Why call them System 1 and System 2 rather than the more descriptive “automatic system” and “effortful system”? The reason is simple: “Automatic system” takes longer to say than “System 1” and therefore takes more space in your working memory. This matters, because anything that occupies your working memory reduces your ability to think. You should treat “System 1” and “System 2” as nicknames, like Bob and Joe, identifying characters that you will get to know over the course of this book. The fictitious systems make it easier for me to think about judgment and choice, and will make it easier for you to understand what I say.
SPEAKING OF SYSTEM 1 AND SYSTEM 2
“He had an impression, but some of his impressions are illusions.”
“This was a pure System 1 response. She reacted to the threat before she recognized it.”
“This is your System 1 talking. Slow down and let your System 2 take control.”
Reprinted from Thinking, Fast and Slow by Daniel Kahneman, published by Farrar, Straus and Giroux, LLC. Copyright © 2011 by Daniel Kahneman. All rights reserved.