The title might quickly create skepticism in most people, and that is completely understandable. Sometimes you find surprises when you start reading or watching something with great skepticism and it ends up being actually quite interesting (it has happened to me several times). With a bit of luck, this could also be the case for most of those who watch this.
The terms 'thinking' and 'reason' were words invented a long time ago, and we often assume an unclear representation of what these two words mean. Our language still maintains many imperfections based on the deficient analyses of our ancestors about their environment. Just like the word 'miracle': a very imprecise word, invented in an attempt to explain any event that seemed too good to be earthly. Dictionaries are as old as language itself, and we can even find different definitions for the same word across different dictionaries. We often find ourselves surprised at the great irrationality that humans can reach.
Irrationality should not be a surprise; it should be something predictable and understandable.
We usually see reason as a power of the mind to create understandings of what surrounds us through certain logical mechanisms. We usually think that we depend on our intelligence to evaluate our environment, but in reality it is the environment itself that we depend on to make our conjectures. To understand reason, we can think of our mind as a computer: we can have a very powerful computer, but in the end, it will be limited by the information we input into it.
The machine, like our brain, can only work with the information it receives. If we want to edit a photo, the computer will be incapable of knowing how to do that, unless we input the information (which would be the program we introduce). But it will also be limited by that program, and it can only be as good and efficient as the program/information we input. We can put in a very deficient program, and the only thing our computer can produce will be equally deficient results, regardless of its processing capacity.
The same goes for us: no matter how powerful our brains may be, we are limited by the information we receive. If we receive deficient information, our ideas will be very deficient. This is the premise of the following video, which attempts to explain why humans cannot think or reason:
