IKEA: Come for the Swedish meatballs and the reasonably priced Scandinavian furniture, stay for the fight with bae about how many KALLAX shelves for your vinyl collection a sane household really needs. But it's not just you two: IKEA stores are basically designed to make you scrutinize every aspect of your relationship—in whatever state it may have been before you two headed in.

According to Dr. Gorkan Ahmetoglu, lecturer in business psychology at University College London, shopping at IKEA is such a trigger for couples because it's disorienting: "IKEA makes you visualize what it would be like to consume their products by presenting ready-made kitchens, model bedrooms, and bathrooms. The easier it is to imagine using a product, the more likely you are to want to buy it—it's called availability bias," he explained to me.

Shoppers also don't realize how deeply the store's perfect setup can affect them—it makes them feel literally at home: "A lot of these influences are subconscious, and even if people realize they're being manipulated, they're unable to resist it because the brain doesn't have the capacity to process these things properly," Dr. Ahmetoglu continued.

So, fights erupt. But what exactly are couples in IKEA fighting about? I headed to my nearest IKEA and walked around to overhear tidbits of couples' arguments. Since no fight is ever really about mattress toppers, I took four tidbits to Dr. Suky Macpherson, chartered psychologist and associate fellow of the British Psychological Society, who specializes in working with couples. I wanted to hear her thoughts on what those squabbles could tell us about the state of the respective relationships—and how to avoid falling into the black hole of coupledom during your own next trip to IKEA with an SO.

The Couple: A woman and a man near a selection of spatulas.

Man: "Are you sure this is the right place to get a cheese grater? Because I don't see any."
Woman: "Yes! Why do you always have to question everything I do?"
[Frustrated silence]

Dr. Macpherson: "This woman takes one remark and generalizes it to all communication in their relationship. 'Always' is never a useful word where relationships are concerned. There is a struggle for power within this couple—each person probably feeling like the other one is more in control. She seems to feel that the man has generally more power in their relationship, and this could very well be true."

The Couple: A man and a woman, the latter eyeing a rose gold lamp.

Man: "We have so much copper shit in the flat already, and I fucking hate it. Why do you always pick out the things you know I don't like? It's like you don't even care that we have to live in the same place."
Woman: "If you had good taste, I wouldn't have to choose everything for the both of us."
Man: "Just because we don't have the same taste it doesn't mean mine is bad."

Dr. Macpherson: "Shared living spaces are a problem—negotiating different tastes involves compromise, which some individuals are better at than others. There is a way around the fights this leads to: the good old give-and-take. Unfortunately, very self-oriented or narcissistic people are bad at this."

The Couple: A woman and a man standing by a basket.

Man: "I don't care what this is at this point, but you need to realize it isn't big enough to hold our washing. Can't I just go wait in the car?"
Woman: "No, you can't. I need your opinion. Honestly, whatever it is, it is big enough. I don't know what dreamland you live in."

Dr. Macpherson: "[The woman] wanted a shared experience, while the man wanted the experience to be over as soon as possible. I'm guessing that he doesn't understand the point of practical things needing to be attractive—he is happy to let her decide. I would hazard another guess and say the argument this couple was having points to a lack of shared vision, which is making her feel alone and unloved."

The Couple: Two men near the stationary section.

Man 1: "Right, so now you want the wrapping paper too. Which would make perfect sense if you ever bought anyone gifts. And I get the feeling I'm going to end up paying for it at the till."
Man 2: "You know, I get paid on Friday, and I'll transfer you the money then. Can't you just do this one nice thing for me?"

Dr. Macpherson: "It is a low blow to say the other never buys gifts, so the other hits back with the idea that the first never does anything nice for him. I think they both feel undervalued and perhaps exploited by each other. This spat reflects some deep tensions, because money can be a huge problem within a relationship. From the mention of 'gifts' and 'doing a nice thing,' you could also see that other aspects of the relationship are a problem—like time and attention."

I asked Dr. Ahmetoglu if there's any way couples can avoid getting into arguments in IKEA. "Couples need to make sure they have a shopping list they're both happy with in advance and stick to it religiously," he replied.

If that fails and the shopping spree still ends in tears and frustration, Dr. Macpherson says couples shouldn't be too hard on themselves: Background stress worsens existing tensions in relationships, and if there's one thing IKEA does, it's deliver a shitload of background stress to your relationship.