Rational Isn't Reasonable

It's rational to want a fever when you're sick. A one-degree increase in the body's temperature slows the replication rate of some viruses by a factor of 200. But it's not reasonable. Despite fevers turning on the body's immune system, we view them as bad. Why? Fevers are uncomfortable and we don't like discomfort. When you have a fever of 106 and your shivering uncontrollably, rationale goes out the window. Economists try to model out what happens to businesses based on consumer preferences. Yet they never hold true. The optimal outcome in game theory strategies rarely ever happens. This is because humans are not rational, we are reasonable. Reason is a combination of logic and emotions. It's far more useful than rationale.

We believe we're rational beings, but we're actually masters of post-decision rationalization. As Scott Adams points out, we experience a gradual awakening to this truth: first noticing irrationality in others, then reluctantly recognizing it in ourselves. Evolution didn't wire us for perfect perception of reality—just survival. While we can be rational in simple, well-defined situations (like finding the best bargain), most of life's complex decisions trigger our biases. The uncomfortable truth? Rather than being rational 90% of the time as we might assume, we're likely rational only about 10% of the time—if that. Our most confident logical explanations are often just compelling stories we tell ourselves after our unconscious mind has already decided.