Priors: Mental Models

I use 'Mental models' as a shorthand term for the idea that the way a single human mind comprehends reality, is not reality...

Priors: Mental Models

I use “Mental models” as a shorthand term for the idea that the way a single human mind comprehends reality, is not reality. It is the distinction that the way we think about something is not the totality of that thing.

The saying “The map is not the territory” is the most common expression of this idea. Why is it important to note this distinction? If we forget the distinction, we end up thinking that our perception of reality is actually reality. The negative consequence of letting that replacement happen is we lose touch with reality, and as conditions and circumstances change, we fail to adjust our thinking and actions to our context.

Why can’t we know the totality of a thing or reality itself?

Knowing the totality of a thing, or reality itself requires omniscience: total knowledge and understanding over time. Human cognition currently seems ill-equipped for such a task. ;) sly wink

Limited sensory ability

To start with, our senses provide us with an assortment of limited inputs. Our cognitive processes transform these disparate streams into an astoundingly impressive illusion. Take our vision for example. A simple mental model of our vision imagines it to be like a camera, scanning the outside world and capturing everything it sees, pixel for pixel. The reality is that we can only actively see a tiny part of our field of vision at any time, and our brains are otherwise generating a cohesive view of the world (see this entry on Visual Perception for more detail).

We are essentially perceiving only a tiny part of everything around us. Meanwhile, our brain is predicting everything else in our sensory field, trying to make a coherent scene out of it all. At this extreme, our brain is creating a mental model of the reality that is all around us. It is built up on thousands of hours of observation and experimentation as infants: dropping our spoons from our high chairs; standing; falling; making noises that echo off walls; grasping any object placed in our tiny hands. We inherit a bunch of our initial stimuli responses from our genetics but largely we learn them as we transition from being a tiny zygote in the womb, into a proto-consciousness and beyond. We tend to take it for granted, that each of us has developed this rich and detailed model of reality. It is truly a marvel if one looks closely.

Does ‘objective’ reality exist?

‘Objective’ reality is mediated by our mental model of it. Strictly speaking, that is not very objective at all. Does objective reality exist then? I posit that, functionally, yes it does exist. Without diving off the metaphysical or spiritual deep-ends, we come into this existence as a sensing/thinking/feeling entity, tumbling around in a chaotic mess of sensory inputs, and we consistently unpickle that mess into understandings about the physical world, language, human interactions, abstract concepts and much more. Of course, once we start layering in language, social interactions and abstract concepts, we start proliferating all sorts of mental models to make sense of the inter-subjective part of our existence.

While language can help us share abstract mental models, like the concept of a divine spirit, a nation-state, or a company, that homo sapien super-power is not sufficient to overcome the perceptual barrier between our cognition and objective reality.

What are the practical outcomes of thinking in ‘mental models’?


  • Acknowledging that even strongly held concepts about the world are only partial representations; inaccurate in some way we can’t see.
  • Acknowledging that any model of the world is going to be some sort of simplification of what is going on.


  • While these factors mean that we accept that all models are wrong, we can also determine that some models are more ‘useful’ than others.
  • We see two means of understanding the usefulness of a model: Korzybski links usefulness to the model having a ‘similar structure’ to reality, thus allowing us to make predictions and acts upon it. Harari stated a related case for thinking of usefulness as power; how much power could be derived from a model of reality?


  • Being able to consciously switch into thinking about a situation with a different mental model; that of the person standing in front of you, of a different political belief, of different school of thought. (Of course, we must acknowledge that there are mental models we hold that we cannot shake and that we might not know which or what they are.)
  • Getting a more holistic view of a situation by looking at it with several mental models.