We’ve known intuitively for centuries that spending time in nature can give us a boost. But it’s only recently that scientists have begun to identify exactly what it is about the outdoors that has such a powerful effect on our mood and our minds. This week, psychologist Marc Berman explores how spending time in nature can actually undo some of the harmful effects of our modern lives.
Do you have follow-up questions, comments, or stories about nature’s effect on the mind after listening to this episode? If you’d be comfortable sharing your thoughts with the Hidden Brain audience, please record a voice memo on your phone and email it to us at [email protected]. Use the subject line “nature.” Thanks!
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Transcript
The transcript below may be for an earlier version of this episode. Our transcripts are provided by various partners and may contain errors or deviate slightly from the audio.
Shankar Vedantam: Feeling a little frazzled as 2025 comes to a close? Put your to-do list on pause and join me for an evening of science, storytelling and connection. I'm bringing Hidden Brain's Perceptions Tour to the Orpheum Theatre in Los Angeles on November 22nd. I'll be sharing seven key psychological insights from the first decade of the show. To get your tickets, go to hiddenbrain.org/tour. I'm also excited to announce that we are adding more dates to the tour for 2026. I'll be in Philadelphia on March 21st and New York City on March 25th. Hidden Brain listeners get a first crack at tickets to those shows. The pre-sale begins at 3 p.m. Eastern on November 3rd and runs through November 5th. To get your tickets to our 2026 shows, go to hiddenbrain.org/tour and use the promo code BRAIN. No promo code is needed after November 5th. I hope to see you there. And here's today's show. This is Hidden Brain. I'm Shankar Vedantam. When we are facing struggles with our thoughts or our emotions, many of us turn first to medication or therapy as solutions. The share of American adults reporting they took prescription drugs for mental health conditions stood at 19% in 2022. That's according to an analysis of government data by the Kaiser Family Foundation. That's millions of people taking drugs for anxiety, for depression, for attention deficit disorder. Millions more are in therapy, working through their challenges with a counselor. For many people, such measures are enormously helpful, even essential. At the same time, it may be the case that we are overlooking a potential source of relief that is literally right outside our door. This remedy costs nothing, has no known side effects, and is often delightfully pleasant. We are talking about spending time in nature. The capacity of the natural world to soothe and refresh our sensibilities has been known for centuries. But it's only recently that scientists have begun to identify exactly what it is about the outdoors that has such a powerful effect on our moods and our minds. "Nature is filled with curved edges. And one thing that we found in our research is that people really like images that have more curved edges, even built images. So images of architectural scenes that don't have any nature in them. If the architecture has more curved edges, people tend to like that architecture more." Shankar Vedantam: If you struggle with the ability to think clearly, to focus your attention, to control maladaptive behaviors, this episode and a companion story on Hidden Brain Plus are definitely for you. Why nature is good medicine, this week on Hidden Brain. Many of us enjoy an occasional stroll in the park or a hike in the woods. It feels good to see beautiful trees, to hear birds sing, and to breathe fresh air. But might nature offer more than a fleeting respite from our time-pressured, harried lives? At the University of Chicago, psychologist Marc Berman studies how spending time in nature can help our minds. Marc Berman, welcome to Hidden Brain. Marc Berman: Thank you for having me on the show. Shankar Vedantam: I want to start with a few examples of the phenomenon you've been studying, Marc. In the late 1930s and early 1940s, the artist Jackson Pollock was living and working in New York City. What was his state of mind, especially after his father died in 1933? Marc Berman: Well, it wasn't good. You know, Jackson Pollock moved from California to New York to be with his brothers. When his father died, he had, you know, extreme depression. And alcoholism and, you know, he was taking sculpting classes, but he was just not very happy, very mentally disturbed, having a lot of problems with depression and alcoholism. Shankar Vedantam: I understand that Jackson Pollock's volatility, combined with this heavy drinking, led to some very public and private meltdowns? Marc Berman: Yes. At an art gallery, he yelled that he was a much better artist than anyone that had their art being displayed in the art gallery. And subsequently he lost the ability to be in that art gallery. He got into an argument one time and was so angry that he turned over a whole table that had all of the food on the table and like 12 roast beef dinners were just flying all over the place that it was a huge mess, essentially ending the dinner party right then and there. Shankar Vedantam: So at one point, he gets romantically involved with a painter, Lee Krasner, who wants to get him away from New York City. What was her plan, Marc? Marc Berman: I think she wanted to get him out of the New York environment, where, you know, there were so many bars that he frequented, to remove him from that environment, maybe also removing him from some of the people that he was hanging around at the time, and to maybe sort of take him to a more natural, a quieter environment out in Long Island, that the fresh air might be good for him. Shankar Vedantam: Do you know what this place was like that they ended up moving out to? Marc Berman: I think it was like in Springs, Long Island, which is in East Hampton, and it was a pretty modest home, but it had like a barn and maybe an acre of land. Marc Berman: There was a lot of sort of beautiful nature to look at, and it did seem to inspire some changes in Jackson. Shankar Vedantam: What changes? Marc Berman: He was no longer as volatile. He was no longer as depressed. And it seemed like being in that environment was also quite inspirational for his artwork. He would purchase these large yachting canvases, and he would spread them out in the barn, in the backyard of his home. And he started to do his famous paint splattering, where he would spill the paint and do different things with brush strokes that were more organic and matched the organic properties of nature. And I think people think that being out in nature inspired this new art form for him. Shankar Vedantam: Now, I understand that he continued to have trouble the rest of his life. So it's not like being out in nature was a panacea. It's not like he basically, you know, turned over a completely new leaf. But it did sound as if he got his life together, partly as a result by being out in nature. Marc Berman: That's right. And, you know, we would never argue that depression or alcoholism are easy problems to solve. But it does seem to be the case that people's interactions with nature can be very beneficial for people who are suffering from depression and anxiety or ADHD, even things like PTSD. So while, yes, I wouldn't say that being in nature can solve all of these problems, it does seem to be the case that being and interacting with nature can help with many of these problems. Shankar Vedantam: In more recent years, Marc, the Naval Health Research Center in San Diego, California, has run a program to treat members of the US military. What kinds of problems are these veterans struggling with? Marc Berman: Often they have problems that involve maybe developing depression or post-traumatic stress disorder, PTSD. Some of them have traumatic brain injury or TBI. There's a lot of physical and mental health conditions that unfortunately a lot of these service members develop from their time in the military. Shankar Vedantam: So the psychologists who work with this population take an unusual approach to treatment. What do they do? Marc Berman: Yeah, so they actually had about 20 or so of these military veterans engage in a six-week surf therapy, therapeutic session, where for three or four hours in a group setting in a southern California beach, they taught these veterans how to surf, thinking that this kind of program could actually be beneficial to them from a mental and physical health perspective. Shankar Vedantam: I'm curious, why surfing? Marc Berman: That's a good question. I think in part because they had some feeling that being in nature might be beneficial, so being out in the ocean, seeing the ocean waves, being on the beach, having the sights, smells, and even the textures of the ocean could be beneficial. It was also somewhat of a social activity because they were taking these veterans out in groups of about 20 people, and when you're trying to catch a wave, sometimes there's a lot of sitting on your board, waiting to catch your wave. And of course, too, there's also an exercise component to it. Surfing is challenging. It's a hard physical exercise, and I think they probably also thought that that would be helpful as well. Shankar Vedantam: So the psychologists at the Naval Health Research Center wrote up the results of the surf therapy program in a journal article published in 2019. Shankar Vedantam: What did they report? Marc Berman: They found that PTSD symptoms and depression symptoms went down when these surfers were involved in the program, and they also had sort of improved moods, so more positive moods, less negative moods, and that the severity of their depression and anxiety symptoms tended to decrease amongst these surf therapy participants. Shankar Vedantam: I understand that you yourself sought solace and comfort in nature when you were a stressed out graduate student at the University of Michigan. Where would you go when you were feeling at your wit's end, Marc? Marc Berman: Yeah, the two main places that I would go to were Barton Park, that was kind of right on the Huron River in Ann Arbor, Michigan. And I would also often go to the Ann Arbor Botanical Gardens, which was a little bit farther away from campus, a little bit farther away from where I lived, but a very beautiful botanical garden that had a lot of nature trails that you could walk on. Shankar Vedantam: I understand there was one particular tree at Barton Park that caught your eye? Marc Berman: Yeah, there was this gigantic oak tree in the middle of the trail on Barton Park. It was almost off by itself, this singular oak tree that had a really, really giant trunk. And it always kind of caught my eye. You definitely could hear the wind kind of rustling through its leaves. And, you know, sometimes I even felt like I would kind of, you know, talk to this majestic tree that I kind of would anthropomorphize this tree that it could listen to me and maybe kind of help me sort out some of my problems. Shankar Vedantam: I understand that toward the end of your time in graduate school, your longtime girlfriend broke up with you. Tell me what happened and the effect this had on you, Marc. Marc Berman: Yeah, it was very difficult. And I'm sure a lot of people have experienced difficult breakups. But it was, you know, one of my more serious relationships. Maybe I thought this would be a very long term, you know, relationship, possibly somebody that I would get married to. So that was a big blow to me. And I was seeing friends of mine that were getting married or buying houses or, you know, having kids. They all seemed to be kind of passing me. So it was a very kind of hard time. A lot of things compounded where it did seem like, you know, a lot of my friends were passing me by. And I was kind of stuck still maybe being a kid, not really having grown up yet. Shankar Vedantam: I'm wondering how you dealt with this breakup and whether nature played any role in you finding yourself. Marc Berman: Well, it certainly did. I immediately went to Barton Park and looked for that big oak tree to share my sorrow and try to see if that oak tree could heal me a bit. Shankar Vedantam: Standing beneath the majestic branches and the gently rustling leaves, Marc confided his sorrows to the tree. Marc Berman: I basically said, you know, it's over with me and Heather. Now I've got to move out and find a new place to live. I'm single, I don't have much money, and I'm nearly 30. My friends are buying houses, they're getting married, they're having kids themselves. You know, I just felt like a loser, and kind of thinking, what am I doing wrong? Shankar Vedantam: What was the effect of saying this to the tree? Marc Berman: Well, initially, it didn't help too much, but I think it felt good to get it out. When you're in front of majestic nature, and, you know, to me, this tree was fairly awe-inspiring, it does sort of make your problems feel a little bit smaller that we're part of something larger, and the vastness of nature can make us feel small, but I think in a good way where we realize, you know, we're part of something bigger, and, you know, while I certainly was not feeling good at the time that it would pass, and I would get back to being myself again. Shankar Vedantam: You know, sometimes when I'm out in the woods and I see one of these trees that's been around for 50, 60, 70, 80 years, I can't help but think about all the things that this tree has seen, and all of the historical events that it's witnessed. I mean, there are trees around that are 200 years old, and you realize that they have seen and been around so much. And in some ways, as you talk to the tree about your breakup, you're putting things in perspective, not just spatially, but also in a question of time. Marc Berman: Yeah, I think that's a really, really good point. And also too, that you're describing these trees that can be so old. They do kind of have sort of the wisdom of a grandparent, it seems like. You know, they have deep roots, they have a long history. It seems like there is some wisdom that's contained in these trees. Shankar Vedantam: An artist finds relief from his roiling emotions and destructive drinking alongside a creek in rural Long Island. Military veterans recover from trauma as they surf the waves of the Pacific. And a scientist finds that in the midst of stress and heartbreak, a tree can provide the soothing support he needs. What is it about being outdoors that soothes and heals us, allowing us to become focused and productive? When we come back, the science behind the power of nature to restore our minds. You're listening to Hidden Brain. I'm Shankar Vedantam. Shankar Vedantam: This is Hidden Brain, I'm Shankar Vedantam. Have you had experiences in nature that have proved restorative or cleansing? If you have a story about a time in your life when the great outdoors proved helpful to your inner state of mind, please find a quiet room and record a short voice memo. Email it to us at ideas at hiddenbrain.org. Two or three minutes is plenty. Please use the subject line, nature. Marc Berman is a psychologist at the University of Chicago. For many years now, he's been interested in the science of why nature seems to help our minds. Marc, one of the leading lights in your field is a man named Roger Ulrich. When he was a teenager, he was often sick. How did he turn to nature to help him? Marc Berman: Yeah, he actually told me that when he was a kid or a teenager, he suffered from staph infections and some kidney disease, and he would spend a lot of times, you know, sitting in clinics or hospitals, but he much more enjoyed recuperating at home where he would kind of lie down and out of the window, there was a giant pine tree outside his window that he would look at quite often when he was recovering from these illnesses. Shankar Vedantam: So he went on to become a researcher, and in the early 1980s, he conducted a remarkable study at a hospital in Philadelphia. What did he study and what did he find? Marc Berman: Yeah, it's a really incredible study, and I would say one of the most seminal works in kind of environmental psychology. And what Roger did was he studied patient recovery from gallbladder surgery on a single corridor in a hospital in Philadelphia. And what Roger was interested in looking at were the views out of the windows of these hospital rooms. So some of the hospital rooms had some modest views of nature out of the window, like some trees or some shrubs or some grass. But other rooms on this hospital corridor had views of, like, a brick wall of the other side of the hospital. And Roger was interested in seeing, does the room that people are in and the view that they have out the window have any impact on recovery from gallbladder surgery? And incredibly, he found that patients that had the views of modest nature out of their window recovered about a day earlier from gallbladder surgery compared to the patients who had rooms of a brick wall. In addition, the patients that had the rooms with the nature view, they used less pain medication than the patients that had the views of the brick wall. And, you know, people might be thinking, well, maybe patients who were healthier or younger or wealthier, maybe they got the views of nature and the other patients didn't. But that wasn't the case. These patients were basically randomly assigned to these different hospital rooms. They were just, whatever room was available, that's the room that they got, which is kind of like doing an experiment. And it's just amazing that being randomly assigned to the room that had the modest nature view could speed recovery and also cause people to use less pain medication. Roger was really interested also in stress and stress responses. So he believed that interactions with nature could remediate stress responses. And he thought that was the mechanism behind why interacting with nature was having different beneficial effects. Shankar Vedantam: Over time, many other theories have been advanced about why nature could have positive effects on our minds. One came from the evolutionary biologist EO. Wilson. He called it the Biophilia Hypothesis. Marc Berman: So the Biophilia Hypothesis, in a nutshell, is this idea that humans have an inherent love of nature and the natural world and other living organisms. And these tend to be places that we would say would be very good habitats for humans to live in. And there was actually a researcher, J. Appleton, who proposed this other theory called Prospect Refuge Theory, that environments that had high prospect, meaning places where you could draw food and water, but also that had high refuge, places where you could kind of hide and be safe, would be the most kind of preferred environments. And that also kind of matches this idea of humans kind of liking natural environments that have a lot of plants and trees, but also water. Shankar Vedantam: As you began to conduct your own research in this field, Marc, you were working with a mentor named Stephen Kaplan. Steve believed that the benefits of exposure to nature had much to do with attention. And he would often talk about how humans have two distinct types of attention. What are these two forms of attention? Marc Berman: Yeah, so Steve coined or developed this hypothesis called the attention restoration theory, and he did this in partnership with his wife, Rachel Kaplan. And one of the main tenets of attention restoration theory is that humans have two main kinds of attention. And one kind of attention is called directed attention. And that's the kind of attention where you as the individual person are deciding what to pay attention to. So presumably, anybody listening to the show is deciding to pay attention to what we're talking about. And this directed attention is the kind of attention that we use a lot in schools and at work. It's thought to be fatigable or depletable that you can only sort of direct your attention for so long before you become mentally fatigued and you can't really focus anymore. And we've all had that sensation kind of at the end of a long workday where you might be just staring at the computer screen and nothing's really happening and you just can't focus or concentrate to get your work done. We would call that a directed attention fatigue state. And that's a good time to take a break. Shankar Vedantam: So Steve argued that there was a second form of attention as well. What is the second form? Marc Berman: Right, in the second form of attention, Steve called involuntary attention. And that's the kind of attention that's automatically captured by interesting stimulation in the environment. So bright lights, loud noises, they automatically capture our attention, and we don't really have any control over it. And it's thought that involuntary attention is less susceptible to fatigue or depletion. And you don't often hear people say, oh, I can't look at that beautiful waterfall anymore. It's just too beautiful. It's too tiring to look at. I have to stop looking at it. So the idea behind attention restoration theory is that if you can find environments that don't place a lot of demands on directed attention, while simultaneously having interesting stimulation that activates the involuntary attention, you could restore or replenish this precious directed attention resource. And we think that a lot of natural environments sort of meet these criteria. Shankar Vedantam: Not all forms of involuntary attention are restorative. Compare the experience of watching ocean waves at a beach, for example, to the experience of walking through Times Square in New York City. Marc Berman: When you're looking at those waves at the ocean, it captures your involuntary attention, but it doesn't really capture all of your attentional resources. You can kind of mind wander and think about other things while you're looking at those waves. When you're walking through Times Square, it's also very interesting. There's a lot of really interesting stimulation in Times Square that automatically captures involuntary attention, but it sort of captures all of your attentional resources. You can't really mind wander or think about other things when you're in Times Square. And Steve and Rachel thought that that kind of stimulation is not really going to be able to rest our directed attention abilities, that it might actually fatigue us even further. Shankar Vedantam: This is a crucial point, and I want to take a second to underline it. Watching a waterfall, or the waves, or the clouds drifting across the sky allows our minds to relax, to wander. These softly fascinating scenes are very different than the harsh demands of being in a hyper stimulating environment like Times Square. You cannot let your attention wander. You might get bumped into by hordes of tourists, or run over by a cab. Scientists have also theorized that natural landscapes and soundscapes are just more easily absorbed by our brains. Marc Berman: There are certain simulation in the environment that our brains process more fluently, that it's just easier to process certain stimulation. And that's also kind of related to soft fascination, that softly fascinating stimulation might also be sort of easier to process. But what does that really mean? And so we've started to try to quantify what it means for different stimulation to be processed more fluently or more easily. And it seems like that seems to be occurring more for natural images versus urban images. Shankar Vedantam: You know, it's interesting, as I'm sitting here talking to you, I'm able to look out at a window and I'm seeing a tree, and the tree has, you know, probably 5,000 leaves that I can see right now through the window. But of course, I'm just taking in all of those leaves in one big bite. I'm not actually noticing that each of those leaves has a different vein structure and the light is hitting that leaf differently. I'm just taking it in as a tree. And that's what you're talking about here. Marc Berman: That's right. That's right. Versus in the urban environment, you might actually be cataloging all the different objects, you know, that there's a Volkswagen Beetle, a bicycle, you know, Gothic architecture. And, you know, we're just labeling and quantifying all of that information, which is taking up more room. Whereas what you're saying, when you're looking at that tree, you're compressing that representation to just be a tree and not to, you know, something that's got 5,000 little extra parts for every single leaf. Shankar Vedantam: One particular aspect of natural settings that might affect us is the prevalence of curved edges. Talk about this idea, Marc, why would this matter? Marc Berman: Well, it's interesting that natural settings tend to have more curved edges. You know, if you imagine a tree, a tree's got curvy branches, tend to have curvy leaves. An ocean, the waves are curvy, the coastline is curvy. So nature is filled with curved edges, and one thing that we found in our research is that people really like images that have more curved edges, even built images. So images of architectural scenes that don't have any nature in them, if the architecture has more curved edges, people tend to like that architecture more. Shankar Vedantam: Another aspect of natural settings that might affect our minds is the presence of what mathematicians and physicists call fractals. What are fractals, Marc, and how do they show up in nature? Marc Berman: Yeah, so if we imagine a snowflake, the snowflake has a characteristic shape. If we put that snowflake under a microscope and zoom in, you'll also see some of the same shape. And if you zoom in some more, you also see the same shape. So that it doesn't really matter what spatial scale you look at the snowflake, it's got the same characteristic shape. So we would say then that the snowflake is scale-free. It doesn't matter what spatial scale you look at the snowflake, it's got the same characteristic shape. Or mathematicians would say that that snowflake is more fractal. It's got more of a fractal aspect to it. And you can imagine the same thing with a tree. A tree has a trunk, which then branches out into other branches, that branches out into smaller branches, that might branch out to even smaller branches, that branches out into leaves. And then there's a big vein in the leaf that might branch out into other veins of the leaf. And so it might not matter as much at what spatial scale you look at the tree, it's kind of got this same branching structure. And it turns out nature is filled with this scale-free or fractal stimulation. Shankar Vedantam: What do you think the role is of these curved edges and fractals in the effects that nature is having on our minds? Marc Berman: It could be that curved edges and in particular fractalness might be easier to process. So in particular, if we think about the fractals again, because it's the same shape that's kind of repeating at different scales, you may not have to process or remember every single detail because it's repeated. But I also think, too, and we don't have all the answers to this, it might have to do with an aesthetic preference that people kind of like symmetry and this fractalness also has some symmetrical properties. People tend not to like sharp edges or straight lines as much. You can imagine some buildings that people don't enjoy very much tend to be brutalist architecture that's very rectilinear. People tend to prefer more gothic architecture that has more intricacy or you could imagine a building designed by Gaudi in Barcelona that's very curvy, that's mimicking the patterns of nature. People really seem to enjoy having curved structure in the environment. Shankar Vedantam: Now, of course, all of us have been out on a beautiful day in the woods or by a beach or in a mountainside and the weather is great and everything looks beautiful. But you found that even when nature is unpleasant, if you go out in the middle of a snowstorm and the roads are slick and the sidewalks are icy, even then nature can have benefits for us. Marc Berman: That's right. One of our major studies where we tested directed attention theory involved bringing people into the laboratory and giving them some objective cognitive task to measure their directed attention abilities. And one of these tasks was called the backwards digit span task. So participants would hear digits out loud at a pace of about one digit per second. So four, seven, three. And the participants would need to repeat those digits back in backwards order. So three, seven, four. And we kept increasing the number of digits up to nine digits.




