said.

Knowing what to call your mother-in-law may be easier in families and communities that still have a strong naming tradition. Faith McKinney had no trouble knowing that she would call her mother-in-law "Ms. Dorothy." "In the African American community it is considered disrespectful to call your elders by their first name, so we always add Mr. or Ms. when we address them," Ms. McKinney said.

For everyone else, the common element that seems to save a lot of daughters-in-law from their confusion is having children. "Now that I have a daughter who calls my mother-in-law "grandma," I do the same," Ms. Shand said.