What is Common sense?
Common sense is something people often use to value other people’s actions and behaviors.
Completely disregarding their behaviors.
Or rather, Common sense for them is a projection onto others as something that should be applied in all situations.
As if that would be a miracle cure.
But what is common sense?
This is the definition of “common sense” according to dictionary.cambridge.org:
“The basic level of practical knowledge and judgment that we all need to help us live in a reasonable and safe way”.
When you see the definition of the term “common sense” you might start to wonder if you are talking about “common sense” when using the term.
I bet you conclude that it is a valuation made by each person reading it and defining what basic level (a value) is for them.
You can read more about how humans value everything around them in the book "Happiness Trap” by Russ Harris. And how detrimental that is to your well-being.
That’s precisely my point.
Common sense for me is different from another person since we have different levels of the basic level of practical knowledge and we judge our surroundings differently.
The Neuropsychological perspective
Your left dogmatic and narcissistic hemisphere contains everything rational and logical.
While your right hemisphere contains your reasoning, i.e., how things implicitly stick together in patterns.
When you combine reasoning with rationality, you create common sense.
For the right hemisphere to be accessible to you.
You need to enter a relaxed state of mind.
You see this clearly in stressed, agitated, or focused people since that sedates the right reasoning hemisphere.
What is common sense in reality?
I would argue that people tend to use it in a simpler way than the definition stands for.
Therefore, making the statement “It is common sense ….......” a valuation and simplified explanation of your perception of reality.
But, bear in mind that it might not be shared by others.
Does this mean that using the term “Common sense” is a mute expression?
I would argue that it is a bad choice of wording since we are back to square one in communication.
Instead, they make decisions using the peripheral (emotional) route rather than the direct (logical) route (Elaboration Likelihood Model, ELM) that I talked about in Mental Models of Humans.
But mostly, people repeat their habits throughout their days.
Let us start with a basic level of practical knowledge.
In today’s work environment, we have different age groups working together.
If we compare me and then a millennial for the sake of the argument.
We probably have been raised differently purely practically speaking.
What might be basic practical knowledge for me might not be basic practical knowledge for a millennial.
We might just have different opinions about that.
Therefore, have different expectations about that part in the definition of “Common sense” when we talk about the same thing.
How about basic levels and judgment?
Well, my judgment on many things is completely different than others in my age group since I have different experiences with work, physics, psychology, mathematics, and cognition compared to others.
One might say that it is “Common sense” that if you put up a sign on a card swiper at the register that clearly says.
“There is no “blip” so you have to swipe and punch in the code for your credit card.
Though many stores do this people still do not see the sign 3 cm away from the screen.
You could argue that it is common sense to read the sign and not say it is broken right.
Well here is the thing.
Humans see with a focus on arm's length the size of a thumbnail.
The reason why you see the world sharp all around you is because your eyes constantly move so your perception is that everything is in focus.
But it isn't in reality.
Therefore, they do not see the sign but keep looking for the transmitting signal that is always in the middle of the screen since the person already has that mental model (brain scheme).
If another person, that never uses the card in that way, always swipes the credit card and punches in the code is trying the card swiper.
There will not be an issue since that is the mental model of that person.
So basic level and practical knowledge and judgment are different for that person compared to the one that utilizes the blip function.
But for this to work for the person with the mental model of the blip then the sign needs to be where the blip indicator usually is, 3 cm further down.
That way the person connects (Gestalt Theory - Principle of Common Region and Principle of Element Connectedness) the error message with the action it is about to perform.
This way, the person understands quickly and doesn't get upset in the process.
What about living reasonably and safely?
Well, I have a great example of this.
Where I live, I have a railway crossing for us pedestrians who want to step onto the platform when boarding the train.
The crossing has no protection besides a light that sits way above your head height and misses the line of sight for people, purely cognitively speaking.
An alarm signal that sounds even when the train stands still in 50 % of the cases.
Like in the story of the boy who cried ‘wolf’ too many times.
Next time when the train is moving I might not pay any attention to the alarm.
I have to add that I have a pair of Bose noise-cancelling headphones.
With them on I do not hear the signal and do not see the yellow light saying “STOP” (constant light) way above my head far from my line of sight.
Purely UX-design wise the crossing is dangerous.
Simply not safe.
To add to the story someone has been overrun by the train and died at the crossing.
One time last winter I was stressing to get to the train and I didn’t hear the alarm sound.
Nor did I see the yellow consistent light in the word of “STOP” high above my head.
Luckily my peripheral eyesight saved me.
I freaked out that the train was moving towards me and that I had already made my decision on going across to the other side.
I managed to intervene and abruptly stop my movement.
I got very scared and my system 2, logical system (ELM) kicked in and made a radical and permanent decision based upon my knowledge of cognitive science.
The decision was that I would never leave the home or office with headphones on my ears or around my neck because the probability of me being stressed is high.
Therefore, endangering my life.
You might say it is common sense but then again it is more than common that people walk around with noise-cancelling headphones today more than ever before.
It is common sense to look for the train, but it is not practical, in that, in this modern world we live in now looks a bit different than before smartphones and noise-canceling headphones.
It might need a different version of common sense.
This has been filmed in "City of Angels (1998)" where Meg Ryan listens to music wearing headphones and riding a bike at the same time.
She was not as lucky as me.
We must not jump to the conclusion that common sense is something we can demand from one another to expect the right outcome.
Like in the case of going “all in”.
As the definition states it requires basic judgment in that it might just differ depending on if the person uses system 1, the emotional route, or system 2, the logical and direct route when making a judgment.
I would argue that “Common sense” completely disregards how humans function and is not adequate as a term today or in dialog around a subject.
Because it completely disregards how people make judgment calls.
Humans have a way of perceiving the world cognitively.
There is little to nothing you can do to alter that.
As one example we have “Gestalt” psychology that helps you understand the visual world that is presented before you and draws conclusions in your brain to make it coherent and more efficient.
That way you can drive in bad weather even if you only follow the white lines on the center of the road.
That is your brain telling you that the line is continuous, the Law of Good Continuation or Continuity even if it is not in reality.
So, when you say using “Common Sense” you’re simply addressing what is right for “YOU” at that moment and it has nothing to do with the person that you're probably talking to or about.
I would argue that when you tell someone what common sense is.
You just might not live up to the definition of the wording.
Therefore, ending up making statements about your values and perception of "your" common sense.
Which when put in context in a dialog or discussion makes little to no sense.
Conclusion
I think I made my point by now that "Common Sense" is not the best option to use in communication.
Instead, you are better off focusing on describing "Context" in Who is saying What and When about Whom and Why.
And if you add a summary to your communication then the rate of success is likely to increase.
This way nobody needs to read between the lines and try to understand the other person’s “Common sense”.
Thus reducing the likelihood of misunderstanding.