Did you know humans have as many as 33 senses!? Taste isn't just about the "tongue": The science of senses is fascinating, even explaining why tomato juice tastes better on airplanes.

Did you know humans have as many as 33 senses!? Taste isn't just about the "tongue": The science of senses is fascinating, even explaining why tomato juice tastes better on airplanes.

"Humans have five senses"—this phrase is so familiar in both school and everyday conversation. Sight, hearing, smell, taste, and touch. It's certainly convenient and intuitive. However, recent discussions easily transcend this framework. "We might be using not just five senses, but over 20, or even 33 in some cases." What would you think if you heard such a statement? Would you be surprised? Skeptical? Or would you find yourself agreeing, thinking, "Now that you mention it, it makes sense"?


An article featured on ScienceDaily (provided by The Conversation) points out that the organization of "five senses" has become too restrictive for modern sensory research. Our bodies do not process the world solely through our eyes and ears. Even when staring at a screen, we continuously receive a vast array of signals such as muscle tension, body tilt, breathing depth, stomach condition, body temperature, and the feel of clothing against our skin. Moreover, these are not separate alarms but blend together to form a "single experience."


Why "five senses" are insufficient: We always feel in a "mixed" way

The keyword in sensory research is "multisensory." Real-world perception is closer to an ensemble where multiple senses intertwine simultaneously, rather than independent channels for each sense. A good example is the "deliciousness" of food; much of what we perceive as "taste" does not conclude with the taste buds on our tongues. The aroma that rises when we chew passes through the back of the nose, and integrates with the temperature, viscosity, texture, and chewiness in the mouth to become "flavor." In other words, taste is not a solitary king but a collaborative creation with smell and touch.


The article's intrigue lies beyond this point. For example, scent can sometimes "rewrite" touch. A story is introduced where a shampoo with a certain fragrance made hair feel more "silky," even with the same formulation. Rather than the friction coefficient of the hair actually changing, the scent intervenes in the evaluation of touch, guiding the brain to "feel that way." Here, we see that senses, while seemingly separate, actually interact with each other.


Furthermore, even low-fat yogurt can feel "richer" depending on the design of its scent. In food development, the battle is already being fought not just with calories and ingredients but with the design of scent, viscosity, and sound (chewing sound) as part of the "experience design." The division of the five senses is too crude to explain such sensory experiences in the field.


What exactly increases in the "22 to 33 senses"?

When you hear "33 senses," you might imagine a supernatural "sixth sense," but the reality is more body-oriented. The article lists at least the following senses as examples.

  • Proprioception: The sense of knowing where your arms and legs are even with your eyes closed.

  • Vestibular sense: Uses the inner ear mechanism to detect body tilt and acceleration. It is also connected with vision and proprioception.

  • Interoception: The sense of feeling changes within the body, such as heartbeat, hunger, and breathlessness.

  • Sense of agency: The "sense of self" that you are moving your own limbs.

  • Sense of body ownership: The feeling that "this arm is mine." It can be disrupted by conditions like a stroke.


The important point here is that the "added senses" are not newly introduced magic but functions that were inherently present in the body but did not fit into the "five senses folder." While the five senses are excellent as an entry point for explanation, they omit too much as a specification of the human body.


Seeing with the eyes, yet the inner ear "tilts" the scenery

One of the striking examples introduced in the article is the illusion experienced in an airplane. Looking down the aisle on the ground versus during takeoff and ascent. Optically, there shouldn't be much difference, yet during ascent, the "nose of the plane seems to rise." This is because the information on acceleration and tilt felt by the inner ear mixes with vision to create the experience of "seeing it that way." In other words, vision does not stand alone with the eyes. The act of "seeing" is constructed by the entire body.


Similarly, exhibitions and experiments report that "changing the sound of footsteps can make the body feel lighter (or heavier)." Even though your body weight hasn't changed, auditory cues interfere with the judgment of bodily sensations, altering how the body feels. At this point, the very definition of "what is a sense?" begins to waver.


Why is it difficult to count "how many" senses there are in the first place?

The expression "33 senses" is catchy but can also lead to misunderstandings. This is because the number can easily increase or decrease depending on how "sense" is defined. Even touch can quickly multiply if you count pressure, vibration, temperature, pain, and itch separately. For taste, whether you narrow it down to the basic tastes like "sweet, salty..." or include oral touch and smell as part of the "taste experience" changes the count.


This ambiguity is also well pointed out on social media.


SNS Reactions: Coexistence of Excitement and Criticism

 

This topic is easy to find amusing. However, at the same time, it is also easy to criticize for "vague definitions." Looking at discussions on Reddit, you can see both sides.


For example, in anthropology communities, there are calm observations that "the way of counting can easily become arbitrary." One comment suggests that the discussion leans towards "maximalism (wanting to count as many as possible)" and raises the issue that "classification of senses" can change depending on culture and history.

 
On the other hand, in the same thread, there are also harsh reactions like "the content is thin compared to the headline" and "it looks like AI-generated text," indicating a wariness towards sensational headlines.


In another science community, the discussion leans more towards the "philosophy of organization." While there are doubts like "aren't they just combining existing senses and giving them new names?" there are also voices supporting the importance of interoception, stating, "It's true that we sense internal signals like blood pressure and carbon dioxide levels that are hard to consciously perceive."


And in media articles (Popular Mechanics), the estimate of "22 to 33" is explained with specific examples like proprioception, kinesthetic sense, interoception, and sense of body ownership, bridging the gap for the general public by showing that there are indeed areas that cannot be fully explained by the "five senses."


Overall, the reactions on social media seem to fall into three types.

  1. Those who purely find it interesting: "Was my sensitivity a feature?"

  2. Those strict about definitions: "It's a discussion on the 'taxonomy' of senses, and inflating the numbers is dangerous."

  3. Those wary of the writing and headlines: "Isn't the basis weak for a headline meant to go viral?"


This tripartite division occurs because the topic is directly connected to "experience." While everyone feels they can verify it with their own body, the boundaries of technical terms are vague, making it easy for selective interpretation or exaggeration to creep in.


How the "33 senses" debate might change our lives

If we don't let this topic end as mere trivia, the point is more about "design philosophy" than "number." Senses work not as a list of separate organs but as an integrated system—this perspective resonates across various fields.

  • Food and Beverage: Taste changes with aroma, mouthfeel, and ambient sound. There's room to increase satisfaction even with reduced salt or fat.

  • Product Design: Texture, appearance, sound, and scent create a "sense of quality." The competition for experiential value does not occur with a single sense.

  • VR/AR and Entertainment: High-definition visuals alone do not complete "immersion." Without aligning body tilt and weight perception, discomfort and motion sickness can occur.

  • Medical and Rehabilitation: Sense of agency and body ownership, when impaired, can disrupt life. Designing to "heal" or "supplement" senses requires more than the five-sense model.


Ultimately, the question "How many senses do you have?" is not a quiz with a single correct answer. Rather, it is a question that reminds us of how complex an integrated system we are weaving the world into.


The five senses are a convenient map. But a map is not the territory itself. Scent changes touch, sound changes body weight, and the inner ear determines the tilt of the scenery. Thinking this way, what we perceive as "reality" might be more of an "edited version" created by our bodies as a whole rather than the world right in front of us.


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