Hasty conclusions, intuition that's blind to information
The tendency to jump to conclusions on limited evidence is so important to understanding intuitive thinking that it shows up often in this book as well. I describe this tendency with the principle 'what you see is all there is.' System 1 is severely insensitive to both the quantity and quality of the information that triggers first impressions and intuitions.
Basic assessments, intuitive judgments
System 1 works differently. System 1 is constantly monitoring what is happening inside and outside the mind, and constantly evaluating various aspects of a given situation without any special intent or particular effort. These 'basic assessments' play an important role in intuitive judgments, because more difficult problems can easily be substituted with these basic assessments. This is the essential idea behind problem-solving via heuristics and biases. The fact that one judgment can be substituted for another in this way is possible thanks to two features of System 1.
One is its ability to compare and convert values across different dimensions, and the other is its ability to automatically support, including basic assessments and various other computations, whenever System 2 sets out to answer a particular question or evaluate the properties of a particular situation.
