In 1981, a researcher in Pennsylvania sat down and reviewed nine years of records from a surgical ward. He wasn’t looking for medications or methods, but for something no one had measured before: what patients saw through their windows. The result became one of the most cited studies in the history of environmental psychology—and it’s the same question that determines whether a blank wall in your home is a neutral condition or an active deprivation. This article explores what research actually says about understimulating rooms, and why choosing a poster is less decorative and more measurable than most people realize.
Fast facts: Roger Ulrich’s study was published in the journal Science in 1984 and drew on medical records from 1972–1981. Twenty-three patients who had undergone gallbladder surgery and had a view of a stand of trees were discharged earlier, received fewer negative notes from nurses, and needed weaker painkillers than twenty-three matched patients in identical rooms with a view of a brick wall.
The office that became a psychological experiment—and revealed the cost of emptiness
In 2010, Craig Knight and Alexander Haslam published a study in the Journal of Experimental Psychology: Applied with a title that sounds dry but describes something quite radical: a comparison of lean, enriched, and self-directed workspaces. The background was a conflict between two camps. On one side was the management tradition, which argued that a cleared room without distractions delivers maximum efficiency—no plants, no art, no personal items. On the other side was the design tradition, which argued the opposite.
The researchers set up office rooms in four different ways and had participants perform real work tasks in them. The stripped-down room had bare surfaces and nothing on the walls. The enriched room had plants and art arranged by the researchers. In the third version, participants decided for themselves what to hang. In the fourth, they were allowed to choose—after which the researcher came in and moved everything back.
The order of the results is what’s interesting. The stripped-down room performed worst on both productivity and well-being. The enriched room performed better. The room where participants chose the decor themselves performed best of all. And the fourth room, where they were first given a choice and then had it taken away, scored lower than the enriched room. So having your choice taken away was worse than never being asked.
Fifteen percent: the Cardiff and Exeter figure that moved the discussion out of the lab
The objection to laboratory studies is always the same: people behave differently when they know they are being studied, and an hour in a staged room says little about everyday life. So Marlon Nieuwenhuis of Cardiff University, together with Craig Knight of the University of Exeter, Tom Postmes, and Alexander Haslam, did something different. They went into real offices in the UK and the Netherlands and followed staff over time. Published in 2014, the study compared bare and enriched workspaces in three separate field experiments.
Three field experiments later, the figure was there: enriching a previously bare workspace increased productivity by up to 15 percent. Participants also reported greater concentration, better perceived air quality, and greater satisfaction with their workplace. What makes the study compelling is that it measured actual work performance over months, not self-reported satisfaction over a morning.
"A room without anything to rest your eyes on is not neutral. It is an environment that asks the brain to work without giving it anything in return."
One detail of the study design deserves emphasis. The researchers did not settle for asking staff how satisfied they were, which is the usual method in industry reports on working conditions. They combined self-assessments with objective performance measures from the employer’s own systems, and let the changes remain in place for months instead of measuring a novelty effect during the first week. That is also why the figure has survived twelve years of critical scrutiny without being revised downward.
It should be said plainly: both the 2010 and 2014 studies focused primarily on plants and art together, and on workplaces rather than homes. It would be dishonest to translate 15 percent into how much better you do the dishes in a kitchen with a poster on the wall. But the direction is clear, and it is repeated study after study: a bare space is not the baseline. It is one of several possible environments, and it performs the worst.
Ulrich’s windows: when a view of brick cost patients morphine
Roger Ulrich’s 1984 study predates both office studies and is still the most frequently cited. The setup was simple in a way that would be difficult to replicate today. At a hospital outside Philadelphia, patient rooms lined the same corridor. Some windows faced a small stand of deciduous trees, while others looked out onto a brown brick facade. Which room a patient ended up in depended on occupancy, not on anyone’s choice.
Ulrich pulled medical records for patients who had undergone surgery for gallstones between 1972 and 1981 and matched them in pairs by age, sex, smoking habits, weight, and year of surgery. Twenty-three pairs remained. Patients with a view of trees stayed in the ward for less time on average. Nurses’ notes contained fewer negative comments about them. And most notably, on days two through five after surgery, they were more likely to take milder medications such as acetylsalicylic acid or paracetamol, while patients facing a brick wall more often needed opioid analgesics.
Ulrich never claimed that a picture of trees would do the same thing as real trees. But the study opened up an entire field of research, and the work on nature images in healthcare settings over the following decades largely builds on his question. There is a direct line from the hospital wards in Pennsylvania to why so many people choose nature prints for rooms where they want to unwind. We’ve written more about this line of research in our article on nature prints and stress reduction.
The overlooked half of Knight’s findings: being able to decide for yourself
When Knight and Haslam’s study is referenced in interior design contexts, the story almost always stops at “art and plants are good.” That is the least interesting part. The truly surprising finding was what happened in the fourth room - the one where participants got to choose and then had their choices overridden.
Those participants performed worse than those who had never been given a choice. They reported lower well-being. The benefits of enrichment weakened when control was taken away from them. This says something about what really happens when something is hung on a wall: it is not just a visual stimulus, but a statement about who is in charge of the room.
That also explains why fully furnished show homes often feel lifeless even though everything is objectively well done. The Swedish interior design conversation in 2026 is moving in the same direction. IKEA’s own trend review for the year describes how the perfectly staged show home is losing ground to homes that tell you something about the person who lives there, with vintage finds, ceramics, textiles, and art with character. In practice, this is Knight’s third room, translated into a trend report.
Tip: If two of you share a room, let each person choose at least one image entirely on their own and hang it somewhere you both see every day. Research on overridden choices strongly suggests that a compromise image neither of you really wanted is worse than two images that pull in slightly different directions.
From hospital wards and offices to your hallway: what the findings actually tell us
The state of research supports three reasonably solid conclusions for a home. The first is that rooms where you spend a long time without actively looking at anything - the hall you walk through, the corridor, the room behind the screen you work at - benefit most from having something to rest your eyes on. That is where a stripped-back environment comes at the greatest cost, because that is where your eyes lack alternatives.
The second is that the choice should be yours. A poster you’re drawn to yourself statistically beats one someone else has judged to be more appropriate. This applies even if your choice is less in keeping with the rest of the decor. Knight’s fourth room is a reminder of what’s at stake: an environment someone else has chosen for you may be more beautiful and still work less well for the person living in it.
The third is that the amount matters in both directions. Ulrich’s window showed a group of trees, not a kaleidoscope. The studies on enriched workspaces used a few plants and a few framed artworks, not a surface covered from end to end. For rooms where you want to relax, that points to fewer, calmer subjects, ideally in the minimalist or botanical style. For rooms where you want to feel alert and energized, more expressive and abstract subjects work better.
There’s a practical point here that can easily get lost among p-values and effect sizes. None of the studies were about expensive art. They were about the space not being empty. If you’re standing in a room with nothing on the walls, the scientifically supported action isn’t to wait until you find the right piece. It’s to hang something you like, and replace it when you find something better. Waiting for the perfect choice is itself a bare environment, simply stretched out over time.
If you’d like to read more about how this research relates to well-being more broadly, we recommend our overview of art and well-being, as well as our article about art in the home office and focus.
Sources for those who want to read the originals: Ulrich’s article is published in Science, and the 2014 field experiments are indexed in PubMed. A worthwhile summary of the comparison between bare and enriched workspaces is available from the Association for Psychological Science.
Frequently asked questions about bare walls and understimulation
If you want to start where the research actually points - with your own choice rather than what’s statistically optimal - our full range of posters is open for you to browse. Find a design that catches your eye, hang it where your gaze most often falls, and let the brick wall stay outside the window.