Challenges..............................

     Historians of science have often noted that at any give time scholars in a particular field tend to share basic assumptions about there subject.  Social scientists are no exception:  they rely on a view of human nature that provides the background of most discussions of specific behaviors but is rarely questioned.  Social scientists in the 1970s accepted two ideas about human nature.  First, people are generally rational, and their thinking is normally sound.  Second, emotions such as fear, affection, and hatred explain most of the occasions on which people depart from rationality.  Our article challenged both assumptions without discussing them directly.  We document systematic errors in the thinking of normal people, and we traced those errors to the design of the machinery of cognition rather than to the corruption of thought by emotion.

-Daniel Kahneman, from his introduction to Thinking, Fast and Slowly.  The article he refers to was one of his first joint papers with Amos Tversky