There is a measurable sweet spot for how much a subject should contain. A nearly empty poster leaves the eye restless and understimulated; an overcrowded one tires the eye after a few seconds. As early as the 1870s, German psychologist Wilhelm Wundt sketched a curve that predicts roughly where the pleasant middle ground lies—and a century of research has both confirmed and complicated it. This article is about visual complexity: why the brain rewards subjects with just the right amount of content, what happens in your mind when you’re drawn to a particular image, and how you can apply this insight when choosing art for your wall.
The question is surprisingly practical. Two people can stand in front of the same poster, and one finds it calming and restful while the other finds it boring. Another subject feels lively to one person and chaotic to the other. Behind these reactions lies not just taste, but a documented psychological mechanism that art researchers have measured in laboratories since the mid-20th century.
Quick facts: The relationship between complexity and liking is called the Wundt curve, after Wilhelm Wundt (1832–1920), who founded the world’s first experimental psychology laboratory in Leipzig in 1879. Canadian psychologist Daniel Berlyne turned the idea into a testable model in books published in the 1960s and ’70s, showing that liking often follows an inverted U shape as the complexity of a subject increases.
What does research actually say about complexity and liking?
Daniel Berlyne, who worked at the University of Toronto, built his theory around what he called collative variables: novelty, complexity, uncertainty, and conflict. These are qualities of an image that force the brain to compare, interpret, and solve something—and therefore raise what Berlyne called the subject’s arousal potential, or how much it activates us. Too little, and the image is uneventful. Too much, and it becomes tiring. Somewhere in between lies the peak of the curve, the point at which we like what we see best.
Berlyne’s inverted U has become one of the most frequently cited ideas in empirical aesthetics, but modern research has shown that reality is richer than a single curve. A particularly clear review was published in the journal Frontiers in Human Neuroscience in 2016 under the title “Berlyne Revisited.” When researchers controlled for how familiar a subject was, they found that different aspects of the aesthetic experience respond differently to complexity: perceived beauty followed an inverted U shape, while pleasantness declined and liking alone increased as complexity rose. In other words, “how beautiful” and “how much I like it” are not the same question, and they do not respond in the same way to how much a subject contains.
This matters when you choose a poster, because it explains why you can admire a busy, detailed work in a gallery but still choose something calmer for the bedroom. Beauty and everyday comfort pull in different directions on the complexity scale.
From Wundt’s curve to the measurable sweet spot of fractals
The curve’s history is longer than you might think. As early as the 1870s, Wilhelm Wundt was interested in how stimulation relates to pleasure, and sketched the relationship as an arc: displeasure when there is too little, pleasure in the middle, and displeasure again when there is too much. Almost a hundred years later, Berlyne gave the arc a scientific framework. And over the past two decades, researchers have been able to put actual numbers on "just the right amount."
The most concrete figure comes from research on fractals - nature’s self-repeating patterns, where the same shape recurs at ever smaller scales, as in a fern, the branches of a tree, or a coastline. Fractals are measured using what is called a fractal dimension, D, where a low value means sparse and simple, and a high value means dense and intricate. Several studies of images in interior settings show that both visual interest and preference peak when the fractal dimension is around D = 1.5 to 1.7 - a moderately high value, neither the simplest nor the most intricate. It’s the Wundt curve expressed in mathematics, and it happens to coincide with the complexity of many nature motifs that people around the world are drawn to.
"The eye wants something to do, but not too much - just the right amount of complexity isn’t a compromise, but the point at which looking itself becomes enjoyable."
That explains why botanical motifs and stylized landscapes work so well on a wall. They offer enough detail for the eye to explore, but are organized enough not to overwhelm. If you want to explore this mechanism further, we’ve written more about fractals and why nature’s patterns calm us, a topic closely related to this article but one that delves deeper into the physiology of stress.
Why the beautiful curve isn’t the whole story
If the research were simple, we could settle on a single ideal value and buy accordingly. But it isn’t, and studies from recent years are careful to point out three complications.
The first factor is individual differences. When researchers have analyzed results person by person instead of pooling the whole group, the neat inverted U-shape has sometimes dissolved. It is clearly visible in the average across many participants, but at the individual level, some people may like a subject more and more as it becomes more complex, or vice versa. One reasonable interpretation is that the group curve is partly a statistical composite of very different tastes. For you as a buyer, this means your own peak may lie further toward the detailed or minimalist end than average – and that is perfectly valid.
The second complication is familiarity. The more we have seen a subject, the more easily the brain processes it, and the less “complex” we perceive it to be. A work that seemed cluttered at first glance may feel harmonious after a month on the wall. This is the same mechanism behind how a painting grows on us over time, and it means that perceived complexity is not a fixed property of the subject, but something that changes as you get to know it.
The third factor is order. A 2017 study in PLOS ONE showed that mirror symmetry lowers the perceived complexity of a pattern: the brain reads two mirrored halves as simpler than they “really” are, because symmetry provides a shortcut. This means that a detailed but symmetrical subject can feel calmer than a sparser but more disordered one. Complexity is therefore not just about how much is in the image, but also how well-organized it is. Those who choose graphic posters with a clear structure often find that even fairly busy subjects feel balanced, precisely because the composition is orderly.
If you want to understand how “order” and “ease” relate to beauty, we recommend our article on processing fluency and why some art feels beautiful, which explores the related question of how easily the brain interprets an image.
How to use the complexity curve when choosing a poster
The practical value of this research is that it gives you a tool to think with rather than a rule to follow. The basic principle is easy to remember: match the complexity of the subject to how the room is used and how long the eye is meant to rest there.
In rooms where you want to unwind – bedrooms, reading nooks, meditation spaces – it pays to stay just below the peak of the curve, toward the calmer end. Minimalist landscapes, a single botanical branch, a quiet abstraction. The eye has something to rest on without being stimulated. Our selection of minimalist posters is deliberately positioned at that end of the scale.
In rooms where you move around, socialize, and want energy – the hallway, dining area, or home office – the wall can handle more. There, you can lean toward the more detailed side, with abstract posters that have several layers or bustling botanical compositions your eyes can return to. A subject with high arousal potential works best where your eyes encounter it in passing, rather than staring at it for an hour.
Tip: Try the three-second test with a piece you’re considering. If it feels empty and you’re done with it right away, it’s below your personal sweet spot. If it’s hard to know where to look, it’s above it. The poster that keeps drawing your gaze back after a few seconds without making you feel stressed is probably right in the middle of your own curve.
One final practical point: symmetry and orderly composition let you take in more detail without losing a sense of calm. If you want a rich subject in a tranquil room, choose one with balanced rather than scattered forms. That gives your eyes something to take in and your mind some peace. Botanical subjects are particularly well suited to this, and our range of botanical posters includes everything from almost graphically simple branches to lush, detailed compositions – so you can find exactly the level of complexity your room calls for.
Combining several subjects on the same wall follows the same logic. A wall with lots of small, bustling works can quickly go over the top and feel cluttered; one with just a single pared-back work can feel uneventful. Pair a detailed anchor piece with a few calmer ones around it, and the wall as a whole finds its balance. We touch on the principles behind how a collection comes together in our article about visual balance and the golden ratio.
Frequently asked questions about visual complexity
The research described here comes from empirical aesthetics and neuroaesthetics, including the review “Berlyne Revisited” in Frontiers in Human Neuroscience and the study on mirror symmetry and perceived complexity in PLOS ONE. If you want to apply this insight to your own wall, the easiest way is to start looking at designs with the curve in mind: ask yourself where on the scale this particular room should land, and trust your eye to recognize its own sweet spot when it sees it. Explore the full range and let the three-second test guide you to the poster that holds your gaze without overwhelming it.