The Psychology of Trees, with Marc Berman (Ep. 2)

Show Notes

It’s no surprise that a little nature can go a long way in making people feel better. But the research of UChicago environmental psychologist Marc Berman shows that adding trees to a city can have a significant impact on a person’s health and happiness.

Berman leads the Environmental Neuroscience Lab at UChicago, and his findings have shown that even just looking at pictures of nature or hearing nature sounds can have positive cognitive effects.

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Transcript:

Marc Berman: I think in a lot of ways, we havet designed cities, or even many built spaces in general, in ways to optimize human wellbeing and human functioning. And we think that incorporating natural elements into built spaces is a good way to do it.

Andrew Bauld: This is Marc Berman. He’s an assistant professor in the Department of Psychology at the University of Chicago. He studies how the physical environment affects the brain and human behavior, in particular, for people living in the city.

Marc Berman: Maybe if you want the outcome to be having people in the neighborhood interact more with each other, you want to have some kind of grassy plaza. If you want to reduce asthma, maybe you want to plant certain kinds of trees.

Andrew Bauld: It’s safe to say that most people recognize that a little nature can go a long way in making you feel better, but you might be surprised at just how beneficial that time in nature can be for your health and happiness.

Andrew Bauld: From the University of Chicago, this is Knowledge Applied, a podcast where we go inside the research reshaping everyday life. I’m Andrew Bauld.

Andrew Bauld: Cities. They can be loud, overwhelming, and stressful places for the people living in them.

Andrew Bauld: Feeling better now? It’s hard to argue against the relaxing nature of, well, nature, but it goes beyond just making us feel calmer. Studies have shown that a little green space can go a long way in making cities better places to live, from keeping homes cool in the summer to improving air quality, but it’s nature’s effect on a person’s mental and physical health that’s at the heart of Marc Berman’s research.

Marc Berman: I kind of always had this sense that place and the design of physical environment was impacting my behavior and then it was kind of neat to see that certain types of environment like natural environments could yield benefits.

Andrew Bauld: Marc’s studies began with a classic theory of environmental psychology called attention restoration. The idea was developed by Steve and Rachel Kaplan, psychologists at the University of Michigan who showed that people can concentrate better after spending time in nature.

Marc Berman: According to that theory, sort of humans have two kinds of attention, one being top down, directed attention, where you, as the individual person, sort of control your attentional focus.

Andrew Bauld: If you’ve ever tried to focus on a project at work or a lesson at school only to find your mind wandering, that’s because directed attention takes a lot of effort to maintain.

Marc Berman: And we’ve all had that feeling at the end of a long work day at 3:30, 4:00 where you’re kind of just staring at your computer screen and you can’t concentrate. We call that being in a directed attention fatigue state.

Andrew Bauld: The other kind of attention is involuntary, where you’re drawn to something stimulating like flashing lights or loud noises, and some of those stimulations, like the ones found in nature, can actually increase attention and reduce stress.

Marc Berman: Importantly, too, we think is how the stimulation captures involuntary attention. So walking in Times Square has lots of interesting stimulation too, but we think that kind of stimulation is very harsh. So we think it’s important that the stimulation be what we call softly fascinating like looking at a waterfall, looking at leaves being blown in the wind, and natural environments tend to have softly fascinating stimulation.

Andrew Bauld: Studies have shown you can get positive cognitive effects from just seeing pictures or movies of nature, but the effects aren’t nearly as strong as the real thing.

Marc Berman: The more artificial or levels away you get from the direct experience, the less of a benefit you get.

Andrew Bauld: So it’s going to take a little effort if you want to feel better but not to worry. Even if the weather outside is miserable, your brain won’t know the difference.

Marc Berman: You don’t have to be the biggest outdoorsy person to get the benefits. In fact, you don’t even have to like the nature experience to get the benefits.

Marc Berman: So we’ve done studies where we had people walk in nature. They walked at different times of the year. So some people walked in June, 80 degrees Fahrenheit. People loved the walk. Nice cognitive benefits. Had people walk in January, 25 degrees Fahrenheit. People came back to the labs, said, “Marc, why’d you make me go out there? I was freezing my butt off. Hated the walk.” Showed the same cognitive benefit as the people that walked in June. So you don’t necessarily have to like the nature experience to get the cognitive benefit. Something else deeper is going on.

Andrew Bauld: To try to figure out exactly what that something is, Marc and colleagues from the United States, Canada, and Australia measured the effect trees have on the residents of Toronto.

Marc Berman: We could quantify the amount of green space in different neighborhoods in Toronto with satellite imagery, but also researchers, I think, at the Forestry Department at the University of Toronto had cataloged every single tree on public land in the City of Toronto. So we had data from 580,000 trees. We also had health data from the Ontario Health Study asking people how healthy did they perceive themselves to be, but also things that were more objective. Do you have heart disease? Do you have stroke? Do you have diabetes?

Marc Berman: And what we found is we could quantify the independent effect of the trees on health, controlling for obvious confounding variables like age, education, and income.

Andrew Bauld: And what they discovered was that having just a little more nature, 10 more trees on a city block to be exact, increased how healthy residents said they felt, the same as if you gave each household on that block an extra $10,000 or made every person seven years younger.

Marc Berman: The trees seem to be having an independent effect on health, and now the question is why? What is it? Is it because it’s restoring attention, so there’s some psychological benefit that’s translating into a physical benefit? Is it because the air is cleaner? Is it because having trees on the street makes your neighborhood nicer, and people are more encouraged to exercise? Does it have to do with the bacteria of nature?

Marc Berman: So we don’t know the answer to those things yet. That’s something that we’re really interested in looking into moving forward.

Andrew Bauld: Of course, Toronto isn’t Chicago, and there’s one big difference to take into account. Canada has universal healthcare, meaning that everyone receives more or less the same care regardless of income.

Marc Berman: So maybe those economic numbers are a little bit higher in Canada than they would be in the US, but we think the relationships should still be pretty similar and so that’s what we’re trying to do now. In particular, we have similar kinds of data in Chicago. We also have similar kinds of data across the whole United States. So we’re trying to see, “Are we seeing some of the same relationships?”

Andrew Bauld: Could you ever see a situation where, say, a company realizes trees make you happier, equivalent to $10,000? Here’s some trees for your year-end bonus, rather than... is that...

Marc Berman: That’s pretty funny. I hadn’t thought about that before. Yeah, so that also brings an interesting question, too, is about choices of individual municipalities. So I can say, “Hey, Chicago, you need to plant more trees,” but the residents might say, “No, we’d prefer to have something else or spend the money on something else,” and it’s really important to take the whole picture into consideration. Although, I would say that one of the things that we’re trying to fight against is that we design cities to move goods quickly, to cram a bunch of people into a limited space. How do you design the city, design the environment to improve human wellbeing?

Andrew Bauld: Marc’s studies have focused mainly on the impact of seeing nature. But his new work is showing that even just listening to nature can work wonders.

Marc Berman: ... which may not be too surprising to people. People find listening to nature sounds quite soothing and relaxing, but we’re finding this objective attention benefit that people get after listening to nature sounds. And now, we’re doing the same thing. We’re trying to figure out what it is about nature sounds that’s producing the benefit.

Andrew Bauld: Here’s the example of the natural sound Marc plays in his research.

Andrew Bauld: And now the urban sound.

Andrew Bauld: Even just hearing those two sounds, the first one you feel almost a calm and then immediately, it’s almost like a stress of people and things around.

Marc Berman: Right. And to me, even that urban sound isn’t as stressful as we could make it. It’s not cars honking and things like that.

Marc Berman: But yes, I mean, people all have kind of a similar kind of impression to these sounds, and what we’re trying to show is that it’s not just your impression. There is some objective benefit to it.

Andrew Bauld: Marc’s new study will try and pinpoint exactly what happens when you’re watching leaves blow in the wind or you hear the sound of birds chirping by mapping people’s brains as they interact with sights and sounds from both urban and natural spaces.

Marc Berman: We have some measures for what a brain looks like when it’s working hard. And so we’re wondering even if you’re just listening to nature sounds or looking at nature images, does the brain look like it’s not working as hard compared to viewing urban images and sounds and that will also give us some identification as to whether it’s nature that’s sort of pushing you into a more rested state, urban that’s pushing you into a more fatigued state, or some combination of the two.

Marc Berman: Or is it just bringing nature to mind that’s leading to the benefits? So if we just read you nature words or primed you to think about nature, would you get the same benefits? That’s another thing that we’re kind of actively looking at. So is it something about the features, like the physical features of nature that’s producing the benefit, or is it like the thought of nature that’s producing the benefit, or is it some combination of the two?

Andrew Bauld: While his lab works to answer those questions, Marc is putting his research to use in the form of a new app called ReTUNE, which stands for Restoring Through Urban Nature Experience.

Marc Berman: The idea behind the ReTUNE app is that, let’s say you’re trying to get from Point A to Point B. And if you type this into Google, usually, it just gives you the shortest path. Well, we wondered what if we added a feature where we find you the most restorative route to get between Point A to Point B. So the most restorative route might be the route that has the most trees, the least amount of car traffic, the quietest and the safest.

Andrew Bauld: The app will be available this spring. In addition to the extensive data he’s used at the green spaces in Chicago, Marc’s goal is for users to eventually critique routes and add their own.

Marc Berman: We think we could sort of continuously tweak and improve the app based on user experience, and we’d also might learn something ourselves from a scientific standpoint. Maybe there’s some other variable that we’re not measuring that users will help point out to us that we should be measuring.

Andrew Bauld: Until the app is ready, Marc has a few suggestions for folks in Chicago looking for their own escapes in nature.

Marc Berman: Garfield Conservatory, I love. That’s just a great place. Morton Arboretum, I love. I’ll be a little bit of an advocate here. I think here in Hyde Park with Jackson Park and Washington Park in the midway, we have a lot of potential, but there’s so much car traffic, and I just think, “Man, these parks could be so awesome if we could close off some of the roads and kind of make the parks more contiguous and more self-contained and kind of be buffered from the car traffic.” I think it would really elevate those parks.

Andrew Bauld: That may be a tough sell, but the idea of opening parks and encouraging greater access to natural spaces for more people in the city is really what Marc’s research is driving towards because those benefits, they aren’t reserved just for people who can afford them.

Marc Berman: A lot of people view nature as sort of an amenity and not a necessity, that, “Yeah, if we had enough money, we could have nice parks,” or, “It’s for rich people, but we can’t afford to have it.” And we’re kind of fighting against that. We’re saying, “Actually, no, these kind of environments are actually a necessity. They’re not an amenity. And all humans kind of need these kinds of interactions.”

Andrew Bauld: Knowledge Applied is a production of the University of Chicago. To learn more, visit us at news.uchicago.edu. Subscribe to Knowledge Applied on iTunes, Stitcher, and wherever else you get your podcasts and stay tuned for our next series coming this spring. It’s called Big Brains where you’ll hear interviews with transformative thinkers changing the way you see the world.

Andrew Bauld: Thanks for listening.