The Undoing Project is not a novel, but instead, the book provides a non-fiction, analytical account of the birth of behavior economics, a kind of middle way between psychoanalysis and economic theory. The story follows the rise and decline of a tremendous friendship between Amos Tversky and Daniel Kahneman. Their goals were to use behavioral psychology to determine clues into the mind that might have economic implications. Primarily, the looked at the lapses in judgment that are commonly found among humans, especially their inability to understand their own motivation because of false beliefs, emotional burdens or other kinds of cognitive dissonances.
For starters, the duo published studies showing that humans are not nearly as logical as we believe ourselves to be. In fact, humans are sometimes capricious, and highly influenced by external forces. In other words, we are sensitive and emotional before we are rational, and even though in our mind, the ideas feel fully formed and perfectly logical, almost no part of the human mind can be said to be perfectly logical.
This heuristic study, or motivation study, depended greatly on influencing test subjects through small experiments, such as providing them different information and then asking the test group and the control group to qualify something related to that information, and what they discovered through these tests was that people were indeed influenced in their behavior by a surprising amount of factors.
The market implications of this are that people fundamentally misunderstand their own motivations, and the advertising implications are that companies could hypothetically study these lapses in judgment to exploit them for business purposes. In other words, it represents the first attempt to use psychology as a market tool.