Studies of risk perception examine the judgements people make when they are asked to characterize and evaluate hazardous activities and technologies. This research aims to aid risk analysis and policy-making by providing a basis for understanding and anticipating public responses to hazards and improving the communication of risk information among lay people, technical experts, and decision-makers. This work assumes that those who promote and regulate health and safety need to understand how people think about and respond to risk. Without such understanding, well-intended policies may be ineffective.

http://science.sciencemag.org/content/sci/236/4799/280.full.pdf

Perception of risk.

A review is presented of the book “Heuristics and Biases: The Psychology of Intuitive Judgment,” edited by Thomas Gilovich, Dale Griffin, and Daniel Kahneman.

Heuristics and Biases: The Psychology of Intuitive Judgment

Perhaps the simplest and the most basic qualitative law of probability is the conjunction rule: The probability of a conjunction, P (A&B) cannot exceed the probabilities of its constituents, P (A) and P (B), because the extension (or the possibility set) of the conjunction is included in the extension of its constituents. Judgments under uncertainty, however, are often mediated by intuitive heuristics that are not bound by the conjunction rule. A conjunction can be more representative than one of its constituents, and instances of a specific category can be easier to imagine or to retrieve than instances of a more inclusive category. The representativeness and availability heuristics therefore can make a conjunction appear more probable than one of its constituents. This phenomenon is demonstrated in a variety of contexts including estimation of word frequency, personality judgment, medical prognosis, decision under risk, suspicion of criminal acts, and political forecasting. Systematic violations of the conjunction rule are observed in judgments of lay people and of experts in both between-subjects and within-subjects comparisons. Alternative interpretations of the conjunction fallacy are discussed and attempts to combat it are explored.

/pdf/extensional-versus-intuitive-reasoning-the-conjunction-2cmoy4v6op.pdf

Extensional versus intuitive reasoning: The conjunction fallacy in probability judgment.

Much research in the last two decades has demon- strated that human responses deviate from the performance deemed normative according to various models of decision mak- ing and rational judgment (e.g., the basic axioms of utility theory). This gap between the normative and the descriptive can be inter- preted as indicating systematic irrationalities in human cognition. However, four alternative interpretations preserve the assumption that human behavior and cognition is largely rational. These posit that the gap is due to (1) performance errors, (2) computational limitations, (3) the wrong norm being applied by the experi- menter, and (4) a different construal of the task by the subject. In the debates about the viability of these alternative explanations, attention has been focused too narrowly on the modal response. In a series of experiments involving most of the classic tasks in the heuristics and biases literature, we have examined the implica- tions of individual differences in performance for each of the four explanations of the normative/descriptive gap. Performance er- rors are a minor factor in the gap; computational limitations un- derlie non-normative responding on several tasks, particularly those that involve some type of cognitive decontextualization. Un- expected patterns of covariance can suggest when the wrong norm is being applied to a task or when an alternative construal of the task should be considered appropriate.

https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0140525X00003435

Individual differences in reasoning: Implications for the rationality debate?

A theory of norms and normality is presented and applied to some phenomena of emotional responses, social judgment, and conversations about causes. Norms are assumed to be constructed ad hoc by recruiting specific representations. Category norms are derived by recruiting exemplars. Specific objects or events generate their own norms by retrieval of similar experiences stored in memory or by construction of counterfactual alternatives. The normality of a stimulus is evaluated by comparing it to the norms that it evokes after the fact, rather than to precomputed expectations. Norm theory is applied in analyses of the enhanced emotional response to events that have abnormal causes, of the generation of predictions and inferences from observations of behavior, and of the role of norms in causal questions and answers. This article is concerned with category norms that represent knowledge of concepts and with stimulus norms that govern comparative judgments and designate experiences as surprising. In the tradition of adaptation level theory (Appley, 1971; Helson, 1964), the concept of norm is applied to events that range in complexity from single visual displays to social interactions. We first propose a model of an activation process that produces norms, then explore the role of norms in social cognition. The central idea of the present treatment is that norms are computed after the event rather than in advance. We sketch a supplement to the generally accepted idea that events in the stream of experience are interpreted and evaluated by consulting precomputed schemas and frames of reference. The view developed here is that each stimulus selectively recruits its own alternatives (Garner, 1962, 1970) and is interpreted in a rich context of remembered and constructed representations of what it could have been, might have been, or should have been. Thus, each event brings its own frame of reference into being. We also explore the idea that knowledge of categories (e.g., "encounters with Jim") can be derived on-line by selectively evoking stored representations of discrete episodes and exemplars. The present model assumes that a number of representations can be recruited in parallel, by either a stimulus event or an

https://www3.canyons.edu/faculty/rafterm/0%200LLI%20LOVEandLOSS/Day%206%20Files/1986%20-%20Norm%20Theory%20-%20Comparing%20Reality%20to%20Its%20Alternatives.pdf

Norm theory: Comparing reality to its alternatives

AN APPROACHED IS PRESENTED FOR ESTABLISHING A QUANTITATIVE MEASURE OF BENEFIT RELATIVE COST FOR ACCIDENTAL DEATHS ARISING FROM TECHNOLOGICAL DEVELOPMENTS IN PUBLIC USE. THE ANALYSIS IS BASED ON TWO ASSUMPTIONS: (1) HISTORICAL NATIONAL ACCIDENT RECORDS ARE ADEQUATE FOR REVEALING CONSISTENT PATTERNS OF FATALITIES IN THE PUBLIC USE OF TECHNOLOGY, AND (2) THAT SUCH HISTORICALLY REVEALED SOCIAL PREFERENCES AND COSTS ARE SUFFICIENTLY ENDURING TO PERMIT THEIR USE FOR PREDICTIVE PURPOSES. SOCIETAL ACTIVITIES FALL INTO TWO GENERAL CATEGORIES--THOSE IN WHICH THE INDIVIDUAL PARTICIPATES ON A "VOLUNTARY" BASIS AND THOSE IN WHICH THE PARTICIPATION IS "INVOLUNTARY" IMPOSED BY THE SOCIETY IN WHICH THE INDIVIDUAL LIVES. ALTHOUGH THIS STUDY IS EXPLORATORY, IT REVEALS SEVERAL INTERESTING POINTS: (1) THE INDICATIONS ARE THAT THE PUBLIC IS WILLING TO ACCEPT "VOLUNTARY" RISKS ROUGHLY 1000 TIMES GREATER THAN "INVOLUNTARY" RISKS. (2) THE STATISTICAL RISK OF DEATH FROM DISEASE APPEARS TO BE A PSYCHOLOGICAL YARDSTICK FOR ESTABLISHING THE LEVEL OF ACCEPTABILITY OF OTHER RISKS. (3) THE ACCEPTABILITY OF RISK APPEARS TO BE CRUDELY PROPORTIONAL TO THE THIRD POWER OF BENEFITS (REAL OR IMAGINED). (4) THE SOCIAL ACCEPTANCE OF RISK IS DIRECTLY INFLUENCED BY PUBLIC AWARENESS OF THE BENEFITS OF AN ACTIVITY, AS DETERMINED BY ADVERTISING, USEFULNESS, AND THE NUMBER OF PEOPLE PARTICIPATING. (5) IN A SAMPLE APPLICATION OF THESE CRITERIA TO ATOMIC POWER PLANT SAFETY, IT APPEARS THAT ENGINEERING DESIGN OBJECTIVELY DETERMINED BY ECONOMIC CRITERIA WOULD RESULT IN A DESIGN-TARGET RISK LEVEL VERY MUCH LOWER THAN THE PRESENT SOCIALLY ACCEPTED RISK FOR ELECTRIC POWER PLANTS. THIS METHODOLOGY FOR REVEALING EXISTING SOCIAL PREFERENCES AND VALUES MAY BE A MEANS OF PROVIDING THE INSIGHT IN SOCIAL BENEFIT RELATIVE TO COST THAT IS NECESSARY FOR JUDICIOUS NATIONAL DECISIONS IN NEW TECHNOLOGICAL DEVELOPMENTS. THE APPENDIX CONTAINS THE DOCUMENTATION FOR RISK BENEFIT ANALYSIS CALCULATED FOR MOTOR-VEHICLE TRAVEL, TRAVEL BY AIR ROUTE CARRIER, GENERAL AVIATION, RAILROAD TRAVEL, SKIING, HUNTING, SMOKING, VIETNAM, ELECTRIC POWER, NATURAL DISASTERS, AND DIEASES AND ACCIDENTS. /SRIS/

Chauncey Starr

Papers

Social benefit versus technological risk. what is our society willing to pay for safety