We think we know what’s happening, but really we don’t

In the beginner’s mind, there are many possibilities.  In the expert’s mind, there are few.  –Shunryu Suzuki

Although we may think we know what’s going on around us, our brain is guessing.  We don’t get much input from our senses to tell us, for example, what’s physically behind us, but we have a pretty good guess that if there was a Christmas tree behind me 5 minutes ago the Christmas tree is probably still there.

I’d like to call our brain guessing about the world our “mental models.”  I have a mental model of the room that I’m in, that helps me pretend in my brain that I know what’s going on in this room, what will go on, and what has gone on.  If I can be computer-y about it, it’s like I have a function


where I can guess, based on a state (e.g. night-time, no one’s at home) that I know what’s going on in the downstairs living room, or at least the boundaries around what’s going on in that room.  (In my mental model for this room there could be cats clawing our couches, or a robber, or nothing, but there’s probably not a clown dancing.)  In a similar way of guessing what’s going on, I may have a mental model for our cat Fred:


where I can guess what our cat Fred might be doing based on what’s going on (e.g. how much food is left in the bowl, whether there’s a Christmas tree).

A few years ago, f_fredthecat(Christmas Tree) would have yielded in my brain “Fred is probably climbing the Christmas tree.”  He really liked climbing our Christmas trees and could climb two or three feet off the ground.  Now, though, he’s older, and f_fredthecat(Christmas Tree) tends to yield “I may find pine needles in the litterbox.”  My brain’s mental model for Fred f_fredthecat changed as a reflection of a change in Fred.

Minds tend to like guessing about what’s going on in the world, and I’d bet we each have hundreds of thousands of mental models.  For example right now I have mental models like…

  • f_myhomelaptopcomputer: this laptop’s plugged in and charging, its brightness is near maximum, its hard drive has plenty of space, it’s been backed up recently by Time Machine
  • f_jeans: my jeans are dry, they are comfortable
  • f_kitchensink: the kitchen sink is probably dripping right now although I can’t see it or hear it
  • f_weddingpotteryplate: the plate made by a family friend at our wedding is still balanced on our plate rail (I can see it), and even though it’s been there for several years I am still convinced it will fall soon
  • f_highchair: the high chair’s wheels are locked in place (untested)
  • f_workbuilding: Six months ago I would have thought our work building was empty.  Three months ago I went in at this time of night and saw a cadre of custodians cleaning and vacuuming, so now I’ll guess there are probably lots of people cleaning up.

All of these things are guesses–possibly very educated guesses, but they are guesses.  Although my laptop charging light is on, it is theoretically possible that power is not actually going into my computer.  (Aside: Can you tell I don’t understand how charging a battery works?)  As another example of a possibly false guess, although my jeans feel dry they could be getting wet and I haven’t noticed yet.

There are a couple of challenging things for me about mental models:

  • They are not real.  I think I know all these things, and that I know what’s going on around me, due to a small number of observations and a LOT of historical experience, reading, similar things, etc..  All of these mental models are reduced/simplified versions of reality.  The kitchen sink may have stopped dripping–it’s unlikely but possible.  The high chair’s wheels may be crawling with ants.
  • These models are unique to each person.  You may have a well developed mental model for how cakes bake in an oven.  Someone else, say a professional baker, may have another mental model.  These two expert models are probably very, very close to one another but they likely have small differences based in the different experiences of each person.  Yet we talk about “baking a cake” as if we all shared exactly the same mental model.
  • The models improve with interactions.  The more I’ve worked with something, the more experience I have, and the better understanding/guessing I can do in my mental model for the thing.  However (see next bullet)…
  • Past performance is no indicator of future results.  Just because the high chair has never exploded, does not mean it definitely will not explode.  My mental model does not account for the possibility that the high chair might explode.

The importance of first impressions

Mental models get really interesting for me when it comes to “new” things.  When I encounter something new, I search through my existing mental models to find an approximate match for the new thing.  For example, when I see a new chair, my brain searches through my mental models to find…

  • f_giantofficechair
  • f_uncomfortablechair
  • f_paddedchair
  • f_chairsthatcatssiton
  • ...

In other words, all of the different types of ways that I think chairs might work.  Then, when I sit down, I narrow down the range and eventually create a new mental model for this new chair that’s a mix of all my past experiences plus what I start to perceive.  Certainly, this is all done subconsciously, and is part of why I get surprised if the chair falls apart when I sit on it.  If that happened to me all the time, it would be part of my mental model.  Instead, if a chair fell apart when I sat on it my consciousness would wake up–“what the heck just happened?!”–and also my mental models for all chairs would change to include the possibility that the chair might fall apart.

Take all that and apply it to people.  I think that first impressions when meeting people are so important because you are sizing up the new person against all your other mental models of people.  You’re asking yourself who this new person is similar to.  This new person is “30% my eighth-grade teacher, 5% my best friend, and 65% that guy that punched me in the face.”  After more experience interacting with the person, that model would be refined, and maybe those foundational models are questioned–“oh, this person isn’t like my best friend at all”–but that mental model I’ve applied to the new person is, in my mind, actually that person, and it takes a good deal of work to realize my mental model was off.

On Guessing Effectively

So although mental models have lots of faults (such as being a poor caricature of reality although people think of them as reality), mental models are certainly useful.  They are the way our brain makes sense of the world.  I would guess that our brain has a core “function,” something like:

process_observation(observation, mental_models)

where when we observe something with one of our senses, that observation is filtered through our mental models, but then might update our mental models.  For example,

process_observation("I physically feel uncomfortable", {f_bed,...})

I feel uncomfortable laying on this bed, which reinforces my mental model about our bed, that it has an old mattress and needs to be replaced.  Or,

process_observation("I heard a squeaky noise", {f_bed,...})

if I heard a squeaky noise, I might guess it’s a bed spring popping, even if something totally different squeaked.

Basically I’m trying to say that as we hear, see, smell, taste, touch, or think things, these observations go through the filter of our mental models, but then have the chance to update or change our mental models.  We could perceive things “incorrectly” if our starting mental models are bad, or we could make poor conclusions based on how good we are at making better guesses.  All this to say, you have a big advantage if you are pretty good at updating your mental models from processing observations.  And you have a huge disadvantage if your mental models are so bad that you aren’t able to see they’re wrong and invalidate them based on observations incorrectly filtered through those bad mental models.

The better you are at guessing how things work and inferring how they work from your limited observations, questioning your mental models when they don’t make sense, the better you’ll do at approximating reality.  You will be able to make more lasting inferences and “predict the future.”  Mental models are not reality, but if you have skill at developing accurate mental models quickly then you will be “ahead” of reality getting your observations confirmed rather than running into input that contradicts what you think.

  • Chethan Pandarinath

    Are you familiar with Bayesian Inference (http://en.wikipedia.org/wiki/Bayesian_inference)? Many overlapping concepts.

    • Dang!  No, I was not.  This is really cool!! There is even something called Bayesian Brain!! “http://en.wikipedia.org/wiki/Bayesian_brain”.

      I really don’t know what I am talking about, but two comments based on the wikipedia article:
      * The set of “M” is known ?  Maybe there are things you should believe that do not appear on your radar as beliefs?
      * If applied to people, this assumes everyone has the same “learning process” for updating their beliefs