Simple Heuristics That Make Us Smart

(Evolution and Cognition Series)

by Gerd Gigerenzer, Peter M. Todd, and the ABC Research Group

About the Authors

Gerd Gigerenzer is Director of the Center for Adaptive Behavior and Cognition (ABC) at the Max Planck Institute for Human Development in Berlin, Germany, and a former Professor of Psychology at the University of Chicago and other institutions. He has won numerous prizes, including the AAAS Prize for Behavioral Science Research in 1992.

Peter M. Todd, co-founder of the ABC Research Group, is a research scientist at the Max Planck Institute for Human Development in Berlin, Germany. He has published numerous papers and books on modeling behavior, music, and evolution, and is an associate editor of the journals Adaptive Behavior and Animal Cognition.

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Book description

How can anyone be rational in a world where knowledge is limited, time is pressing, and deep thought is often an unattainable luxury? In our book, "Simple Heuristics That Make Us Smart," we invite readers to embark on a new journey into a land of rationality that differs from the familiar territory of cognitive science and economics. Traditional models of rationality in these fields have tended to view decision-makers as possessing supernatural powers of reason, limitless knowledge, and an eternity in which to make choices. But to understand decisions in the real world, we need a different, more psychologically plausible notion of rationality. This book provides such a view. It is about fast and frugal heuristics-simple rules for making decisions with realistic mental resources. These heuristics can enable both living organisms and artificial systems to make smart choices, judgments, and predictions by employing bounded rationality.

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.


For a detailed description of the ideas and results in our book, please see our precis (to appear with multiple reviews in Behavioral and Brain Sciences, 2000).

You can also read more about our research on simple heuristics in recent articles in:Science News ("Simple minds, smart choices," by Bruce Bower, May 29, 1999, p. 348-349; see full text)New Scientist  ("Basic instinct," by Kate Douglas, Sep. 4, 1999, p. 32-35; see a summary)

For the source data of the simulations described in the book, please see


From the Back Cover

"How do people cope in the real, complex world of confusing and overwhelming information and rapidly approaching deadlines? This important book starts a new quest for answers. Here, Gigerenzer, Todd, and their lively research group show that simple heuristics are powerful tools that do surprisingly well. The field of decision making will never be the same again."
--Donald A. Norman, Nielsen Norman Group, Professor Emeritus, University of California, San Diego, and author of "Things that Make Us Smart" and "The Invisible Computer".

"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, Nobel Laureate in Economics and Professor of Computer Science and Psychology at Carnegie Mellon University

"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, Nobel Laureate in Economics and Professor of Economics at the University of Bonn

"Gigerenzer & Todd's 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, Professor of Psychology at MIT and author of "How the Mind Works" and "Words and Rules"


More Information

You can find reviews and other information on the book´s pages at or Barnes & Noble.

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Table of Contents


Addresses of the ABC Group Members


I. The Research Agenda

1. Fast and Frugal Heuristics: The Adaptive Toolbox
Gerd Gigerenzer and Peter M. Todd

II. Ignorance-based Decision Making

2. The Recognition Heuristic: How Ignorance Makes Us Smart
Daniel G. Goldstein and Gerd Gigerenzer
3. Can Ignorance Beat the Stock Market?
Bernhard Borges, Daniel G. Goldstein, Andreas Ortmann, and Gerd Gigerenzer

III. One-reason Decision Making

4. Betting on One Good Reason: The Take The Best Heuristic
Gerd Gigerenzer and Daniel G. Goldstein
5. How Good are Simple Heuristics?
Jean Czerlinski, Gerd Gigerenzer, and Daniel G. Goldstein
6. Why Does One-reason Decision Making Work? A Case Study in Ecological Rationality
Laura Martignon and Ulrich Hoffrage
7. When Do People Use Simple Heuristics and How Can We Tell?
Jörg Rieskamp and Ulrich Hoffrage
8. Bayesian Benchmarks for Fast and Frugal Heuristics
Laura Martignon and Kathryn Laskey

IV. Beyond Choice: Memory, Estimation, and Categorization

9. Hindsight Bias: A Price Worth Paying for Fast and Frugal Memory
Ulrich Hoffrage and Ralph Hertwig
10. Quick Estimation: Letting the Environment Do the Work
Ralph Hertwig, Ulrich Hoffrage, and Laura Martignon
11. Categorization by Elimination: Using Few Cues to Choose
Patricia M. Berretty, Peter M. Todd, and Laura Martignon

V. Social Intelligence

12. How Motion Reveals Intention: Categorizing Social Interactions
Philip W. Blythe, Peter M. Todd, and Geoffrey F. Miller
13. From Pride and Prejudice to Persuasion: Satisficing in Mate Search
Peter M. Todd and Geoffrey F. Miller
14. Parental Investment By Simple Decision Rules
Jennifer Nerissa Davis and Peter M. Todd

VI. A Look Around, A Look Back, A Look Forward

15. Demons versus Heuristics in Artificial Intelligence, Behavioral Ecology, and Economics
Adam S. Goodie, Andreas Ortmann, Jennifer Nerissa Davis, Seth Bullock and Gregory M. Werner
16. What We Have Learned (So Far)
Peter M. Todd and Gerd Gigerenzer


Name Index

Subject index

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Buy the Book


Simple Heuristics That Make Us Smart
Evolution and Cognition Series
by Gerd Gigerenzer, Peter M. Todd, ABC Research Group

Oxford University Press
August 1999

432 pp.
64 line illus.
ISBN 0-19-512156-2

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