Focusing on “Researchers’ Big Picture,” this series explores the future societies they envision through their work. How does their research intersect with our lives? Their visions might provide valuable insight into the path ahead for all of us.
Everyone perceives beauty and comfort differently. Kansei Design—the field of Professor Yanagisawa’s research —aims to find commonalities among diverse human perceptions and apply them through engineering to benefit society. We asked him to explore what kind of society awaits us beyond the integration of emotion and engineering.
Interviewing:
Affiliation:Professor, Graduate School of Engineering, The University of Tokyo
Name: Hideyoshi Yanagisawa
Unlocking the Power of the Handwritten Letter Through the Lens of ‘Kansei Design’.
▶︎You focus on human sensitivity from an engineering perspective and conducts research under ‘Kansei Design’. What kind of academic field is this?
Kansei (sensitivity) refers to an intuitive mental function, such as feeling that a flower blooming by the roadside is beautiful. Just recently, one publisher sent me a handwritten letter requesting me to write a book. I decided to accept because I felt a strong passion overflowing from their letter. If the request had come via email, I might have declined it This emotional response—how the same message, when handwritten, moved my heart so differently—is another perfect example of how Kansei works.
While Kansei has primarily been studied and scientifically analyzed within the field of psychology, my research in ‘Kansei Design’ takes a different path. While we draw upon psychology, we aim to translate the Kansei into mathematical equations using an engineering approach. Ultimately, ‘Kansei Design’ is a discipline dedicated to applying these insights to the design of products and services, enriching people’s lives and hearts.
▶︎While we live in an efficiency/performance-driven age, what is the emotional richness that ‘Kansei Design’ aims for?
Up until now, society has relentlessly pursued efficiency and convenience in products and services, constantly striving for functional improvements—making things lighter, faster, and more powerful. However, as ICT and AI become even more ubiquitous, functional differences will begin to fade. When that happens, user desires will naturally shift toward usability. Ultimately, we will reach a point where people seek emotional fulfillment: ‘How will this make me feel when I use it?’
This is exactly why Kansei—whether we feel comfort or a sense of attachment when interacting with a product or service—becomes a crucial factor. If we can use ‘Kansei Design’ to create products and systems that truly resonate with Kansei, users can achieve a state of inner fulfillment and live emotionally rich lives. True well-being means that both our bodies and our hearts remain in a sustained, flourishing state. Through ‘Kansei Design’ , my ultimate goal is to realize a society that supports and maintains this true state of well-being.
Designing Products and Services with Quantified Kansei
▶︎It’s surprising to learn that ‘Kansei’ can actually be quantified through math. How does this mathematical approach translate into real-world product and service design?
Before answering your question, I’d like you to try a quick, simple experiment. Would you pick up these two weights?
This is an experience called the ‘size-weight illusion.’ In reality, these two weights are exactly the same weight. However, research shows that about 99% of people perceive the smaller one to be heavier. Why does this happen? It’s because the brain unconsciously predicts that the larger object will be heavier based on its visual size. When you lift and compare them, a gap forms between the weight your brain anticipated and the actual weight you feel. As a result, you end up feeling that the larger one ‘isn’t as heavy as I thought,’ while the smaller one ‘is surprisingly heavy for its size.’ That is why the smaller weight feels heavier.
Source：Mathematical modeling of perception with focus on expectation effect and cross-modality
By analyzing various illusion phenomena, we discovered that a distinct pattern emerges in the sensory biases caused by this gap between prediction and perception. Categorizing these patterns led us to a principle known as ‘Assimilation and Contrast.’ When the prediction error is small and things feel exactly as expected, it is called ‘assimilation.’ Conversely, when the error is large and you feel a stark gap because something was different from what you anticipated, it is called ‘contrast.’ Humans perceive this error as a sense of surprise. When we simulate this ‘assimilation and contrast’ using the mathematical model of Kansei that we developed and plot it, the result looks like this.
Source：A computational model of perceptual expectation effect based on neural coding principles
This principle of ‘assimilation and contrast’ serves as a scale to measure Kansei. In my daily research, my ultimate goal is to uncover these fundamental laws—the Principia—that can act as universal metrics for human experience.
As ‘assimilation and contrast’ occurs not just in our sense of touch, but across all five senses—including sight and taste—this scale for Kansei holds incredible potential for a wide range of fields. For example, if applied to the auditory field, it becomes possible to design a sound that was felt as annoying into a pleasant tone. Taking a vacuum cleaner as an example, if you strengthen the motor to increase suction power, the suction noise gets louder. If sound-absorbing materials are used to suppress it, the body becomes larger, and manufacturing costs also inflate. Therefore, by using pleasant sound design to craft the suction noise into a comfortable sound, sound-absorbing materials can be kept to a minimum, realizing compact size and cost reduction. The possibilities extend far beyond acoustics. We can design dumbbells that visually appear lighter, allowing for high training effectiveness without changing the number of lifts . We can also shape food products to enhance the perception of sweetness to develop new health foods, or by altering the color of food, it becomes possible to add flavor variations to space food, which tends to be monotonous.
Circulating Goods and Insights: The Next-Generation Value Exchange Platform.
▶︎That sounds incredibly exciting! Earlier, you mentioned aiming for a society where people can maintain well-being, but I understood that this does not mean the development of products and services itself. How do you envision bringing that kind of society to life?
Well-being refers to a state where a person’s body and mind remain in good health and fulfillment. However, I believe that a truly well-being society is achieved only when such individuals do not exist in isolation, but instead connect with one another. One of the experimental activities we are carrying out toward realizing such social well-being is ShareWel, a web platform created within the University of Tokyo for transferring unused second-hand items.
While a major goal of ShareWel is to circulate unused items and make effective use of resources, it has another important purpose: to foster a ‘circulation of wisdom’ that expands the perspective of everyone who participates. By ‘wisdom’ here, I don’t mean mere textbook knowledge, but rather the practical insights gained through experience. For example, over time, a user might develop unique tricks or hacks with a piece of lab equipment that aren’t found in the instruction manual—such as discovering that a certain tweak makes it perform better, or finding a completely new application for it. This is what I call wisdom.
If this wisdom is passed down along with the item itself, the recipient gains something far greater than just the standard functional value of the price or the simple satisfaction of acquiring a secondhand good. As both objects and wisdom flow from person to person in a continuous chain, human connections naturally deepen and expand, ultimately shaping a truly well-being society.
▶︎It seems too good to keep this platform limited to University of Tokyo alone. Are you also considering incorporating it into other services?
If we can integrate this ‘circulation of wisdom’ into a platform like Mercari, for example, it could evolve into something far beyond a mere marketplace for buying and selling goods. Furthermore, I believe it would be incredible if we could pass down not just the wisdom embedded in an object, but also its history—the story behind it.
Imagine a wooden desk listed on Mercari. On its own, it’s just a regular, secondhand desk that someone used. But what if it were actually ‘the very desk where a Nobel prize-winning professor spent night after night developing groundbreaking ideas’? That is the power of a story. Even for the exact same desk, different owners and different uses generate completely different narratives. While people generally assume that value resides inherently within the physical object itself, that is not the case. True value comes from recognizing the information wrapped around it—the user’s wisdom and the stories the object has lived through.
If platforms like ShareWel and Mercari can serve as spaces where these elements are shared, they will transform into systems capable of delivering entirely new value while simultaneously reducing environmental impact.
From Material Abundance to Emotional Fulfillment: The Changing Faces of People and Society
▶︎Once products and services embedded with ‘Kansei Design’ become fully integrated into our daily lives, what kind of future society do you envision as your ultimate ideal?
The economist E. F. Schumacher advocated the idea of ‘Small is Beautiful’—the philosophy that an ideal economy is one that achieves maximum happiness with minimum consumption. I feel that this idea could mark a shift away from the 20th-century model of mass production and mass consumption—where economic growth measured by GDP or GNP expansion was seen as the metric of prosperity—and I personally resonate with this “Small is Beautiful” philosophy.
When ‘Kansei Design’ is implemented in products and services and the semantic value perceived by people is integrated, society will likely shift from today’s heavy bias toward material wealth to one that can rationally evaluate spiritual and emotional value. In such a society, people will have the mental leeway to cherish the deep emotional connections felt in things like handwritten letters, leading a life with a well-balanced mix of material and spiritual richness. This is my ideal.
▶︎When that society becomes a reality, how will it transform the way people live and think?
In this future society, status will no longer be found in constantly upgrading to the latest products. Instead, value will reside in how creatively we can utilize a single object and what kind of meaning we can derive from it. This closely mirrors Abraham Maslow’s concept of ‘self-actualization’—the realm where individuals fulfill their unique potential and live authentically. Going even further, the primary source of joy will shift toward inheriting the history of an object and the passion of its creator. Shopping will transcend a mere financial transaction. By immersing themselves in pure joy that goes beyond profit and efficiency, individuals will reach a state of ‘self-transcendence’—a more creative and multi-perspective way of being.
It is beyond this personal transformation that my vision for the future truly takes shape. I envision a society where achieving efficiency is no longer the ultimate goal. Instead, it will be a place where everyone can thoroughly enjoy the very process of expanding their own awareness, wondering, ‘How could I make this even more interesting?’ or ‘Why is it designed this way?’ Products and services embedded with ‘Kansei Design’ possess the power to do more than just offer convenience; they invite people into this journey of exploration. To me, a state where lifelong intellectual curiosity is continuously nourished is the true hallmark of a well-being society. Bridging individual curiosity with collective well-being, and providing a logical foundation for emotional richness through the real-world implementation of ‘Kansei Design’ —this is the future I imagine.
▶︎Through this interview, I was reminded of the importance of possessing a sensitivity that allows us to feel something is good without quite knowing why—especially today, when convenient products and services are everywhere, and we can get what we need without deep thought. When ‘Kansei Design’ permeates society, it is not hard to imagine that a harmonious society will await us—one where people and people, as well as people and things, coexist with rich creativity, allowing us to enjoy emotional happiness while obtaining functional and efficient convenience.
I look forward to seeing how Prof. Yanagisawa’s research will spread in the future. Thanks to his clear explanations of sensory concepts paired with real-life experiences, I was able to gain a deep understanding while truly enjoying the conversation.
Thank you so much for your time today.
Value Exchange Engineering PR, Kawanaka