You tell yourself you're just going to run in for that one thing, and you come out pushing a red cart full of all the things you didn't even know you needed (but now can't live without).

For most of us, this is just called a Target run, but the phenomenon also goes by another, more scientific name. As Refinery29 reports, its called the "Target Effect," and it isn't just happening to you, mama.

Dr. Kevin Chapman, a psychologist (and Target shopper himself) tells Refinery29 that attention to detail (and excellent hiring) when it comes to design is one reason you find yourself loading the trunk with Target bags when you just meant to run in and grab toilet bowl cleaner real quick.

"You have good people in the marketing department at Target, and they have really good designers who have created such an ambient atmosphere for people. It's really well lit at Target, right? There's a lot of color at Target. It's pretty consistent throughout the store and generally, that's going to make people feel happier," he says.

Target's test store: Math and magic



Target takes making us happy (and making us spend money) so seriously that the company has a (formerly) top-secret test store inside its Minneapolis headquarters, Fast Compan y reports. It's literally a full-size Target where designers can test out plans and product placement because the Target effect is a byproduct of the Target experience.

Items on tables sell better than items on hanging racks, and where a product is displayed when you stroll by on your way to get cat litter may make you more likely to toss it in the cart.

"So when something goes into a prominent position in a store, whether it's a key focal table or anywhere else, we basically say that it's got to pay for its real estate," Erika De Salvatore, the VP of visual merchandising at Target told Fast Company. "So we have some financial conversations during that time, too. Visual is both math and magic."

Why we want to bring display items home



The way Target designs the product displays also helps our mind's eye see those products in our own spaces. Target's Vice President of Store Design, Joe Perdew, told Refinery29 that's why the retailer adds "dynamic product vignettes throughout the store that help guests envision how things will fit into their lives."

So when we walk past the Hearth and Home display, the artful arrangement really does make us feel like we need to have that bit of decor, because we can totally see where it would fit in our home. And so into the cart it goes.

Light, bright and remodeled



Over the last year, Target's been making sure that the design and aesthetic of its stores makes shopping easier, and makes us happier. The company is currently in the process of renovating over 1,000 stores across the U.S., a process that will be complete by the end of 2020.

"We have to use all of our assets—the building spaces, fixtures, interior design, lighting, products—to tell a story and make the whole shopping trip as easy and inspiring as possible for guests," Perdew said in a recent Target corporate release.

Translation: It's not your fault you get more than you came for during a Target run. The whole place is designed to make you do it.

Ease vs. inspiration



There is some good news on the horizon for those of us who don't have a lot of willpower: Part of the remodeling process is seeing stores with two entrances have one set of doors designed around "ease" and the other around "inspiration," says Perdew.

"The 'ease' entrance might have features like Drive Up parking spaces, an online Order Pickup counter, self-checkout lanes and grab-and-go grocery and essentials right there as you walk in—everything the guest needs to get in and out quickly," he explains.

So if you just need laundry soap, use the "ease" entrance, but if you want to surrender yourself to the Target effect and go to mama's happy place, walk through the inspiration doors. Just know that you are for sure coming out with a full cart.