Can A Toxic Mother-in-Law Actually Ruin Your Marriage? Experts Explain

Is your mother-in-law forming a wedge in your marriage? If you clash a lot with your mother-in-law, you're certainly not alone.

In a January 2022 study published in the Evolutionary Psychological Science journal, men and women in the U.S. "reported more conflict with mothers-in-law than with mothers, and mothers reported more conflict with their daughters-in-law than with their daughters."

In a study among hundreds of families over two decades conducted by Terri Apter, a psychologist and former senior tutor at Newnham College at Cambridge University, the results of which were published in her book What Do You Want From Me?, more than 60 percent of women said the relationship with their female in-law caused them long-term unhappiness and stress.

"Mother-in-law and daughter-in-law conflict often emerges from an expectation that each is criticizing or undermining the other, but this mutual unease may have less to do with actual attitudes and far more to do with persistent female norms that few of us manage to shake off completely," Apter told The Guardian in November 2008.

Why Are Relationships With Mothers-in-Law Difficult?

Elizabeth Fedrick, a licensed psychotherapist based in Phoenix, Arizona, told Newsweek that mothers are used to being the "cruise directors" for the family unit, often having an authoritative role, doing all the caretaking and decision-making.

This can potentially create "conflict and discord when another individual joins the family and has their own traditions and a separate family influence," Fedrick said.

Some mothers might become anxious or worried about losing time with their child and family dynamics changing when their child gets married, which can lead to the mother displaying "controlling, opinionated or inflexible behaviors" because of her fears.

Sometimes mothers might feel "they know best" and "assert their opinion in places where it does not belong," she said.

Mothers who do this might think they are helping or trying to protect their child or grandchildren, "however, this is often received as intrusive and offensive, and therefore is not helpful," Fedrick said.

What Role Should Your Mother-in-Law Play in Your Marriage?

"Mothers-in-law should certainly have a place in their child's life, even after they get married," Fedrick said. "They should even have a place in their child's marriage as a loving and encouraging support for their child and their child's spouse.

"However, a mother-in-law should not have a 'role' in their child's marriage in terms of being given authority or the ability to make or influence decisions about their child's family dynamics."

The relationship can become really difficult if the mother-in-law is "overbearing and oversteps their bounds, including giving input on child-rearing or household functioning," she said.

Jennifer Kelman, a family therapist for JustAnswer, a licensed clinical social worker (LCSW) and relationship expert, told Newsweek that mothers-in-law should be "taking a step back" and not involve themselves with issues within the marriage, because "when they do, things can become contentious very quickly."

A mother-in-law must accept that the relationship with their child has changed since they are married.

"That doesn't mean they still can't have a wonderful and connected relationship, but things do shift, and if the mother-in-law can accept that shift, then things can go smoothly," Kelman said.

She said conflicts with mothers-in-law might occur more often in families with diffuse boundaries: "It is hard to step back, but it is a must for the health of all relationships."

How Your Mother-in-Law Can Ruin Your Marriage

The overarching theme of the ways that a mother-in-law can ruin a marriage is the overstepping of boundaries. Kelman said: "They might not agree with things within their child's marriage and feel it is OK to voice their views."

This type of overstepping typically occurs when the couple has kids and the mother-in-law is perhaps around them too much, allowing her more opportunities to offer opinions and unsolicited advice, Kelman said.

Below are some more specific ways a mother-in-law can damage a marriage, according to Fedrick:

• Asserting unsolicited opinions about their child's relationship with their spouse, child-rearing tactics, financial decisions and more.

• Being critical or demeaning to their child's spouse, either through passive-aggressive or overt statements and behaviors.

• Being controlling or attempting to make decisions for their child's family.

• Saying negative things about their child's spouse to their child or attempting to negatively influence the way their child views their spouse.

• Creating unnecessary conflict and turmoil, as well as finding ways to make their child's spouse feel excluded or uncomfortable, including at family events, holidays or in general.

How to Manage Your Relationship With Your Mother-In-Law

Fedrick advised that "the first and foremost best way" to manage the relationship is by setting boundaries with your spouse around how much involvement the mother can have in your relationship.

This might include what topics you're OK with her sharing opinions on, how much time she can spend in your home, how often you're willing to visit her and the ways in which she's allowed to talk to you or your children.

"It is crucial for a couple to determine these things first within the safety of their own dynamic, and then explore and identify how this information will be communicated to each other's family, including mothers-in-law," Fedrick said. "This information must then be shared clearly and without room for interpretation with your mother-in-law."

Fedrick advised that the couple should consider asking the mother-in-law for help, support or guidance in ways that are appropriate and within your boundaries.

"Remember that you are not in competition with your mother-in-law and they ultimately can only give as much opinion or direction as you allow them to," she said.

Kelman believes one of the keys to managing the relationship is getting to know your mother-in-law for all of her "wonderful qualities and her less wonderful qualities."

It's worth understanding that while she can be difficult at times, her choices and behavior are "motivated by her love" for her kids and grandkids.

Although it might feel directed at you, her behavior is "often due to her own feelings of loss or insecurities within the relationship."

Relationships are about "give and take," Fedrick said, so it is beneficial to nurture your relationship with your mother-in-law and to be intentional in helping her feel included and valued.

How to Prevent Issues With Your Mother-In-Law

"It is not enough to just set boundaries, there also must be the willingness to hold boundaries," Fedrick said.

If your mother-in-law "asserts their opinion on something out of bounds, or engages in a clearly defined disrespectful manner," it is crucial to ensure your mother-in-law is aware of this and to remind them that you're not OK with that behavior, she advised.

If this behavior resumes, you and your partner will need to identify what the next step should be. This might include spending less time with your mother-in-law, removing yourself from situations that you're not comfortable with and reducing the amount of information you share with her, she said.

Kelman said if boundaries are maintained and the mother-in-law "stays in her lane," things can go quite well.

"Leave the jealousy and competition out of things as that just causes strife within the marriage and while on the surface that might not be the intent, but underneath a little gain may be enjoyed," she said.

Don't make it about taking sides and "more about how people feel and what they need," Kelman said.

Fedrick said it's helpful to remember that "you have no control over your mother-in-law or her behaviors, but you do have control over removing yourself from uncomfortable or disrespectful situations."

Do you have issues with your mother-in-law? Let us know via life@newsweek.com. We can ask experts for advice, and your story could be featured on Newsweek.