Swiss scientist ‘delighted’ at Ig Nobel win for research on pedestrian habits

Claudio Feliciani from Ticino is one of the co-winners of the 2021 Ig Nobel Prize in kinetics. Claudio Feliciani

A Swiss researcher working in Japan is the co-winner of the humourous Ig Nobel Prize for research looking at why pedestrians run into each other. Claudio Feliciani says it’s an honour to have won (really!) and explains what he found out from studying collisions at crosswalks.  

This content was published on September 10, 2021 - 15:33

Science is not always serious. Every now and then it can make you laugh, and then reflect. This is the principle to which the United-States-based scientific and humorous journal Improbable ResearchExternal link adheres every year to select the winners of the Ig Nobel Prize, awarded to the most bizarre scientific, technical and medical achievements, based either on the research methodology or on the results obtained.

In 1995, the Ig Nobel for psychology was awarded to a group of Japanese scientists for their success in teaching pigeons to distinguish between Picasso and Monet paintings. Last year, Zimbabwe's ten-trillion-dollar prize (worth just a few Swiss francs) went to a group of researchers who sought a relationship between a nation's economic well-being and the custom of French kissing.

The prize has also landed in Switzerland, several times, in different categories. The 2008 Ig Nobel Peace Prize went to the Swiss Federal Ethics Committee for Non-Human Biotechnology and to the citizens of Switzerland for adopting the legal principle that plants have dignity (I hope the philodendron in my living room will never find out).

And the following year, a group of scientists from the University of Bern was awarded the prize for determining whether it is better to be hit in the head with an empty beer bottle or a full one.

Swiss-Italian scientist Claudio Feliciani was part of a winning team of researchers which were awarded the 31st Annual Ig Nobel for Kinetics on September 9th. The team led by Japanese scientist Hisashi Murakami focused on understanding "why some pedestrians collide with other pedestrians”. Meanwhile, the Physics prize was awarded to a team who researched the exact opposite theme of “why pedestrians DO NOT continuously collide with other pedestrian”.

Feliciani, is a researcher at the University of Tokyo and comes from the Swiss canton of Ticino.

SWI spoke with Claudio Feliciani shortly after the announcement to see what he thinks of the “honour”.

Hisashi Murakami, lead author of the study that won the Ig Nobel 2021 Prize for kinetics. Claudio Feliciani

SWI May I say congratulations? Is winning the Ig Nobel a source of pride for a scientist or is it more like a joke?

Claudio Feliciani: I'm delighted. And, from what I know, in the scientific field it is an honour. Perhaps that’s not obvious to those who are not part of this world, but besides making people laugh, there is a very serious side [to the prize]. Generally the studies that win an Ig Nobel are published by scientific journals with an excellent reputation and fellow scientists know that in most cases the study makes you laugh, but it is not trivial, even if at first glance it may seem so.

Before giving the award, [the committee] called us to make sure we weren’t offended. So I guess every now and then someone gets angry. But that wasn't the case for us;  on the contrary.

SWI: Was it a surprise?

C.F: Yes, I didn't expect it at all. I am currently doing a study in social psychology, so outside of my usual field of study. I focus on the phenomenon of sexual passivity in Japan, so people who lose interest in relationships and sex. With urban planners, a sexologist and a psychologist, we are trying to understand if this phenomenon is related to the living conditions of Japanese cities with high population density.

I told them that ours is a study that could also aspire to the Ig Nobel Prize and that I would do anything to win it. Little did I know that I had already won it for another paper [on pedestrian research] for which I would not have expected it at all. Renowned media outlets like the New York Times had covered the pedestrian research in March. But I am happier about the Ig Nobel.

SWI: Is the way the Ig Nobel committee describes your research correct ? Was it about making pedestrians collide and seeing what happened?

C.F: Let's say it's a bit of a stretch, but it's not technically incorrect. Pedestrians did not really collide in our research. It would be more accurate to say that we discovered the mechanism that leads to pedestrian collisions.

Officially, the study is concerned with understanding what mechanisms at the individual level contribute to the creation of self-organising structures at the collective level.

Not far from the campus of Tokyo University, the Shibuya crossing gives food for thought for those studying the movement of crowds. Keystone / Kimimasa Mayama

SWI: So what does the experiment consist of?

C.F: It involves observing two groups of people walking in the so-called bidirectional flow, such as crossing each other from opposite directions, as happens for example in a pedestrian crossing when the green light goes off .

Individuals tend to follow the person is in front of them and in this way, lines of people form  spontaneously. We have tried to understand the mechanism that makes them form and we have created conditions that make this spontaneous organisation more difficult.

Specifically, we caused some of the pedestrians to be distracted, asking them to walk while solving simple calculations on their phones. With just three out of 54 people focused on something else, rows formed much less quickly, especially if the distracted people were at the front of the group. And the increased attention of the non-distractors isn't enough to make up for the lack of attention of the three who are distracted. [The first part of the video below shows the formation of rows without distracted pedestrians, while the second part (from 00:22) shows distracted pedestrians at the head of the group].

We have found that a form of nonverbal and mutual communication is required for a crowd to move smoothly.

In short, it is important for two people on a collision course to anticipate each other's movements to avoid collision, while at the same time communicating their intentions.

The conclusion may seem trivial, and that could be why we won. It is obvious that if one person is distracted, they are more likely to collide with someone else. And it's obvious that if there are people looking at their phones it will take longer to get things done.

But really, the implications are quite interesting [for fields like self-driving cars or robotics .

SWI: What are those implications?

C.F: There could be some in the area of self-driving cars or robotics, for example. Some researchers are trying to create robots that can move in a crowd and act as assistants, for example, for elderly people who go shopping, by helping them and following them in  daily traffic.

Obviously, to work they must not crash into people, they must move smoothly without creating more problems than they solve.

Most people think that  these robots are just boxes full of a lot of sensors that measure distances, temperatures and so on to make them adapt to the environment.

But without an effective way to communicate their intentions and perceive those of others, robots will always be a moving obstacle.  

The same is true for self-driving cars. In situations where they have to move slowly through crowds, the most precise sensors are not enough. You have to make sure they demonstrate a clear intention, otherwise traffic risks becoming less fluid.

Talk about chance! This photo shows Claudio Feliciani (right) with Alessandro Corbetta at the TGF2019 conference in Spain. Corbetta is the lead author of the other pedestrian research that won the Ig Nobel for physics this year. Studying people colliding brings people together, it seems. The two are currently working together on another project. Granular Lab, University of Navarra, Spain.

SWI: What are the next steps?

C.F: From our experiment, we realised that people in a two-way flow pedestrian situation exchange implicit messages to let others know which direction they want to move in. However, it is still not completely clear how this message is communicated.

It could be eye movement, or the position the body takes. To figure that out, we've started using goggles that track people's eye movements in our experiments.  We hope to find an answer.

The 2021 Ig Nobel Prize Winners

Susanne Schötz for analyzing variations in purring, chirping, chattering, trilling, tweedling, murmuring, meowing, moaning, squeaking, hissing, yowling, howling, growling, and other modes of cat–human communication.

Leila Satari, Alba Guillén, Àngela Vidal-Verdú, and Manuel Porcar, for using genetic analysis to identify the different species of bacteria that reside in wads of discarded chewing gum stuck on pavements in various countries.

Jörg Wicker, Nicolas Krauter, Bettina Derstroff, Christof Stönner, Efstratios Bourtsoukidis, Achim Edtbauer, Jochen Wulf, Thomas Klüpfel, Stefan Kramer, and Jonathan Williams, for chemically analyzing the air inside movie theaters, to test whether the odors produced by an audience reliably indicate the levels of violence, sex, antisocial behavior, drug use, and bad language in the movie the audience is watching.

Pavlo Blavatskyy, for discovering that the obesity of a country’s politicians may be a good indicator of that country’s corruption.

Olcay Cem Bulut, Dare Oladokun, Burkard Lippert, and Ralph Hohenberger, for demonstrating that sexual orgasms can be as effective as decongestant medicines at improving nasal breathing.

Ethan Beseris, Steven Naleway, and David Carrier, for testing the hypothesis that humans evolved beards to protect themselves from punches to the face.

Alessandro Corbetta, Jasper Meeusen, Chung-min Lee, Roberto Benzi, and Federico Toschi, for conducting experiments to learn why pedestrians do not constantly collide with other pedestrians.

Hisashi Murakami, Claudio Feliciani, Yuta Nishiyama, and Katsuhiro Nishinari, for conducting experiments to learn why pedestrians do sometimes collide with other pedestrians.

John Mulrennan, Jr., Roger Grothaus, Charles Hammond, and Jay Lamdin, for their research study “A New Method of Cockroach Control on Submarines”.

Robin Radcliffe, Mark Jago, Peter Morkel, Estelle Morkel, Pierre du Preez, Piet Beytell, Birgit Kotting, Bakker Manuel, Jan Hendrik du Preez, Michele Miller, Julia Felippe, Stephen Parry, and Robin Gleed, for determining by experiment whether it is safer to transport an airborne rhinoceros upside-down.

Source: Improbable scienceExternal link

End of insertion

Articles in this story

Comments under this article have been turned off. You can find an overview of ongoing debates with our journalists here. Please join us!

If you want to start a conversation about a topic raised in this article or want to report factual errors, email us at

Share this story

Join the conversation!

With a SWI account, you have the opportunity to contribute on our website.

You can Login or register here.