Claudia González-Vallejo

Making trade-offs: A probabilistic and context-sensitive model of choice behavior.

The stochastic difference model assumes that decision makers trade normalized attribute value differences when making choices. The model is stochastic, with choice probabilities depending on the normalized difference variable, d, and a decision threshold, delta. The decision threshold indexes a persons sensitivity to attribute value differences and is a free estimated parameter of the model. Depending on the choice context, a person may be more or less sensitive to attribute value differences, and hence delta may be used to measure context effects. With proportional difference used as the normalization, the proportional difference model (PD) was tested with 9 data sets, including published data (e.g., J. L. Myers, M. M. Suydam, & B. Gambino, 1965; A. Tversky, 1969). The model accounted for individual and group data well and described violations of stochastic dominance, independence, and weak and strong stochastic transitivity.

Save Angels Perhaps: A Critical Examination of Unconscious Thought Theory and the Deliberation-Without-Attention Effect

Based on Unconscious Thought Theory (UTT) and a series of experimental and correlational studies, Dijksterhuis and his colleagues conclude that when making complex choices/decisions, conscious thought—deliberation while attention is directed at the problem—leads to poorer choices/decisions than “unconscious thought”—deliberation in the absence of conscious attention directed at the problem. UTT comprises six principles said to apply to decision making, impression formation, attitude formation and change, problem solving, and creativity. Because the implications of UTT for psychological research and theory are considerable, the authors critically examined these six principles (and the studies used to support them) in light of the extant scholarship on unconscious processes, memory, attention, and social cognition. Our examination reveals that UTT is a theory of the unconscious that fails to take into account important work in cognitive psychology, particularly in the judgment and decision making area. Moreover, established literatures in social psychology that contradict fundamental tenets of UTT and its empirical basis are ignored. The authors conclude that theoretical and experimental deficiencies undermine the claims of the superiority of unconscious thinking as portrayed by UTT.

Effects of probability mode on preference reversal

Six analysts estimated verbally and numerically the chances that specific events will occur. Sixty decision makers used each type of estimate to make binary-choice decisions and to bid for lotteries based on the events. The usual reversal of preference between choice and bidding procedures was found in the numerical condition, but the frequency of preference reversals was significantly reduced in the verbal condition. This reduction occurred because risk aversion was reduced in choice when verbal estimates were given, whereas bidding was unaffected by presentation mode. The pattern of results was predicted by and supports the hypothesis that the relative importance given to the dimensions of a prospect depends on the form in which the information is displayed.

Do decision quality and preference order depend on whether probabilities are verbal or numerical

A surprising but common finding is that decision-making performance seems, on average, unaffected by whether decisions are based on probability phrases or on numerical probabilities. This study, however, shows that on a trial-bytrial basis, preferences change as a function of how gamble probabilities are represented. Decision makers rank ordered positively valued gambles whose probabilities were another individuals verbal or numerical chance estimates of specific events

Does Choosing a Treatment Depend on Making a Diagnosis? US and French Physicians’ Decision Making about Acute Otitis Media

Background . The classic sequential processing model of clinical decision making—in which the treatment choice follows and depends on the diagnostic judgment—may in some cases be replaced by a processing model in which the treatment choice depends on an independent assessment of the diagnostic and other cues. The aim of this study was to determine which processing model would better describe physicians’ treatment choices in a simulated clinical task. Methods . Seventy-five US and French primary care physicians were presented twice, in a different order, with the same set of 46 scenarios of 15-month-old children suspected of having acute otitis media (AOM). They rated in one set the probability of AOM and in the other set whether they would treat the child with antibiotics (and how confident they felt in their decision). Linear regression analyses revealed the individuals’ 2 judgment policies. Hierarchical discriminant analysis was used to analyze the variance explained in the treatment choice by, 1st, the diagnostic judgment, 2nd, the cues specific to treatment, and 3rd, the cues specific to diagnosis. Results . Even when choosing treatment, the participants placed greatest weight on diagnostic cues, especially the ear findings. Only 28% used the cues that reflected parental issues. For 36%, the diagnostic cues had an effect on the treatment choice independent of the effect (if any) of the diagnostic judgment. Conclusion . In deciding how to treat AOM, the majority of the participating US and French primary care physicians followed the classic sequential processing model, but a substantial minority used instead an independent processing model.

Temporal Discounting in Heroin-Dependent Patients: No Sign Effect, Weaker Magnitude Effect, and the Relationship With Inhibitory Control

Impulsive behavior in heroin-dependent individuals and matched smokers was studied within the framework of temporal discounting. Two well-known effects were examined: the sign and magnitude effects (Kirby, 1997). The study also investigated the relationship between cognitive impulsivity and inhibitory control as measured by a Go/No-go task. Fifty-six heroin-dependent patients in the postmethadone treatment stage and an equal number of matched daily smokers participated in the study. The heroin-dependent patients showed higher discount rates in both gain and loss conditions. They also showed no sign effect by demonstrating similar discount rates in gains and losses. Heroin-dependent patients also exhibited a magnitude effect, which was weaker than that observed in smokers. Differential relationships between impulsivity and inhibitory control were found in the two groups. For smokers, decision-making and inhibitory control behaviors pertained to different psychological processes, whereas for heroin-dependent patients, the two behaviors were partially related. Finally, a significant correlation between length of heroin use and temporal discounting with small magnitude was found. The present study advances our understanding of the specific behavioral impulsive patterns in heroin-dependent individuals.

Brand Promotions as a Lottery

This paper shows that imprecisely stated discounts in brand promotions offered in the form of a low-probability lottery can lead to higher sales (purchase intentions) and consequently profits than equally costly conventional promotions offering a precise discount on the entire stock. Results from two different experimental studies support our findings. For high-probability lottery-like promotions, imprecise discounts lead to a lower performance for the brand than conventional promotions. We attempt to explain the findings by drawing on the behavioral decision theory literature.

Evaluation of breakfast cereals with the current nutrition facts panel (NFP) and the Food and Drug Administration's NFP proposal.

OBJECTIVE To compare judgements of nutrition and judgement accuracy when evaluating cereals with the current US Food and Drug Administration (FDA) nutrition facts panel (NFP) and two new proposed NFP based on FDA guidelines. DESIGN A between-subjects design randomly assigned participants to three NFP conditions (current NFP label and two modified NFP based on FDA proposals). Participants viewed breakfast cereals, and rated each on nutritional quality and on the likelihood of purchasing and consuming it. Participants provided demographic information and responses to questionnaires assessing nutrition/obesity knowledge, concern for healthy eating and nutrient importance. SETTING USA. SUBJECTS Two hundred and thirteen adults who completed an online survey (66·2 % female, mean age 37·31 (sd 12·56) years). RESULTS Judged nutrition quality of cereals was positively correlated with protein, fibre and potassium and negatively correlated with sugars and sodium. This pattern appeared when using the current NFP or the modified versions. Highlighted nutrients in modified NFP formats did not affect their perceived importance. Accuracy of the nutrition quality judgements was measured in relationship to an objectively defined nutrition score, NuVal®. Nutrition judgement accuracy was highest under the current NFP (Spearmans ρ=0·76 for the current NFP; 0·64 and 0·72 for the other formats). Regression analysis showed that nutrition judgement accuracy increased significantly (adjusted R 2=0·13) with obesity knowledge (β=0·27), age (β=0·15) and current NFP (β=0·13). CONCLUSIONS The current NFP is equally or more effective in conveying nutritional information compared with NFP formats based on the FDA proposal.

Assessment of calibration for reconstructed eye-witness memories

Two experiments examined confidence judgments associated with eyewitness memory for events to misinformation [Loftus, E. F. (1975). Leading questions and the eyewitness report. Cognitive Psychology, 7, 560-572]. Participants in each experiment watched videos depicting crimes and either responded to questionnaires (Experiment 1) or read narratives (Experiment 2) containing veridical or non-veridical information. Upon testing for memory performance 24h later, participants exposed to misinformation accepted the misinformation as part of their memory of the events in the videos. In both experiments, confidence judgments of participants subjected to misinformation were high and comparable to those of participants not subjected to misinformation. The relationship between accurate responding and confidence was assessed via calibration analysis [Yates, J. F. (1990). Judgments and decision making. Englewood Cliffs, NJ: Prentice Hall]. Performance on various measures of calibration was generally better for participants who were not exposed to misinformation. We conclude that confidence judgments can depend on factors other than those that improve the accuracy of memory, such as the retrieval fluency of ones memories.

Hyperbolic discounting: value and time processes of substance abusers and non-clinical individuals in intertemporal choice.

The single parameter hyperbolic model has been frequently used to describe value discounting as a function of time and to differentiate substance abusers and non-clinical participants with the models parameter k. However, k says little about the mechanisms underlying the observed differences. The present study evaluates several alternative models with the purpose of identifying whether group differences stem from differences in subjective valuation, and/or time perceptions. Using three two-parameter models, plus secondary data analyses of 14 studies with 471 indifference point curves, results demonstrated that adding a valuation, or a time perception function led to better model fits. However, the gain in fit due to the flexibility granted by a second parameter did not always lead to a better understanding of the data patterns and corresponding psychological processes. The k parameter consistently indexed group and context (magnitude) differences; it is thus a mixed measure of person and task level effects. This was similar for a parameter meant to index payoff devaluation. A time perception parameter, on the other hand, fluctuated with contexts in a non-predicted fashion and the interpretation of its values was inconsistent with prior findings that supported enlarged perceived delays for substance abusers compared to controls. Overall, the results provide mixed support for hyperbolic models of intertemporal choice in terms of the psychological meaning afforded by their parameters.