Marshmallow Challenge 2.0: can you actually “prototype”​ a thought?

Think of these components: spaghetti, marshmallow, tape, string, 18 minutes and a bunch of highly-focused people sitting, standing, screaming, laughing, hopefully not crying. If you are familiar with design thinking methods, you might instantly recognize these as part of a well-known quick-prototyping experiment known as the Marshmallow challenge.

The idea behind the challenge that became popular following Tom Wujec’s 2010 TED Talk, is simple: teams of four or five have to build the tallest free-standing structure out of 20 sticks of spaghetti, one meter of tape, one meter of string and a marshmallow. The marshmallow has to be on top. And, though it seems really simple, it’s actually pretty hard because it forces people to collaborate and try out all possible solutions.

The main reason why it is better known as a marshmallow challenge, and not as a spaghetti challenge, is that this little queen of softness (marshmallow) has an important role to play in nurturing higher-order thinking in participants. Marshmallow represents the fragile nature of human judgement and assumptions: we are very quick to judge others based on appearances and physical factors, and as a result we pay the price when making flawed business or personal decisions. In physical terms, the marshmallow is not as light weight and insignificant as we might be tempted to think (compared to spaghetti, for that matter). When it joins the spaghetti tower, the marshmallow has the final word to say and it decides whether the structure would stand or fall.

Statistically, children are much better at building stable structures compared to average adults. It is believed that kids take marshmallow more seriously (don’t ask me why) and for them it’s not as insignificant as to most of us. The Marshmallow challenge reminds us that in order for a project to be a success, we need to identify the assumptions we are making in the project and test these early on and often.

The moment I first tried this activity in 2015 with my university class, I got instantly hooked by its potential to help students to hone both communication and higher-order thinking skills. So, I played with the Marshmallow challenge rules quite a bit and after some tweaking, I thought that students could also be asked to create a MEANINGFUL structure, NOT necessarily the tallest or free-standing one.

If you are interested in detailed instructions, check this article, and simply replace “the tallest, free-standing structure” with “meaningful structure based on your understanding of the problem or concept at hand”.


After some initial confusion, my students picked up on the idea and began working on their meaningful masterpieces. Having conducted over sixty of such sessions, I have learned a few lessons as to how to make this experience insightful and memorable. Indeed, many of my students easily recalled it, even after several years since the experiment.

Thus, the lessons for facilitators:

Lesson#1: participants apparently need not to be restrained by time. To be thoughtful they have to talk and pull together many ideas. From my experience, 40 minutes is an average finishing time for “the meaningful structure”, though expect that some teams might finish it in 10 or even 5 minutes, depending on the complexity of their concept. If that happens, I ask these champions of thought to go and join other teams and become observers (i.e. let them compare and contrast different modes of ideation). This time does not include discussions / presentations.

Lesson#2: The making of a meaningful Marshmallow structure should be powered by a meaningful topic or experience. For the former, I assign the class an article on a controversial topic. To save time for more fun in class, it pays off if the actual reading is done outside class hours. If you are struggling to find controversial topics, is a great place to start.

When it comes to prior experience, here’s one idea I tried recently and students loved it. I assigned a task of taking a 40-minutes walk around a campus with a partner (and with all digital distractions switched off) and searching for ONE earlier unnoticed problem or issue that if solved could help hundreds of other students to thrive in their studying and improve the quality of their life. They came back… refreshed and with a bunch of real-world problems on campus. This also turned out to be an unexpected mindfulness exercise.

When it comes to creating a meaningful structure, I ask students to stop searching for possible solutions (because the goal is to prototype a thought, not a solution), so instead I requested them to ask higher-order thinking questions, such as Why this problem hasn’t yet been solved? Why should we care about it? What do people feel when they face this issue? and so on. You may have noticed some bits of empathy training here and there.

Lesson#3: This is my favorite one – let them know that actually there are no rules. Well, there is only one “rule” which is “Be noisy, talk a lot but don’t hurt your team members’ feelings”.

Lesson #4: Let them be kids and have fun. Because children somehow intuitively know that life is full of its own “marshmallows”.

Final thoughts:

These days we hear a lot about the importance of the so-called “skills of the future” that would help us distinguish us (the humans) from them (intelligent machines). Some authors suggested that nurturing of the “4C Skills” (Critical thinking, Creative thinking, Communication and Collaboration) at our schools and workplaces is one way to do this. So, I was contemplating if activities such as Meaningful Marshmallow challenge could help the educators and learners to nurture these skills.

As the saying goes, picture is worth a thousand words, so I put a few images and remarks below from the latest of such projects conducted at the University of Tsukuba.

This structure is titled “ACCESS”. Students wanted to describe a problem of in-campus transportation. Super-large campuses (such as Univ. of Tsukuba) can be a blessing and a curse, especially if you only have 15 mins to get from one class in Zone A to another class in Zone B. Students wanted to show that Marshmallow at the center represents a goal (learning, attendance, etc) and different lengths of spaghetti straws symbolize the distance and students trying to make it in time (On a more philosophical level, I thought these spaghettis could also imply the varying magnitude of problems that every student faces while trying to get “higher-educated”).

This structure is called “Not-So-Smart Phones”. Here, students wanted to emphasize the problem of obsessive smartphone use by younger adults in Japan. Three horizontal lines of spaghetti look like an “internet network” transmitting excellent signals. Hedgehog-looking object represents a divided attention and constant distractions (spaghetti) and a marshmallow in the middle represents the instant gratification that accompanies long hours of YouTubing and Instagramming.

The heart structure above and below is called “The Kindness Class”. Students wondered what would change if universities offered “Emotional Intelligence” courses in which students could actually learn the actual life-lessons?