Communities do not think; people do, and all people share the same cognitive system.
Our brain receives an immense amount of information every second. If it had to analyze each object, each image, and each situation consciously from scratch, it simply would not be able to function. To solve this problem, it uses an extraordinarily efficient system: categories.
To categorize is to group different elements under the same general idea.
When we see a chair, we do not analyze whether it has four legs, three legs, wheels, or armrests. We simply think, “It’s a chair.”
When we see a tree, we do not first check the exact shape of its leaves; we recognize it almost instantly. This process happens thousands of times a day, and it works extraordinarily well most of the time.
The Brain Does Not Use Definitions
There is, however, an important detail. For a long time, it was assumed that people recognized categories through definitions.
That is to say:
“A bird is an animal with feathers, a beak, wings…”
However, cognitive psychology showed that this is not usually how it works.
What we use are prototypes, or schemas.
They are not definitions; they are mental examples.
If someone says the word “bird,” most people do not imagine an ostrich. Nor a penguin.
What usually comes to mind is a bird that sits closer to the center of our mental representation.
Human categories work around these central examples: the more something resembles the prototype, the faster we recognize it; the further it moves away, the more doubt appears.
Prototype and Definition Are Not the Same
This difference is essential for understanding many contemporary debates.
A definition tries to establish objective criteria by answering a very specific question:
What belongs to this category, and what falls outside it?
A prototype, by contrast, aims to help the brain quickly recognize what it is facing. It belongs to the realm of perception, not reasoning.
Definitions require reflection; prototypes work almost automatically. Confusing the two leads to many errors.
We can recognize something as bird-like without that meaning it is a bird. We can recognize a melody as jazz-like without claiming that it necessarily belongs to that genre.
And in the same way, we may perceive a certain arrangement of ropes as visually familiar without that, by itself, allowing us to conclude that it belongs to shibari.
Perceptual similarity is never historical proof.
What Happens When We Encounter Something New?
Whenever an unfamiliar image appears, the brain automatically compares it with the prototypes it already has. This happens even before conscious reasoning begins.
If the similarity is high, an immediate sense of familiarity arises. We think: “This reminds me of shibari.”
So far, there is no problem. In fact, that ability is one of the great achievements of human cognition: it allows us to learn, recognize patterns, and transfer knowledge across different situations.
What is truly interesting happens when the image does not fit.
The intuitive response would be to think that the brain immediately begins searching for complex explanations, but in reality the opposite is more common: it simply discards the stimulus.
From a cognitive standpoint, that is the most efficient solution. If every ambiguous object required lengthy reflection, we would live in a state of permanent paralysis.
However, precisely those ambiguous cases have enormous intellectual value, because they force us to revisit our categories and ask whether the problem lies in the object, or in the way we classify it.
Remaining in that uncertainty for a time is one of the foundations of critical thinking. Not rushing to a conclusion makes it possible to detect nuances that rapid classification tends to conceal.
When the Prototype Begins to Expand
There is another possibility: instead of discarding the new case or keeping it as an exception, the brain may slowly begin to modify its own prototype.
This process does not usually result from a single experience. Rather, when we repeatedly encounter examples that share certain traits, the mental representation of the category gradually expands. It is part of human learning.
The prototype of a “phone” that a person had in 1980 was very different from the one people have today. The category evolved because reality changed.
This is an extraordinarily useful mechanism when it responds to real changes in the world. The problem arises when that expansion is no longer guided primarily by evidence and begins to be shaped by social, identity-based, or emotional factors.
At that point, the prototype ceases to reflect only perceived reality and starts to reflect the shared narrative of a community.
When the Prototype Replaces the Definition
We all use prototypes, discard information, and learn by expanding our categories. However, certain communities display an additional tendency.
Instead of using the prototype as a recognition tool, they end up using it as though it were a definition, and this shift has profound consequences.
A definition forces us to establish limits and answer uncomfortable questions.
What actually belongs to shibari? What practices fall outside it? Which images constitute historical antecedents, and which simply present formal similarities?
Answering precisely requires accepting that some ideas, images, or practices highly valued by part of the community may not in fact belong to that category.
To define is, inevitably, to exclude, and exclusion creates tension.
The more heterogeneous a community is, the more difficult it becomes to reach an operational definition that everyone accepts. Paradoxically, that difficulty favors the survival of concepts that are broader, more ambiguous, and more elastic.
Not because they describe reality better, but because they reduce internal conflict, resulting in an inversion of the concept. It is no longer the definition that organizes the prototype.
It is the collective prototype —fed by years of images, narratives, references, and emotional associations— that ends up functioning as though it were the definition itself.
If someone asks what a bird is and different people answer “a sparrow,” “a penguin,” “an ostrich”..., we still share a relatively stable category.
But if part of the community answers “a table,” another answers “a kite,” and another “a bat,” and, to avoid conflict, no one dares to formulate a clear definition of bird anymore, the category has lost its ability to discriminate reality.
And when a category stops discriminating, any resemblance begins to seem sufficient.
That is the moment when a simple visual similarity can begin to turn, almost without anyone noticing, into a supposed historical continuity.