Reid Hastie

Evidence evaluation in complex decision making.

This study investigates the role of representation of evidence in a jurors decision process. A model is presented that includes an initial stage of processing in which cognitive representations of the evidence in the form of stories are produced. This is followed by a computation of the decision by evaluating the goodness-of-fit of the evidence representation (story) to the verdict categories. Subjects, drawn from jury pools, made individual decisions on the verdicts for a filmed murder trial. Extensive interviews provided the data for analysis of their cognitive representations of the evidence in the case, the verdict categories presented in the trial judges instructions, and the procedures they were to follow according to law to reach a verdict. We found, as hypothesized, that the trial evidence was represented in a story form. Furthermore, differences among jurors in cognitive representations of evidence were correlated with their verdicts, although other aspects of the decision process (verdict category representations, application of the standard of proof procedural instruction) were not. We conclude that adequate theories of decision making must emphasize cognitive aspects of performance, such as the representation of evidence.

Social perception in negotiation

Abstract Many negotiations provide opportunities for integrative agreements in which parties can maximize joint gains without competing for resources in a direct win-lose fashion. However, negotiators often settle for suboptimal compromise agreements rather than search for mutually beneficial, or integrative, agreements. We hypothesized that misperceptions of the other partys interests are a primary cause of suboptimal outcomes. Two studies examined the role of social perception in negotiation and the relationship between judgment accuracy and negotiation performance. Results indicated that: most negotiators enter negotiation expecting the other partys interests to be completely opposed to their own; negotiators learn about the potential for joint gain during negotiation; most learning occurs within the first few minutes of interaction; accurate perception of the other partys interests leads to better negotiation performance; negotiators who learn about the other partys interests in the early stages of negotiation earn higher payoffs than do those who learn during the later stages of negotiation; a substantial number of negotiators fail to realize when they have interests that are completely compatible with those of the other party and settle for suboptimal agreements; and the two types of judgment error, Fixed Sum Error and Incompatibility Error, appear to be unrelated, distinct judgment errors. We discuss the role of social judgment in negotiation and the generalizability of the results to real world negotiations.

Explaining the evidence: Tests of the Story Model for juror decision making.

This research investigates the Story Model, Pennington and Hasties (1986, 1988) explanationbased theory of decision making for juror decisions. In Experiment 1, varying the ease with which stories could be constructed affected verdict judgments and the impact of credibility evidence. Memory for evidence in all conditions was equivalent, implying that the story structure was a mediator of decisions and of the impact of credibility evidence. In Experiments 2 and 3, Ss evaluated the evidence in 3 ways. When Ss made a global judgment at the end of the case, their judgment processes followed the prescriptions of the Story Model, not of Bayesian or linear updating models. When Ss made item-by-item judgments after each evidence block, linear anchor and adjust models described their judgments. In conditions in which story construction strategies were more likely to be used, story completeness had greater effects on decisions.

The Robust Beauty of Majority Rules in Group Decisions

How should groups make decisions? The authors provide an original evaluation of 9 group decision rules based on their adaptive success in a simulated test bed environment. When the adaptive success standard is applied, the majority and plurality rules fare quite well, performing at levels comparable to much more resource-demanding rules such as an individual judgment averaging rule. The plurality rule matches the computationally demanding Condorcet majority winner that is standard in evaluations of preferential choice. The authors also test the results from their theoretical analysis in a behavioral study of nominal human group decisions, and the essential findings are confirmed empirically. The conclusions of the present analysis support the popularity of majority and plurality rules in truth-seeking group decisions.

An Information-Processing Analysis of Graph Perception

Abstract Recent work on graph perception has focused on the nature of the processes that operate when people decode the information represented in graphs. We began our investigations by gathering evidence that people have generic expectations about what types of information will be the major messages in various types of graphs. These graph schemata suggested how graph type and judgment type would interact to determine the speed and accuracy of quantitative information extraction. These predictions were confirmed by the finding that a comparison judgment was most accurate when the judgment required assessing position along a common scale (simple bar chart), had intermediate accuracy on length judgments (divided bar chart), and was least accurate when assessing angles (pie chart). In contrast, when the judgment was an estimate of the proportion of the whole, angle assessments (pie chart) were as accurate as position (simple bar chart) and more accurate than length (divided bar chart). Proposals for elementa...

Reasoning in explanation-based decision making

A general theory of explanation-based decision making is outlined and the multiple roles of inference processes in the theory are indicated. A typology of formal and informal inference forms, originally proposed by Collins (1978a, 1978b), is introduced as an appropriate framework to represent inferences that occur in the overarching explanation-based process. Results from the analysis of verbal reports of decision processes are presented to demonstrate the centrality and systematic character of reasoning in a representative legal decision-making task.

Inside the juror: The story model for juror decision making

Introduction The goal of our research over the past ten years has been to understand the cognitive strategies that individual jurors use to process trial information in order to make a decision prior to deliberation. We have approached this goal with the perspective of psychologists who are interested in how people think and behave. First, we have developed a theory that we believe describes the cognitive strategies that jurors use. We call this theory the story model, and it is described in the first section of the paper. Second, we have conducted extensive empirical work to test the theory. This work is summarized in the second section of the paper. The story model has been developed in the context of criminal trials, so it will be presented and discussed in those terms. In the final section of the paper, we discuss some of our current research directions. The story model We call our theory the story model because we propose that a central cognitive process in juror decision making is story construction (Bennett & Feldman, 1981; Pennington, 1981, 1991; Pennington & Hastie, 1980, 1981a, 1981b, 1986, 1988, 1992). Although story construction is central in our theory and has been the focus of most of our empirical research, it is but one of three processes that we propose.

Causal knowledge and categories: The effects of causal beliefs on categorization, induction, and similarity

Despite the recent interest in the theoretical knowledge embedded in human representations of categories, little research has systematically manipulated the structure of such knowledge. Across four experiments this study assessed the effects of interattribute causal laws on a number of category-based judgments. The authors found that (a) any attribute occupying a central position in a network of causal relationships comes to dominate category membership, (b) combinations of attribute values are important to category membership to the extent they jointly confirm or violate the causal laws, and (c) the presence of causal knowledge affects the induction of new properties to the category. These effects were a result of the causal laws, rather than the empirical correlations produced by those laws. Implications for the doctrine of psychological essentialism, similarity-based models of categorization, and the representation of causal knowledge are discussed.

Decision and experience : why don't we choose what makes us happy?

Recent years have witnessed a growing interest among psychologists and other social scientists in subjective well-being and happiness. Here we review selected contributions to this development from the literature on behavioral-decision theory. In particular, we examine many, somewhat surprising, findings that show people systematically fail to predict or choose what maximizes their happiness, and we look at reasons why they fail to do so. These findings challenge a fundamental assumption that underlies popular support for consumer sovereignty and other forms of autonomy in decision-making (e.g. marriage choice), namely, the assumption that people are able to make choices in their own best interests.

What’s Next? Judging Sequences of Binary Events

The authors review research on judgments of random and nonrandom sequences involving binary events with a focus on studies documenting gamblers fallacy and hot hand beliefs. The domains of judgment include random devices, births, lotteries, sports performances, stock prices, and others. After discussing existing theories of sequence judgments, the authors conclude that in many everyday settings people have naive complex models of the mechanisms they believe generate observed events, and they rely on these models for explanations, predictions, and other inferences about event sequences. The authors next introduce an explanation-based, mental models framework for describing peoples beliefs about binary sequences, based on 4 perceived characteristics of the sequence generator: randomness, intentionality, control, and goal complexity. Furthermore, they propose a Markov process framework as a useful theoretical notation for the description of mental models and for the analysis of actual event sequences.