The little-known behavioral scientist who transformed cities all over the world

Share It



Behavioral psychologist Ingrid Gehl influenced much of the thinking of her husband, the celebrated urbanist Jan Gehl. Imagine if all designers were married to behavioral scientists–or even if they just talked with each other.


“Why are you architects not interested in people?” Ingrid Gehl asked her new husband, Jan. “What do you think about the fact that your architecture professors take their photos at four o’clock in the morning . . . without the distraction of people in the photos?”


In the early 1960s, and in many cases still today, these were forbidden questions, particularly among those we think of as designers–architects, city planners, and engineers. Then and now, designers consider human needs for health, survival, safety, and comfort through building codes and best practices. Psychological needs are only an afterthought–at best.


Ingrid, however, was no conventional designer–she was a psychologist. And by entertaining such questions, Ingrid and her husband took the first steps on a journey to create city spaces for the full range of human needs. The Danish couple’s ideas have since made life better in cities like New York, Moscow, Buenos Aires, Sydney, and London. Of course, many parts of many cities still seem optimized for buildings and cars. But the story of Ingrid and Jan is a model for what partnerships between behavioral scientists and designers can look like today.



In the early years of Ingrid and Jan’s collaboration, seeking answers to Ingrid’s questions, the new couple studied public spaces. They were among the first to do so systematically, recording details like the number of people sitting, standing, or walking in parks, streets, and squares. In one of their studies, they spent months observing old Italian cities, which they noticed “seethed with life.” One reason for the vitality of these old Italian cities, they theorized, was they “had not yet been reorganized by rational planners.” (The post-World War II trend towards “rationalist” approaches to city planning modeled cities as machines made up of buildings and roads.) As psychologists like Daniel Kahnemann and Amos Tversky exposed the limitations of mechanistic theories about human rationality, Ingrid and Jan suggested that similar flaws were holding back city design.


Jan and Ingrid shared insights from the first decade of their collaboration in two books, both published in 1971. Jan’s book was titled Life Between Buildings, and Ingrid’s was called Bo-miljø, which translates loosely as “Living Environment.” In Bo-miljø, Ingrid challenged readers to recognize the humans they were designing for. She emphasized that people need to stay healthy, comfortable, and safe, and psychologically well. And cities could help. They could meet our need for human contact, or for privacy. They could enhance how we experience life, how we share and create ideas, and how we walk, play, and stay active.


Ingrid’s perspective, which may seem obvious to behavioral scientists, should have unveiled a dangerous blind spot for architects, planners, and engineers. But Bo-miljø had limited impact, even in Denmark and even among the narrow audience of professionals for whom it was written (most of whom were not the same gender as Ingrid). Whatever the reasons, Ingrid’s book quickly went out of print and she went on to a long and distinguished career practicing child psychology, occasionally contributing to her old profession, informally, through Jan’s work.


Meanwhile, Jan’s Life Between Buildings became a planning classic and is now in its sixth edition. Through his life’s work, Jan developed the “Public Space Public Life” survey, which is used around the world to generate snapshots of city conditions, just as he and Ingrid had done in Italy. As a public intellectual, Jan has shared human-focused planning perspectives and methods with millions of people. And through his design firm, these ideas have transformed cities all over the world.



One example is Times Square in New York City. As recently as a decade ago, one of the most visited places on earth was the anti-Bo-miljø, a place where humans not in cars could only use 11% of the space in the square, even though they made up about 90% of the visitors. And yet, for conventional designers who are trained and paid to create buildings and roads, closing part of Times Square to traffic is counterintuitive.


For city leaders guided by Jan’s human-focused approach, however, closing the square to traffic was a viable option. They tested the closure temporarily. This pilot study led to fewer pollutants and pedestrian injuries, revenue increases for neighboring businesses, and, surprisingly, better traffic circulation in surrounding areas. The way forward was clear. Today, the main road through Times Square, Broadway, is permanently closed to vehicles between 42nd and 47th streets.


The new Times Square is better for these traditional measures of human health and safety. And it also better meets psychological needs. Spaces previously dominated by vehicles are now available for Bo-miljøpriorities like talking, walking, thinking, and playing.


Unfortunately, Times Square remains an exception. We can, and should, rely more on the human-focused approach. Behavioral scientists and designers who work together can create cities that make life better for the people in them.


And for the people outside of them. How we design our cities shapes life even for people who never see one. Consider climate refugees. Every year, three New York Cities worth of people have their lives upended by droughts, rising sea levels, storms, and other effects of climate change. Our current approach to city design is partially to blame. More than half of worldwide climate changing emissions can be traced to energy used for transportation and in buildings, much of which occurs in cities. Because of their density, cities do tend to reduce the environmental impact of their inhabitants, who have less space to heat and cool, shorter commutes, and more mass transportation options. But such efficiencies remain small compared to what is needed to significantly mitigate climate change.


Designing cities to reverse climate change is only possible with a mindset shift away from creating new roads, buildings, or even solar panels. Even a world covered with enough solar panels to power every building and car eventually is limited by the raw materials needed for these buildings and cars, not to mention the solar panels.


The good news is that behavioral science helps distinguish real from perceived needs by revealing how and why we don’t always want what we will like. We may assume that we want to spend our money on a fast car, big house, and manicured yard. But what we actually like may come from investing in Bo-miljø, so that we can walk places and live close to current and future friends (remember college?).


What’s more, behavioral science also encourages us to distinguish physical needs from psychological ones. Or, as Ingrid convinced Jan, to focus on “people rather than bricks.” Our psychological needs for shelter and mobility are not constrained by physical limits to buildings and roads. People move through Times Square more efficiently and enjoyably, and the redesign used fewer physical resources, not more.


Imagine if all designers were married to behavioral scientists–or even if they just talked with each other. Jan’s design impact stems from Ingrid introducing him to behavioral science: to humans and their actual versus theorized behavior; to pilot studies and systematic measurement and analysis. And by working with Jan, Ingrid magnified her influence as a behavioral scientist, shaping a future with cities that better meet human needs.


This article is authored by Leidy Klotz, an engineering and architecture professor who co-directs the Convergent Behavioral Science Initiative at the University of Virginia. This article was published in partnership with the Behavioral Scientist magazine. 


Leave A Comment