Reference:: R: Thinking Fast and Slow by Daniel Kahneman
Here I offer a perspective that helps understand how we reason.
In very short: we choose ease over truth.
The first and most important concept is that our brain wants to save energy at all costs. If it can spend less, it probably will. Hence, our brain will mostly strive for what's easiest, simplest, and most efficient. (Related to TK P: Ability (Fogg Behavioral Model))
Btw., the word understand is very interesting. Under stand. Stand under. It implies first principles thinking. Something that is underneath, something that creates and supports, etc. In order to understand something, you need to know its foundation on which it can stand.
The second concept is that our brain is a network of neurons concentrated in a sphere. And each concept or idea is a cluster of related neurons. When you think about a concept, a particular "pocket" of neurons lightens up somewhere in your brain.
The third concept is that our brain is a storytelling machine that can't help but jump to conclusions. It takes whatever information it has available at the time and makes the best possible story out of it, telling you very little about the information it doesn't have (Kahneman called it WYSIATI).
Why do we always create stories and jump to solutions? Is it because in order to survive we must act? If we didn't we would be dead?
Combine these three notions and you'll see that your brain will give priority to neurons that are most easily available and related—either fresh in our attention (salience), at a short distance to each other (proximity), or in big clusters (size) and then create a coherent story out of them—suppressing everything else. Because of that—and that's scary—it'll tell you not what's more true but what's more coherent (this is why biases happen).
Relates to R: Decisive by Chip and Dan Heath to limiting the number of options.
Think of it this way. You'd be more likely to notice objects that either someone pointed at, were close to you, or were large, right? If these were the only objects available—because you'd be born on a tiny island—you'd base your whole worldview on only the objects that exist on this island, being oblivious to beliefs that exist in the rest of the world.
Let's take them one by one.
Salience. When you have a fresh and strong memory, the area where the memory exists will be prioritized. Hence, the following thoughts will be 'colored' or influenced or biased by this fresh memory. Because extending beyond this highlighted area takes more energy than staying within it. Once I wanted to buy new sneakers and was considering either Air Force 1 or Jordans. I was doing quite extensive research. From that day, everywhere I go I notice other people wearing these shoes. It's not like people have suddenly started wearing them but because my brain is more easily noticing them. In short, what's focal is important.
Familiarity bias, availability bias, spotlight effect,
More on salience here: PN: What is focal is important
Proximity. Knowing that our brain prioritizes energy when one of the areas of our brain is highlighted—like when you think about a red car—you will be more likely to think about concepts that lay close to that highlighted area and are therefore related, even if these concepts aren't most relevant to your problem. A freshly-highlighted area gets a primacy and therefore colors all following thoughts (french music -> french wine)
I wrote about this here as well: P: To persuade prime networks associated with your goal
Size. Beliefs are nothing more than strong, established, mature areas of your brain that are being used frequently. Your brain will of course prioritize these areas even if it isn't true/relevant. Why? Because it has already spent so much energy to create this area so abandoning it—creating an opposing belief—would mean that all that energy would go to waste.
confirmation bias, cognitive dissonance
Relevant notes (PN: )/questions (Q:):
P: The first times are disproportionally powerful (anchoring): the first time sets a precedent in your brain—a new pocket—that changes for ever the structure of your brain.
P: To persuade prime networks associated with your goal: seeing the minds in the perspective described in this note can help understand why persuasion works.