Simple Heuristics That Make Us Smart

“Gigerenzer & Todds volume represents a major advance in our understanding of human reasoning, with many genuinely new ideas on how people think and an impressive body of data to back them up. Simple Heuristics is indispensable for cognitive psychologists, economists, and anyone else interested in reason and rationality.”–Steven Pinker, author of How the Mind Works and Words and Rules

“In the past few years, the theory of rational (sensible) human behavior has broken loose from the illusory and empirically unsupported notion that deciding rationally means maximizing expected utility. Research has learned to take seriously and study empirically how real human beings … actually address the vast complexities of the world they inhabit. Simple Heuristics … offers a fascinating introduction to this revolution in cognitive science, striking a great blow for sanity in the approach to human rationality.”–Herbert A. Simon, Carnegie Mellon University, and Nobel Laureate in Economics

“This book is a major contribution to the theory of bounded rationality. It illustrates that the surprising efficiency of fast and simple procedures is due to their fit with the structure of the environment in which they are used. The emphasis on this ecological rationality is an advance in a promising and already fruitful new direction of research.”–Reinhard Selten, Professor of Economics at the University of Bonn, and Nobel Laureate in Economics

“The underlying argument of the book is that the environments in which we evolved and in which we now live have certain regularities, and that decision making mechanisms–both evolved mechanisms, and the mechanisms that we actually use today–take advantage of these environmental regularities. Most of the book illustrates this argument by showing that in many circumstances shortcut decision making mechanisms (the ‘simple heuristics’ of the title) are remarkably accurate…This book by Gigerenzer and his associates marks a significant advance in the analysis.” — Paul H. Rubin, Journal of Bioeconomics, Vol 2, 2000

“Gigerenzer et al. take on a heroic effort of creating a grand theory of mind …”–Contemporary Psychology, APA Review of Books

But when and how can such fast and frugal heuristics work? What heuristics are in the mind’s “adaptive toolbox,” and what building blocks compose them? Can judgments based simply on a single reason be as accurate as those based on many reasons? Could having less knowledge even lead to systematically better predictions than having more knowledge? We explore these questions by developing computational models of heuristics and testing them through theoretical analysis and practical experiments with people. We show how fast and frugal heuristics can yield adaptive decisions in situations as varied as choosing a mate, dividing resources among offspring, predicting high-school drop-out rates, and profiting from the stock market.

We have worked to create an interdisciplinary book that is both useful and engaging and will appeal to a wide audience. It is intended for readers interested in cognitive psychology, evolutionary psychology, and cognitive science, as well as in economics and artificial intelligence. We hope that it will also inspire anyone who simply wants to make good decisions.