If you’ve never seen a master lathe operator at work, I highly recommend it. Deft movements and practiced flourishes turn a block of spinning wood into a bedpost, top, bowl or some other circular object, each motion peeling away curls of wood to uncover the beauty hidden inside.

It’s hard to explain why the motions feel so right, but there is an undeniable allure to the work, as if it scratches an itch you didn’t know you had.

As it will, the internet discovered lathe turners — and pastry chefs, calligraphers, industrial machines, baristas and 3-D printers — and found it liked them. Grouped under the clickbait-friendly term “oddly satisfying” you’ll find video compilations—often attracting millions of views—of people and machines doing repetitive tasks with skill and precision.

There’s something inexplicable about their appeal, as the befuddled comments that accompany the videos attest. No one can articulate precisely why they can’t tear their eyes away. The titles that adorn most of them seem to actually sum up their appeal quite well: oddly satisfying, indeed—but why?

That Goldilocks Feeling

Hard answers may be lacking, but the oddly satisfying videos appear to tap into a subconscious urge toward what psychologists call a “just right” feeling. It’s the sensation that arises when we’ve put things in order, and serves as a useful cut-off point for simple tasks. It’s also what often goes wrong in individuals with Obsessive Compulsive Disorder (OCD). For reasons not quite understood, some people with OCD don’t interpret the sensory cues that indicate the job is done, leaving them searching fruitlessly for a sense of completion. The quest for finality often leads to things like continually arranging objects, checking doors repeatedly to see if they are locked or cleaning things uncontrollably.

In fact, OCD was the first thing that jumped to mind when Sarah Keedy, the director of the Cognition-Emotion Neuroscience Laboratory at the University of Chicago, first viewed an oddly satisfying compilation.

“It was nothing I sat around and thought about, it hit me right away,” Keedy says. “It was truly an overwhelming sense of this is a series of visual depictions of things that struck me as rewarding experiences that … [people with OCD] tend to be going for to a pathological degree.”

Gears fitting snugly together and swirls of frosting alighting perfectly on pastries seem to satisfy an existential longing. In a world of chaos and inelegance it can be reassuring to see order, control. If anything, the videos reveal that people with OCD aren’t anomalous in their desire to bring a pleasing equilibrium to their lives. These videos may offer a glimpse into the catharsis that the disorder denies those affected by it. Watch a few videos and see how comforting it feels. Now imagine you were always just on the edge of achieving that sensation.

The oddly satisfying sweet spot was most recently examined by researchers from Spain. They gave people with OCD and a control group a word recall task and cut them off in the middle of completing it. They theorized that a task involving ordering and checking something, words in this case, would activate their internal “just right” sensors. Stopping them before finishing would then trigger unease. Their hypothesis was right: People in the control group felt uncomfortable when something was left undone, and for the OCD participants, it was even worse (two of them even mailed completed lists to the researchers afterwards to satisfy their urge for finality.)

Isn’t This Intuitive?

The researchers’ findings are hardly groundbreaking; of course we don’t like to leave tasks unfinished. Extrapolating this idea to the oddly satisfying videos, it’s fairly clear why watching a ball fit neatly into a cylinder is appealing. But this phenomenon can’t be boxed up so neatly.

These compilations also feature equally satisfying clips that depict the destruction of order—the opposite of completion. Kinetic sand being cut, jello falling, melted chocolate being poured over a dessert to crack it open — all of these things also fall under the “oddly satisfying” umbrella, but there’s no happy ending per se. Perhaps, there’s something else in play.

Instead of thinking about the videos from a holistic perspective, as Keedy does, Ladan Shams, a psychology professor at UCLA whose lab examines multisensory perception, thinks of them in terms of their constituent parts: shapes, colors and movements. Shams and researchers like her want to understand the elements that guide our preferences; preferences that are so basic we don’t even think about them.

“There are a lot of things that influence our preferences that we are not aware of consciously, and which may relate to even very low-level processing in the brain,” Shams says.

Watching a video of a wooden bowl materializing from a spinning lathe is pleasing, but only because a series of small, discrete actions have checked off the boxes that underlie what we think “pleasing” is. Researchers are only beginning to break down our sensory experiences into their constituent parts, and Shams says that the oddly satisfying videos serve to highlight the inadequacies of the field so far.

“I think this phenomenon may be underlining the need to do more research in this area, to understand what drives our preferences,” she says. “That, in my opinion, is the take-home message from these videos.”

Shams’ lab is currently studying the ways personality traits and emotional states shape our preferences, with the goal of discovering how both genetics and even transient conditions play into the equation.

What is Quality? It’s a Tough Question

In a way, the question is reminiscent of the debate around what makes great art. It’s prohibitively difficult (and some would say counter to the notion of art itself) to describe in scientific terms what makes a Picasso or a Monet appealing. Getting to the core of the issue, however, could give us more than better marketing tactics or more satisfying consumer goods, however. Our preferences are integral to who we are, and knowing what shapes them lets researchers peer deeper into the human psyche.

This line of scientific inquiry is sure to take us down many paths and generate numerous hypotheses, however. That two researchers emerged from the YouTube rabbit hole with totally different takes hints at the difficulty of the task. Whatever is going on in these videos stimulates our neurons in complex and multifaceted ways. Scratching a “just right” itch and offering up perceptual pleasure might be just two of the many ways oddly satisfying videos gratify us.

When it comes to explaining the allure of these videos, there are, sadly, no satisfying answers.