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Biomedical subjects

A Tversky

Publications and source records attributed to A Tversky.

At least 19 recordsLinked to original sources
PubMed1996

On the belief that arthritis pain is related to the weather.

There is a widespread and strongly held belief that arthritis pain is influenced by the weather; however, scientific studies have found no consistent association. We hypothesize that this belief results, in part at least, from people's tendency to perceive patterns where none exist. We studied patients (n = 18) for more than I year and found no statistically significant associations between their arthritis pain and the weather conditions implicated by each individual. We also found that college students (n = 97) tend to perceive correlations between uncorrelated random sequences. This departure of people's intuitive notion of association from the statistical concept of association, we suggest, contributes to the belief that arthritis pain is influenced by the weather.

Arthritis, Rheumatoid↗
PubMed1996

Confidence and accuracy in trait inference: judgment by similarity.

We examined the confidence and accuracy with which people make personality trait inferences and investigate some consequences of the hypothesis that such judgments are based on similarity or conceptual relatedness. Given information concerning a target person's standing on three global personality dimensions, American and Israeli subjects were asked to estimate the target's self-ratings of 50 trait adjectives and to express their confidence by setting a 90 percent uncertainty range around each estimate. The estimates were positively correlated with the actual ratings obtained from subjects who had evaluated themselves in terms of the 50 traits, but were far too extreme. Furthermore, confidence was negatively correlated with accuracy: People's estimates were most inaccurate and made with greatest certainty when the trait in question was highly similar to the information provided as a basic for judgment. We suggest that intuitive personality judgments overestimate the coherence of the structure underlying trait constructs.

Adult↗
PubMed1996

On the reality of cognitive illusions.

The study of heuristics and biases in judgement has been criticized in several publications by G. Gigerenzer, who argues that "biases are not biases" and "heuristics are meant to explain what does not exist" (1991, p. 102). The article responds to Gigerenzer's critique and shows that it misrepresents the authors' theoretical position and ignores critical evidence. Contrary to Gigerenzer's central empirical claim, judgments of frequency--not only subjective probabilities--are susceptible to large and systematic biases. A postscript responds to Gigerenzer's (1996) reply.

Attention↗
PubMed1992

Thinking through uncertainty: nonconsequential reasoning and choice.

When thinking under uncertainty, people often do not consider appropriately each of the relevant branches of a decision tree, as required by consequentialism. As a result they sometimes violate Savage's sure-thing principle. In the Prisoner's Dilemma game, for example, many subjects compete when they know that the opponent has competed and when they know that the opponent has cooperated, but cooperate when they do not know the opponent's response. Newcomb's Problem and Wason's selection task are also interpreted as manifestations of nonconsequential decision making and reasoning. The causes and implications of such behavior, and the notion of quasi-magical thinking, are discussed.

Choice Behavior↗
PubMed1990

Differential weighting of common and distinctive components.

We investigated possible explanations of the finding that the relative weight (W) of common components in similarity judgments is higher for verbal than for pictorial stimuli. A serial presentation of stimulus components had no effect on verbal stimuli; it increased the impact of both common and distinctive components of pictorial stimuli but did not affect their relative weight. On the other hand, W was increased by manipulations that reduced the cohesiveness of composite pictures, such as separating, scrambling, and mixing their components. Furthermore, W was decreased by manipulations that enhanced the cohesiveness of composite verbal stimuli by imposing structure on their components. Verbal and pictorial representations of the same stimuli yielded no systematic differences in W.

Adult↗
PubMed1982

On the elicitation of preferences for alternative therapies.

We investigated how variations in the way information is presented to patients influence their choices between alternative therapies. Data were presented summarizing the results of surgery and radiation therapy for lung cancer to 238 ambulatory patients with different chronic medical conditions and to 491 graduate students and 424 physicians. We asked the subjects to imagine that they had lung cancer and to choose between the two therapies on the basis of both cumulative probabilities and life-expectancy data. Different groups of respondents received input data that differed only in whether or not the treatments were identified and whether the outcomes were framed in terms of the probability of living or the probability of dying. In all three populations, the attractiveness of surgery, relative to radiation therapy, was substantially greater when the treatments were identified rather than unidentified, when the information consisted of life expectancy rather than cumulative probability, and when the problem was framed in terms of the probability of living rather than in terms of the probability of dying. We suggest that an awareness of these effects among physicians and patients could help reduce bias and improve the quality of medical decision making.

Adult↗
PubMed1982

Representations of qualitative and quantitative dimensions.

Geometric representations of psychological dimensions are analyzed and compared to an alternative set-theoretical approach. Judgments of similarity between forms and figures reveal the following effects: (a) qualitative attributes are curved relative to quantitative attributes, contrary to intradimensional subtractivity; (b) quantitative attributes augment differences in qualitative attributes, contrary to interdimensional additivity; (c) adding a new dimension with a fixed value increases similarity, contrary to translation invariance. The implications of these results to multidimensional representations of proximity data are discussed.

Adolescent↗
PubMed1981

The framing of decisions and the psychology of choice.

The psychological principles that govern the perception of decision problems and the evaluation of probabilities and outcomes produce predictable shifts of preference when the same problem is framed in different ways. Reversals of preference are demonstrated in choices regarding monetary outcomes, both hypothetical and real, and in questions pertaining to the loss of human lives. The effects of frames on preferences are compared to the effects of perspectives on perceptual appearance. The dependence of preferences on the formulation of decision problems is a significant concern for the theory of rational choice.

Choice Behavior↗
PubMedDate not supplied

Reason-based choice.

This paper considers the role of reasons and arguments in the making of decisions. It is proposed that, when faced with the need to choose, decision makers often seek and construct reasons in order to resolve the conflict and justify their choice, to themselves and to others. Experiments that explore and manipulate the role of reasons are reviewed, and other decision studies are interpreted from this perspective. The role of reasons in decision making is considered as it relates to uncertainty, conflict, context effects, and normative decision rules.

Choice Behavior↗