Preparing to go home for the holidays can feel like readying yourself for battle. You steel yourself for the barrage, knowing your decisions will be questioned (“Another glass of wine?”) and your personal life pried into (“When are you and Gena going to give us a grandchild?”). No matter how much or how little of grandma’s food you eat, it will be the incorrect amount. So, in order to gird you for the impending season, MR PORTER learnt about the most fraught relationship dynamics from experts on human psychology, from a diplomat to a hostage negotiator to Ms Kim Kardashian West, and discovered the secrets of surviving the festive season. Be safe out there.

The expert: Mr Dennis Ross, co-author of Be Strong And Of Good Courage, diplomat to Israel and Palestine for Presidents George HW Bush and Bill Clinton, special assistant to President Barack Obama

In addition to brokering international treaties, ambassador Mr Dennis Ross is experienced at finessing mother-in-law dynamics. During an unplanned diplomatic trip with secretary of state Mr Jim Baker, Mr Ross announced to the secretary that had to leave. He and his wife were flying to visit his mother and there was, he explained, “No possibility of me staying here and having my wife go there and be with my mother. I can’t make peace in the Middle East if there isn’t peace in my household.”

Mr Ross explains that in any negotiation or mediation, the key is understanding what motivates the other party. When your mother-in-law is critical, she is subtly reminding her daughter/son-in-law that nothing – or at least nothing they can do – is good enough for her child. If you or your partner push back, it creates a lose-lose situation. The way around this is counter-intuitive. You must acknowledge the validity of her disparagement. When she says she can’t believe your wife is stepping away from family time to, for example, fulfil a work commitment, your partner can respond, “I really appreciate that point of view. I understand that you might see it differently, and I understand that’s the way things are done here.” Because your mother is coming from a place of insecurity – this person, a clearly inferior creature, has “taken” her son – acknowledging her point of view lets her know she’s being taken seriously. However, “Acknowledgment isn’t acceptance,” says Mr Ross. So, once she’s had the validity of her feedback recognised, your partner can calmly explain why she needs to finish that brief on Christmas Eve.

The Expert: Ms Stella Reid, star of Nanny 911 and co-author of The Nanny Chronicles Of Hollywood

Like a child notorious for getting wild at parties, a family member who has a history of going overboard with alcohol is a known quantity. While that doesn’t make dealing with them easier, it does mean you can mitigate the problem before it begins or, as nanny Ms Stella Reid says, focus on “prevention, rather than cure”. Think of yourself as a babysitter and plan accordingly. Setting a toddler up to succeed might mean sticking as closely as possible to their normal schedule and having them nap on a long car journey. Likewise, encourage a tippler to drink water and snack before the huge 3.00pm meal, rather than fast. Try to be sensitive to the fact that your cousin might be drinking to cope with anxiety. “If they don’t know how to manage their feelings or regulate their frustration,” Ms Reid says of everyday life, “why would you think that it would be magically OK in a family setting with 30 people around Thanksgiving dinner?” Engaging with them to help them feel more comfortable can head off the emotions they’re chugging to avoid.

If things do spiral, Ms Reid recommends using distraction to diffuse the situation. “If it was a toddler you were playing with and they wanted one toy and another child had it, you’d say, ‘Oh, here, let’s play with the fire engine.’ Those tactics can be used in situations with adults as much as they can with children.” Ms Reid says this can be as simple as luring your relative into another room, ideally one away from the bar.

The expert: Mr Daniel Van Kirk, comedian, star of comedy album Thanks Diane

Perhaps it’s the chilly winter air or too much smoke inhalation from all the crackling fires, but something about the holidays really emboldens the sexists in our lives. Comedian Mr Daniel Van Kirk recommends using humour to combat any wayward misogyny. So if Uncle Bob says to your spouse or your sister, “You think you don’t want kids, but one day your baby switch is gonna flip and you won’t be able to help it,” Mr Van Kirk recommends responding with something such as, “Tell everyone more about the mentality and life of a woman. But first, what’s the switch called when someone can’t avoid making sexist comments? Or can you not help it?” It works, Mr Van Kirk says, because “it’s hard to be angry or argue while you’re laughing”. And if you’re not upset, you might hear what someone is saying and think about why you believe what you do.

Mr Van Kirk has employed this tactic professionally to combat hecklers, but recently realised its value in family gatherings when a relative expressed scepticism about the Black Lives Matter movement, which organised protests about the murders of black people by American police officers. Mr Van Kirk says he told his family member, “OK, let’s walk that out a little bit. You’re saying that on a Tuesday in August, the African-American community in every major city decided, together, through some sort of back channel Underground Railroad of information, that they didn’t like cops any more. And they were so committed to this that they said, ‘Let’s take off work and march, and get thousands of people to all say they feel the same way in Oakland, in Houston, in Chicago, in St Louis, in Baltimore, in Detroit, in New York. And we’re all going to do it just for fun.’ Meanwhile, we have a family of 14 people and we can’t decide what type of pizza we want in less than two hours. But everybody else in this Black Lives Matter thing is just making it up in the most efficient way possible. And my family member was like, ‘All right. Yeah. That kinda makes sense.’”

Thanks Diane by Mr Daniel Van Kirk is out now

The expert: Mr Richard Mullender, hostage negotiator, creator of The Listening Institute

Being with family can conjure fond remembrances of gatherings past. It can also cause you to revert to childhood, to play your role in the family drama, which often involves sibling competitiveness. Hostage negotiator Mr Richard Mullender says that “winning” these encounters can be as simple as declining to participate in them. “That’s the first question to ask,” he says. “Do I need to take him on?” Rather than counter-attacking a spiteful remark, he says you might respond with something such as, “It seems to me I’ve upset you in some way. I’m wondering what it is that I’ve done.” This is what Mr Mullender calls compassionate assertion, which often results in learning the motivation behind the conflict. After you ask him to name your transgression, your brother might say, “No, you haven’t upset me at all. It’s just that blah, blah, blah, blah…” (The “blah, blah, blah” is years of familial trauma.) When he’s finished, apologise and compliment him. Mr Mullender says the goal is to diffuse the conflict by making him feel warmly towards you. Whether the feeling is reciprocated, Mr Mullender says, is immaterial. Just think of dealing with your family as business. “You don’t have to like the other person,” he says. “They only have to like you.”

Of course, your brother is probably extremely annoying, and you’re only human. Even Mr Mullender has succumbed to emotion. “I’ve had to walk away from a hostage negotiation because I practically said to the person on the other side of it, ‘Why don’t you jump, you prat. I hate you,’” he says. Mr Mullender suggests keeping the following story in mind. “Two people go into a newspaper shop every morning. The first person goes in and says, ‘Good morning. It’s really nice to see you.’ And the newspaper man just throws the newspaper. Second person goes, ‘Newspaper, please,’ and the newspaper man throws the newspaper at him as well. The next day, the same thing happens. The first person goes, ‘Good morning. How are you?’ Gets the newspaper thrown at him. After two weeks of this, the second person is infuriated. He says to the first person, ‘What is the matter with you? That man is constantly rude. He’s a real pain in the arse. I do not understand why you’re always happy with him.’ And the first guy says, ‘I do not give him permission to change my mood.’ And that is the answer to your problem. Don’t give him permission to change your mood.”

The expert: Ms Kim Kardashian West, star of Keeping Up With The Kardashians, criminal justice reform activist

Ms Kim Kardashian West may have become a celebrity because of her willingness to bare, well, everything on camera. But she became an influential social activist by understanding how to deal with people on the opposite side of the political spectrum – just as you will surely be forced to do when you go home for the holidays. Ms Kardashian West is married to Mr Kanye West, who has espoused many controversial views, including a since-retracted statement that slavery was a “choice” for the enslaved.

She has also had an impact on President Donald Trump’s criminal justice policy. After meeting with Ms Kardashian West at the White House, President Trump agreed to commute the sentence of grandmother and non-violent drug offender Ms Alice Marie Johnson and freed her from prison. He also signed the First Step Act, aimed at lowering the rate of reoffending. Though Ms Kardashian West opposes President Trump ideologically – she supported Secretary Hillary Clinton in the 2016 presidential election – she interacted with him in a way that made him feel like he was winning by supporting her cause. She empathised with his position, telling him that she, too, had only recently become aware of the horrors of incarceration. She expressed gratitude that a man in his position of power was listening to her, telling him it was “such an honour” to discuss it with him. And she was effusive in praising his evolution, saying it was “amazing” and complimenting his newfound compassion.

So, when Grandpa starts shouting about Brexit or immigrants or the dole, ask yourself, “What would Ms Kim Kardashian West do?” and be deferential of his position as family patriarch as you gently change his mind. Or just wait it out until he falls asleep after dinner.