It’s tempting to wonder in such cases if the parents aren’t being a little too self-serving in their blame of the spouse. Maybe the parents are far more possessive than they’re admitting. Maybe they wouldn’t like anyone their adult child brought home. Maybe they’re a lot more critical than they’re aware of or comfortable acknowledging.

While those cases exist, I’ve also worked with enough families to know an adult child’s marriage may disrupt once-close family relationships. For example, in my survey of 1632 estranged parents conducted through the University of Wisconsin Survey Centre, I found 70% of parents didn’t become estranged from their adult child until after their child married.

While that figure seems high, it’s not entirely surprising: Each family has its unique history, traumas and identities that may either mesh or conflict with the other. Bringing two families together in marriage is like bringing together two cultures, even if they’re similar in religion, ethnicity or socioeconomic class.

Why a daughter-in-law could lead to disruption

While there’s plenty of variation, daughters and daughters-in-law are more likely to determine how much time is spent with whom. This matrilineal advantage can be an asset if the daughter-in-law likes her in-laws and wants to make sure her husband’s parents get equal time with them and the grandchildren, as many do. However, it can become a force of division if she does not.

In situations where the wife does not get along with her in-laws, the husband is much more likely to engage in what I call “performative masculinity,” a visible demonstration of aggressive and protective behaviour for the theatre of his wife. In such cases, it’s not unusual for relatively small mistakes or insensitivities on the part of the parents – behaviours that a healthier person would consider annoying but forgivable – to be labelled as enormous betrayals that must be strongly prosecuted.

There are a variety of reasons sons may be more vulnerable to being manipulated in this way than daughters. For most men, their wives are their best friends, if not their only friends. Therefore, these men may pay a higher price if they push back against the wishes of their wives.

As journalist Ruth Whippman observed in her book, BoyMom: Reimagining Boyhood in the Age of Impossible Masculinity, parents don’t talk to boys as much about their feelings when they’re raising them. I’ve observed that partly as a result, they may be less able to advocate for themselves or their families of origin if there’s conflict with their wives.

The fragile nature of male identity also means that most men are only one shameful comment away from feeling emasculated. Therefore, if his wife says, “You need to stand up for me around your parents. You’re such a mama’s boy. You let them walk all over me and don’t say anything,” many men would be unable to resist the implications. They would feel compelled to strongly demonstrate her accusation of weakness is without merit.

Why a son-in-law could lead to conflict

There is no shortage of troubled, narcissistic sons-in-law who also engage in restricting or ending their spouse’s relationships with friends and families; men who use fear, threats or psychological manipulation to make their wives too scared or guilt-ridden to defy their husbands’ wishes.

In those situations, parents and other family members learn the hard way that criticising the son-in-law only strengthens his willingness and commitment to limit her contact. Because of his insecurity or narcissism, he views anyone – especially his wife’s loving family members – as threats that have to be eliminated.

These dynamics are not limited to heterosexual couples but can exist in any romantic relationship where a partner is manipulative and the family is unable to combat their influence.

But often, there are ways parents can avoid, or at least limit, the conflicts an in-law creates.

Strategies to reduce conflict

As always, start with your own behaviour

Even when we think we’re behaving in the most upstanding, reasonable and sympathetic way, we may be blind to how we have pushed our child further into the arms of their spouse. We may also have been insensitive to an overly sensitive person; so what looks innocuous on our end may not have been experienced that way by your adult child’s spouse.

Do not complain about or criticise the spouse

It will get passed on, and your life will be made worse for it. It will also strengthen the spouse’s ability to say that you can’t be trusted and that distance or estrangement is the best thing for their mental health and that of their children.

The audience is not only your adult child but also their spouse

Making amends with the child’s spouse strengthens your child’s ability to tell their husband or wife that you are trying and should be given a chance at reconciliation. It’s also a good way to see if your daughter-in-law or son-in-law is open to reestablishing contact, however hopeless the situation may seem. If your child or their spouse claims you haven’t apologised enough, consider apologising again. It is hard to make amends to someone who is manipulating your child, and it may not persuade their spouse to open the door to you. But it will show your son or daughter that you’re turning over every stone to make things work.

Respect their limits in your role as a grandparent, even if you don’t like the limits

They get to decide how to raise their children and how much time you get with them.

Remember that your child’s spouse is now the gatekeeper to any relationship you might have with your child or grandchildren. You might not like whom they married, and they might not be that crazy about you. But failing to handle these dynamics with care only brings more conflict, distance and pain. It limits the possibility of seeing your child and grandchildren again. And it makes a potentially resolvable situation impossible to resolve.

Joshua Coleman, PhD, is a clinical psychologist in the Bay Area and senior fellow with the Council on Contemporary Families. His newest book is “Rules of Estrangement: Why Adult Children Cut Ties and How to Heal the Conflict.”