Rationality and Reasoning

by Jonathan St. B.T. Evans

This book addresses an apparent paradox in the psychology of thinking. On the one hand, human beings are a highly successful species. On the other, intelligent adults are known to exhibit numerous errors and biases in laboratory studies of reasoning and decision making. There has been much debate among both philosophers and psychologists about the implications of such studies for human rationality. The authors argue that this debate is marked by a confusion between two distinct notions: (a) personal rationality (rationality1
Evans and Over argue that people have a high degree of rationality1 but only a limited capacity for rationality2. The book re-interprets the psychological literature on reasoning and decision making, showing that many normative errors, by abstract standards, reflect the operation of processes that would normally help to achieve ordinary goals. Topics discussed include relevance effects in reasoning and decision making, the influence of prior beliefs on thinking, and the argument that apparently non-logical reasoning can reflect efficient decision making. The authors also discuss the problem of deductive competence - whether people have it, and what mechanism can account for it.
As the book progresses, increasing emphasis is given to the authors' dual process theory of thinking, in which a distinction between tacit and explicit cognitive systems is developed. It is argued that much of human capacity for rationality1 is invested in tacit cognitive processes, which reflect both innate mechanisms and biologically constrained learning. However, the authors go on to argue that human beings also possess an explicit thinking system, which underlies their unique - if limited - capacity to be rational.

192 pages, Hardcover

First published June 1, 1996

Reviews

[G · Rating 5 out of 5]

Great book. The human mind is nowadays understood as dual. That is, our individual mind is not one single mind, it rather behaves like two distinct minds. One mind might be intuitive, the other might be reflective. The former might be automatic, the latter might be controlled. The key feature of this view is quite controversial: most of our mind’s work is implicit, heuristic, intuitive, and automatic. Moreover, our introspective registry -i.e. our stream of consciousness- seems to be a confabulation, an invention that has only a weak connection to what really happens deep in our brain. In other words, we live in a fantasy. A complex and believable fantasy, but not a reliable record. Our mind mostly lies. We lie to ourselves. This book by Jonathan ST. B. T. Evans and David E. Over is a classic in the field of cognitive science since its publication in 1996. The specific theory of the intuitive-reflective duality is clearly explained. More recently, a couple of research papers on this view recovered the main ideas of this book. A comprehensive perspective on dual-process theories was published during 2013 in Perspectives on Psychological Science by the same authors (Volume 8, Issue 3). It seems that working memory load is the criterion that differentiates between the two minds. Intuition does not load working memory, but reflection does heavily load such mental architecture. In other words, mental decoupling is highly demanding, while associative cognition works automatically. Convergent and divergent experimental evidence concerned with such distinction is thoroughly discussed in this book. In my opinion, this is a very good introduction to one of the most influential theories of the human mind. By the way, the development of a psychological theory derived from Evans’ dual view to account for decision making drove Daniel Kahneman to the 2002 Nobel Prize in Economics. One last comment: What can these theories tell about literature? In which mind does literature grow? I think that a plausible answer might be quite complex, but automatic processes may have more relevance than we think.