Gerd Gigerenzer

Gigerenzer received his PhD from the University of Munich in 1977 and became a professor of psychology there the same year. In 1984 he moved to the University of Konstanz and in 1990 to the University of Salzburg. From 1992 to 1995 he was Professor of Psychology at the University of Chicago and has been the John M. Olin Distinguished Visiting Professor, School of Law at the University of Virginia. In 1995 he became director of the Max Planck Institute for Psychological Research in Munich. Since 2009 he has been director of the Harding Center for Risk Literacy in Berlin.

Gigerenzer was awarded honorary doctorates from the University of Basel[4] and the Open University of the Netherlands. He is also Batten Fellow at the Darden Business School, University of Virginia, Fellow of the Berlin-Brandenburg Academy of Sciences and the German Academy of Sciences Leopoldina, and Honorary Member of the American Academy of Arts and Sciences and the American Philosophical Society.

With Daniel Goldstein he first theorized the recognition heuristic and the take-the-best heuristic. They proved analytically conditions under which semi-ignorance (lack of recognition) can lead to better inferences than with more knowledge. These results were experimentally confirmed in many experiments, e.g., by showing that semi-ignorant people who rely on recognition are as good as or better than the Association of Tennis Professionals (ATP) Rankings and experts at predicting the outcomes of the Wimbledon tennis tournaments. Similarly, decisions by experienced experts (e.g., police, professional burglars, airport security) were found to follow the take-the-best heuristic rather than weight and add all information, while inexperienced students tend to do the latter. A third class of heuristics, Fast-And-Frugal trees, are designed for categorization and are used for instance in emergency units to predict heart attacks, and model bail decisions made by magistrates in London courts. In such cases, the risks are not knowable and professionals hence face uncertainty. To better understand the logic of Fast-And-Frugal trees and other heuristics, Gigerenzer and his colleagues use the strategy of mapping its concepts onto those of well-understood optimization theories, such as signal-detection theory.

A critic of the work of Daniel Kahneman and Amos Tversky, Gigerenzer argues that heuristics should not lead us to conceive of human thinking as riddled with irrational cognitive biases, but rather to conceive rationality as an adaptive tool that is not identical to the rules of formal logic or the probability calculus. He and his collaborators have theoretically and experimentally shown that many cognitive fallacies are better understood as adaptive responses to a world of uncertainty—such as the conjunction fallacy, the base rate fallacy, and overconfidence.[5]

The basic idea of the adaptive toolbox is that different domains of thought require different specialized cognitive mechanisms instead of one universal strategy. The analysis of the adaptive toolbox and its evolution is descriptive research with the goal of specifying the core cognitive capacities (such as recognition memory) and the heuristics that exploit these (such as the recognition heuristic).[6]

Alongside his research on heuristics, Gigerenzer investigates risk communication in situations where risks can actually be calculated or precisely estimated. He has developed an ecological approach to risk communication where the key is the match between cognition and the presentation of the information in the environment. For instance, lay people as well as professionals often have problems making Bayesian inferences, typically committing what has been called the base-rate fallacy in the cognitive illusions literature. Gigerenzer and Ulrich Hoffrage were the first to develop and test a representation called natural frequencies, which helps people make Bayesian inferences correctly without any outside help. Later it was shown that with this method, even 4th graders were able to make correct inferences. Once again, the problem is not simply in the human mind, but in the representation of the information. Gigerenzer has taught risk literacy to some 1,000 doctors in their CMU and some 50 US federal judges, and natural frequencies has now entered the vocabulary of evidence-based medicine. In recent years, medical schools around the world have begun to teach tools such as natural frequencies to help young doctors understand test results.

• Cognition as intuitive statistics (1987) with David Murray
• The Empire of Chance: How Probability Changed Science and Everyday Life (1989)
• Simple Heuristics That Make Us Smart (1999)
• Bounded Rationality: The Adaptive Toolbox (2001) with Reinhard Selten
• Reckoning with Risk: Learning to Live with Uncertainty (2002, published in the U.S. as Calculated Risks: How to Know When Numbers Deceive You)
• Gut Feelings: The Intelligence of the Unconscious (2007)
• Rationality for Mortals (2008)
• Heuristics: The Foundation of Adaptive Behavior (2011) with Ralph Hertwig & Torsten Pachur
• Risk Savvy: How to Make Good Decisions (2014)
• Simply Rational: Decision Making in the Real World (2015)