Categorically Speaking
How our brains make sense of the world around us, and why we sometimes get it wrong

If we pause to think about our situation as animals, we can see that we live in a world of nearly overwhelming complexity. As living organisms we’re surrounded by all manner of external phenomenon and many of them are important to our survival. We have five basic ways to interact with the world: touch, smell, sight, sound, and taste.
Our brains have to make sense of the inputs we get from these different sources, so right from the start our brains establish categories. We don’t expect a visual image to taste of anything, and we don’t expect to hear the warmth of the sun on our skin. Within each category our brains establish further sub-categories in order to sift and sort the incoming signals. For example, there are parts of our brain that take visual input and sort it into edges, lines (vertical, horizontal, angled), other shapes, and colors.
Without categorization, our brains wouldn’t be able to organize the signals that flood in every second and as organisms we wouldn’t be able to respond coherently to our environment. Categories are therefore extremely useful. Our brain establishes all kinds of sub-sub-sub categories in order to enable us to function in the world. So we have categories not only for sorting sensory input but also for concepts. We have categories for family, friends, acquaintances, colleagues, enemies, and so forth.
A category is a kind of conceptual box into which our brains put seemingly similar things. Unlike a physical toy-box and a set of toys, however, something can go into multiple categories. A mother can be in the category of family and also in the categories of female, older person, and also into whatever other categories may be suitable. We then establish hierarchies between categories in order to prioritize importance. So for a small child, family is usually a much more important category than older person.
Some of our categories, such as those involved with our sensory organs, are innate. Most of our categories, however, are learned. When we’re very small we often assume everything is alive: mom, teddy, rocks, trees, shiny objects. Slowly we learn that if something can move of its own volition, chances are it’s alive. Static things are more tricky: trees don’t move of their own volition but we’re told by adults that trees are also alive.
Likewise Grandfather Fred in his chair over in the corner: we’ve never seen him move but we’re told he’s alive too. We can create a special category for him: things-that-don’t-move-but-are-still-alive-if-they-don’t-smell-worse-than-usual.

Our brains, not surprisingly, also use categories to distinguish between abstractions. We have categories like truth, lie, right, and wrong and heuristics about how to place a concept into such abstract categories.
Our automatic and highly useful categorization has the consequence that we end up perceiving the world in terms of the categories we establish.

When we look at a rainbow, our brains automatically sub-divide the continuum from violet to red so that we think we’re seeing a banded arc. Children draw rainbows like this: as a series of distinct color stripes. But studies show that the way our brains segment the rainbow into distinct color bands depends on the manner in which our particular language handles color. Russian-speakers will divide the blue area into dark blue and light blue, corresponding to Russian синий and голубой whereas an English-speaker will simply have a single band of blue. And regardless of how we segment the rainbow, in reality it’s a perfectly smooth continuum of colors and not in fact a series of nicely-separated bands.
It’s easy to guess that while categories are amazingly helpful most of the time, they can also lead us astray when we encounter something that doesn’t fit neatly into one of our pre-established mental boxes. Our brain will assign the phenomenon to the “best-fit” box and in consequence we’ll make various assumptions associated with that particular category. And these assumptions will be wrong.
A classic, and indeed classical, example of such a category error is the centaur. It’s almost certain that the notion of the centaur, a mythical beast with the body of horse and the torso of a human, arose because of a category error.

Let’s pretend we’re living in a civilization that has never imagined, never mind seen, the concept of someone sitting on the back of a quadruped. As far as our brains are concerned, quadrupeds fit into the category of animals and we bipedal humans fit into the category of people. This is a very useful distinction. When we see a cat or a cow we don’t expect human-style interactions, and when we see a person we don’t expect them to run off and chase mice or rub up against our leg to mark us with their scent. Our behavior adapts to our expectations coming from our inherent categorization.
What we don’t know, however, is that over the hills and far away in a totally different tribe someone with a woeful disregard for our mental categories has had an idea: they looked at a particular quadruped and thought, “what if, instead of walking, I sat on the back of that animal?” Although it would take a bit of trial and error to perfect the technique of riding, the pay-off would be phenomenal: the ability to travel faster and further for far less personal effort.
Now this person, along with their fellow horse riders, shows up in our tribal zone.
Our brains see quadrupeds, so clearly this is some new kind of animal. We don’t have a mental category for human+animal combination. So we interpret the signals we receive from our eyes and slot this new animal into our pre-existing category: something with four legs and the torso of a human. We even give it a name: centaur.
Job done!
Eventually, however, someone dismounts from their steed and our brains are forced to accommodate the fact that we’re not looking at one animal but, somehow, in a way we don’t yet comprehend, two animals. As we increase our exposure to this strange phenomenon our brain will create a new category to accommodate it. Today, we are exposed at a very early age to pictures of people riding horses and so by the time we see the phenomenon in real life we have a category that can accommodate it easily. Thus we no longer “see” centaurs.
The situation is rather different when it comes to abstractions. If we make a category error in the way we assign an abstraction there may be no equivalent to the dismount operation that enables us to perceive our mistake. We’ll go on making the same incorrect assignment and continue to make the wrong associations, sometimes for our entire lives.
Unlike the case of the centaur, this type of category error is alive and well today and we see it nearly everywhere. Our brains are very immature with regard to the categorization of abstractions, which suggests we only began to develop this capacity sometime in the last few hundred thousand years. Our brains are very much a work in progress and our cognition very often falls through the gaps that exist in our incomplete mental structures.
Most people will, at some point in their lives, have encountered the myth of the “unlucky black cat.” The question is: given that domesticated felines have little or no influence on the course of events, how is it that our brains so readily embrace this entirely spurious idea?

If we step back a bit we can see there’s a category error problem here. We humans are adapted to operate during daylight hours; our night vision is quite poor and certainly much inferior to predators who operate during the hours of darkness. Thus we’re adapted to find somewhere relatively safe at the end of the day so we can close our eyes and sleep through the darkness and reawaken refreshed at the next dawn. Not surprisingly, being in the dark elicits a stress response within us. We can’t see what may be coming to attack us. We can’t easily co-ordinate our actions with other group members.
Operating in the dark is a bad place to be for us humans. So we’ve got a fundamental category with some important attributes: if it’s dark, it’s scary and bad.
Along comes the black cat. Sure, we slot it into our category of animal, but we also slot it into our category of dark. As it’s a dark thing it is therefore scary and malignant.
Even a modern educated person’s brain will react in the same general way: studies show that we don’t activate our stress hormones when looking at a line-drawing but when we look at a silhouette there’s a slight activation of cortisol, even though the silhouette is obviously not presenting an actual physical threat.

Our darkness category and its associations is so well-established that we expect dark things to be threats. The “black kit” of special forces (actually very dark blue) is designed to make them less visible when operating in darkness but it also serves the purpose of being far more frightening than any bright color could possibly be. Novelists darken their antagonists: the dementers in the Harry Potter novels are black wraiths. Famously, Christian mythologists used to claim that people of African descent have dark skins because this is a mark of iniquity imposed on them by an invisible magical creature first known to recorded history as the tribal cult deity El and subsequently rebranded as Yahweh, Jehovah, and eventually simply as god.
Other examples of category error can arise because of individual experience. Studies have shown that when we fear something we’re more likely to think we perceive it in the external world than is warranted by actual evidence. Post-traumatic stress victims will over-react to certain stimuli because their categorization has become skewed. For an ordinary person, hearing a child shout to a sibling may trigger various reactions depending on whether we’re the child’s parent, guardian, or stranger. But for someone with PTSD the volume alone may result in the shout being categorized as loud, with the attribute danger. And thus whereas an adult nearby merely turns to see what the child has shouted about, the PTSD victim experiences an overwhelming fight-or-flight reaction that can incapacitate them for several minutes.
By way of another example, someone who’s experiences have led them to be sexually repressed will tend to see sexual connotations in a wide range of non-sexual stimuli because their brain is dropping the wrong things into the category sexuality, where they are associated with the attribute distressing.

The Victorians were famous for being hyper-sensitized to all manner of stimuli that in reality had little or no sexual connotations whatsoever. A modern male Westerner transported back through time and dropped into Victorian London would find that a perfectly harmless inquiry to a Victorian female about where to buy under-garments would be interpreted as an overt sexual advance. Not surprisingly, the Victorian Lady would feel discomfort and anxiety and, depending on the tightness of her corset, experience respiratory distress.
But fast-forward to London of the present day and no such reaction would be likely.
Our abstract categories are largely learned, which means that education and experience are supremely important in shaping our ability to interact with the world around us in adequate ways.
One of the reasons so many of us, especially as we get older, come to resent the rapid changes of modern life is because they render some of our categories less useful.
We’re evolved to do as little mental work as possible because mental activity burns precious calories that for most of our evolutionary history were more likely to be required to power muscles. So we resent having to think, even unconsciously. External change forces us to change internally in order to adapt, and we deeply resent having this requirement imposed on us. That’s why, for as long as people have been recording their thoughts, we’ve harked back to an imaginary Golden Age when things were much better and younger people knew their place (which was: to avoid disturbing older people).
This is also why older and less intellectually sophisticated people disproportionately vote for such obvious stupidities as Brexit, Trump, Bolsonaro, Duterte, and all the other idiocies that have become so popular over the last five years. Each in its own way pretends it’s possible to return to an imaginary past that will require from us no mental effort. A past in which our existing mental categories will be adequate and thus a past where our innate desire for intellectual indolence can be fully satisfied.
Conversely, it’s obvious that when we’re willing and able to expend the effort to develop more sophisticated categorization, the less likely we will be to make gross cognitive errors. When we have several categories for color we can sub-divide the spectrum. When we have categories for quadruped and biped and biped-riding-quadruped we won’t believe we’re seeing a centaur when looking at someone on horseback. When we teach ourselves that dark things don’t necessarily represent danger, we can resist the lure of superstition.
It’s also evident from the PTSD and Victorian Lady examples above that our hierarchy of categories is somewhat malleable. Anyone who’s experienced real persistent thirst or hunger knows how the brain begins to see everything in terms of “does this contain any moisture” or “can I eat this.” Obviously this is highly adaptive, driving us to exploit to the maximum any potential environmental resources and thus permitting us to survive through exigent times.
The same malleability however can lead us into undesirable habits as well. If we’re in a society in which it’s difficult or impossible to get our intimacy needs adequately met we’re likely to over-sexualize many non-sexual things in our environment, much like the Victorian Lady above. That’s why cultures that are highly religious are rife with sexual violence and pedophilia whereas secular cultures in which sexuality is not taboo experience a much lower incidence of such harms. It’s a sure bet, therefore, that if Vladimir Putin succeeds in pushing Russia back into the medieval embrace of Russian Orthodox Church norms, already-high Russian levels of rape and child abuse will increase significantly.
It follows from everything we’ve touched on so far that the more sophisticated the categories we form in our brain, the more able we are to deal adequately with the complexities of the world in which we live. In fact a reasonable definition of intelligence is the ability to correctly categorize a phenomenon and ascribe to it the appropriate attributes.
A lack of categorical sophistication, conversely, leaves us unable to perceive important distinctions. This incapacity is exacerbated if, as is likely, we also have a poorly-developed sense of self.
Inadequate self-perception means we have to use categories such as group affiliation in order to sustain an internal representation of ourselves. Thus it is common today in the USA for less cognitively skilled people to identify as Christian Republicans, so much so that for these folk the two separate categories (Christian, Republican) have effectively merged into a single category we can term ChriRepub. As such, the attributes they associate with Christian (doing good, behaving well) are automatically assigned also to Republican.
This is why perfectly ordinary people often support acts of pure evil. For a ChriRepub, tearing a terrified infant from the arms of its mother and throwing it into a cage is an act of goodness simply because it has been done at the behest of other ChriRepubs. Conversely, as the opposite of Republican is Democrat, it logically follows for such people that whatever Democrats do must be wrong and anti-Christian.
As no one is born with this kind of category confusion it is evident that much of our cognitive structure is learned. Ideas, therefore, are supremely important in fashioning human society because they have a direct impact on the way in which our brains organize information about the outside world. If an idea can persuade us to slot one or more phenomena into a particular category, this will shape how we regard those phenomena.
We can see clear evidence of this with regard to how media organizations have responded to the rise of populism over the last few years. In the West, most reputable journalists can be categorized as lefty-trendy. These are well-meaning liberals who have consciously or unconsciously absorbed Marxist dialectic: society is shaped by the inevitable struggle between a small number of capitalists and the large number of proletariat. Hence even quite educated journalists see the world through this lens regardless of facts to the contrary. That’s why the narrative of the chattering classes has consistently claimed that the tsunami of mindless populism that has recently swept the globe is “a protest against the elite.”
Quite how a “protest against the elite” results in tens of millions of blue-collar people voting for self-proclaimed billionaires and members of the British upper class is not addressed. It’s because, lacking categorical adequacy, lefty-trendy journalists can’t accommodate some highly significant elements of the real world. Not surprisingly, their policy prescriptions to “solve” the problem are in consequence wildly misguided.
Another example, this time at the level of the individual as well as society at large, can be seen with our current dogma of Political Correctness regarding obesity. Today, 86% of US citizens are overweight. Half of all US health care spending (nearly one trillion dollars as of 2019) goes on treating totally unnecessary weight-related illnesses. The UK is nearly at the same level and obesity is now a worldwide epidemic. But we’re told that obesity isn’t primarily a health problem. No, it’s primarily a fashion choice. We’re told that “body positivity” is good and pointing out the terrible health and financial costs of obesity is “fat shaming” and thus very bad indeed.

So instead of trying to tackle a major problem that is crippling tens of millions of people we instead fixate on whether or not advertisements for items of clothing feature “normal-shaped” models.
The recognition that our thoughts depend on our internal system of categorization and hierarchy helps explain why it’s impossible to communicate with someone whose categorizations and hierarchies are significantly different from our own.
When Sally, shocked by the Trump Administration’s intentional brutalization of terrified infants, asks her dear old Auntie Mary how she can possibly vote Republican, Auntie Marie has no way to understand the question in the way Sally intends. For Auntie Marie, voting Republican is the only possible option because her internal category of ChriRepub means that she literally cannot conceive of (a) any ChriRepub performing a harmful act, and (b) any alternative way to perceive the situation. So she’ll explain that the infants weren’t really terrified at all but it was just the way the liberal media portrayed the situation, that the infants are really much better off in the cages than with parents who as illegal criminal terrorists were clearly unsuitable guardians, and all manner of other exculpatory nonsense.
Auntie Marie isn’t being intentionally obtuse or disingenuous; she simply lacks the mental capacity to accommodate the phenomenon because her system of categorization and hierarchy is too primitive to deal with real-world complexity.
The good news is the obverse of the bad news. If we can develop additional categories and develop hierarchical flexibility by means of learning through interactions with the world around us, it’s possible for us to acquire greater adequacy. We can, perhaps with significant conscious effort, begin to be aware of the categories we already have formed and extend them, supplement them, and retire them based on the degree to which they conform to real-world phenomena. We can, perhaps, begin to become aware of our ability to juggle hierarchies of categories when this is helpful for ensuring our interactions with the world are more beneficial.
Conscious development of our categories and hierarchies isn’t easy. One reason for the difficulty lies in the fact that the brain physically implements these relationships by means of weighting inter-neuronal connections. A category we’ve had for a long time and which we use regularly will be impossible to eradicate; we’ll need to augment it and extend it in order to increase its ability to deal with real-world phenomena more adequately.
And let’s face it: that’s probably the most urgent requirement facing us as a species at this point in our history. We’ve created enormous problems and we’re doing everything necessary to make each one worse and worse. Unless we can improve the ability of our ape-brains to create more adequate categories and manipulate the hierarchies in more suitable ways, we’re likely to exterminate not only ourselves but much of the other life currently sharing with us this precious and delicate Earth.