The role of representation in Bayesian reasoning: Correcting common misconceptions

The terms nested sets, partitive frequencies, inside-outside view, and dual processes add little but confusion to our original analysis (Gigerenzer & Hoffrage 1995; 1999). The idea of nested set was introduced because of an oversight; it simply rephrases two of our equations. Representation in terms of chances, in contrast, is a novel contribution yet consistent with our computational analysis - it uses exactly the same numbers as natural frequencies. We show that non-Bayesian reasoning in children, laypeople, and physicians follows multiple rules rather than a general-purpose associative process in a vaguely specified "System 1.” It is unclear what the theory in "dual process theory” is: Unless the two processes are defined, this distinction can account post hoc for almost everything. In contrast, an ecological view of cognition helps to explain how insight is elicited from the outside (the external representation of information) and, more generally, how cognitive strategies match with environmental structure

From washing hands to washing consciences and polishing reputations

While Lee and Schwartz (in press) propose grounded procedures of separation as an explanation for physical cleansing in various domains (e.g., washing one’s hands), we suggest that separation can also account for behavioral cleansing aimed at washing consciences and polishing reputations. We discuss this extension in terms of degrees of behavioral cleansing, motivations and intentions behind cleansing, and social settings

Processes models, environmental analyses, and cognitive architectures: Quo vadis quantum probability theory?

A lot of research in cognition and decision making suffers from a lack of formalism. The quantum probability program could help to improve this situation, but we wonder whether it would provide even more added value if its presumed focus on outcome models were complemented by process models that are, ideally, informed by ecological analyses and integrated into cognitive architecture

(Italian translation: Le consulenze sull' AIDS per persone a basso rischio. In <i>La dimensione cognitiva dell' errore in medicina,<i/> pp. 185-203, by V. Crupi, G. Gensini, & M. Motterlini, Eds., 2006, Milan: Franco Angeli)

This study addresses the counselling of heterosexual men with low-risk behaviour who, voluntarily or involuntarily, take an HIV test. If such a man tests positive, the chance that he is infected can be as low as 50%. We study what information counsellors communicate to clients concerning the meaning of a positive test and whether they communicate this information in a way the client can understand. To get realistic data, one of us visited as a client 20 public health centers in Germany to take 20 counselling sessions and HIV tests. A majority of the counsellors explained that false positives do not occur, and half of the counsellors told the client that if he tests positive, it is 100% certain that he is infected with the virus. Counsellors communicated numerical information in terms of probabilities rather than absolute frequencies, became confused, and were inconsistent. Based on experimental evidence, we propose a simple method that counsellors can learn to communicate risks in a more effective way

Chapter 18 The winds of change

The ongoing process of digitalization seems to be changing our world dramatically. While many of these changes might lead to improvements for human well-being, others might entail profoundly disastrous consequences both for individuals and for societies as a whole. One research program that might be particularly suitable for studying environmental changes is the fast-and-frugal heuristics framework. This theoretical framework adopts an ecological perspective on human behavior, cognition, and performance. In an uncertain world, humans, so the argument goes, can adaptively respond to environmental demands by relying on a repertoire of simple decision strategies, called heuristics. Selecting heuristics that fit the environment results in adaptive behavior. This chapter focuses on the possible negative aspects of digitalization to discuss how the science of heuristic decision making under uncertainty might aid reflection on how individuals navigate their way through sudden, disruptive, and thorough environmental changes. Specifically, it sketches out what aversive future digital environments might look like, and which heuristics individuals and societies might rely upon in order to manage those aversive environments. The chapter concludes by (1) pointing to a series of research questions about how digital environments might differ from other environments that we humans have encountered both in our more recent history and over the course of our evolution, as well as (2) turning to questions about children and education

Communicating with Patients about Harms and Risks

Health professionals, says Herxheimer, must share their understanding of the benefits and harms of any treatment with patients and their familie

Ethical Blindness

Many models of (un)ethical decision making assume that people decide rationally and are in principle able to evaluate their decisions from a moral point of view. However, people might behave unethically without being aware of it. They are ethically blind. Adopting a sensemaking approach, we argue that ethical blindness results from a complex interplay between individual sensemaking activities and context factor