Dilution in legal decision making: Effect of non-diagnostic information in relation to amount of diagnostic evidence

Judgments about others are often based on information that varies in terms of its diagnosticity or usefulness in predicting a certain outcome. Previous studies have demonstrated a “dilution effect” in which the addition of nondiagnostic or irrelevant information yields less extreme judgments than those based solely on diagnostic information. Two studies investigated the dilution effect in a juror decision making context in which no midpoint of a scale was provided by researchers. Study 1 examined the inclusion of positive, negative, or neutral character information in a criminal case and found that this nondiagnostic information affected attitude toward the defendant but did not “dilute” guilt judgments. The cases in Study 1 contained a larger amount of diagnostic information than studies that demonstrated the dilution effect. Thus, the amount of diagnostic evidence provided was varied in Study 2, and the results showed “diluted” judgments only when a small amount of diagnostic information was presented. Limitations to the dilution effect were discussed.     

Dilution and confirmation of probability judgments based on nondiagnostic evidence

Previous research has shown that probability judgments based on a mix of diagnostic and nondiagnostic information are less extreme than judgments based on the diagnostic information alone. Results of the present experiments suggest that this dilution effect holds only under a limited set of conditions. When judgments based on a mix of diagnostic and nondiagnostic information are compared with separately elicited judgments based on the diagnostic information alone, the dilution effect is consistently observed. When judgments based on the diagnostic evidence are revised in light of additional, nondiagnostic evidence, by contrast, the dilution effect is eliminated or even reversed (yielding a confirmation effect) depending on the type of nondiagnostic evidence under evaluation.     

Separating the wheat from the chaff: does discriminating between diagnostic and nondiagnostic information eliminate the dilution effect?

The dilution effect refers to the finding that judgments are often unduly influenced by nondiagnostic information, producing regressive judgment. Because the dilution effect is a problem in various domains, strategies to control the impact of nondiagnostic information were explored by drawing on a perceptual and a conversational account of the dilution effect. Three experiments (n = 259) demonstrate that explicit instructions to discriminate between diagnostic and nondiagnostic information did not reduce the dilution effect. Rather, consistent with a perceptual explanation but not consistent with a conversational explanation, the dilution effect disappeared only when participants engage in perceptual control, that is, when they actively remove nondiagnostic pieces of information before making a judgment. Copyright © 2004 John Wiley & Sons, Ltd.     

Accountability: a social magnifier of the dilution effect

This research demonstrated that accountability can not only reduce judgmental bias, but also exacerbate it--in this case, the dilution effect. Ss made predictions from either diagnostic information alone or diagnostic information plus mixtures of additional data (nondiagnostic information, additional diagnostic data pointing to either the same conclusion or the opposite conclusion). Relative to unaccountable Ss, accountable Ss (a) diluted their predictions in response to nondiagnostic information and (b) were more responsive to additional diagnostic information. The accountability manipulation motivated subjects to use a wide range of information in making judgments, but did not make them more discriminating judges of the usefulness of that information.     

The Influence of Language Form and Conventional Wording on Judgments of Illness

Prior research indicates that category labels influence category judgments, but little is known regarding the effects for familiar categories with significant social consequences. The present studies address this issue by examining the effect of linguistic form on judgments of illnesses. Both mental and physical illnesses were presented in each of three linguistic forms: noun, adjective, and possessive phrase. In Study 1, participants were asked to judge the permanence of a set of novel illnesses that differed in wording (e.g., “He is a baxtermic”; “He is baxtermic”; “He has baxtermia”). In Studies 2 and 3, participants were asked to judge which forms of wording were most familiar for actual mental illnesses (e.g., schizophrenia) and physical illnesses (e.g., diabetes). In Study 4, participants were asked to judge the permanence of a set of familiar illnesses that differed in wording. The results indicated that for novel illnesses, nouns (“is a”) imply greatest permanence and possessive nouns (“has”) imply least permanence. However, for familiar illnesses, permanence judgments are also influenced by how frequently each form appears in ordinary language use. Mental illnesses are more often expressed with relatively permanent forms (“is” and “is a”) , whereas physical illnesses are more often expressed with relatively transient forms (“has”). The results demonstrate the importance of both linguistic form and conventional wording patterns on how categories are interpreted.     

Exploring the hardship of ease: Subjective and objective effort in the ease-of-processing paradigm

Numerous studies examined the role of processing effort in judgments using the “ease-of-processing” paradigm in which participants generate or retrieve few or many issue-relevant thoughts. Because earlier studies only assessed the subjective effort, it is unclear if this paradigm also mobilizes objective effort, and how such effort relates to subjective effort. These questions were addressed in two experiments modeled on standard tasks from the processing effort literature: “ease of argument generation” (Study 1) and “ease of retrieval” (Study 2). In both experiments we simultaneously measured subjective effort (via self-report) and objective effort (via cardiovascular reactivity). The results showed that processing ease manipulations (generation or retrieval of few vs. many exemplars) influence not only subjective effort, but also objective effort, as reflected especially by increases of systolic blood pressure in the many exemplars condition. However, only subjective effort was related to judgment. In the discussion, we consider the role of various forms of effort and other relevant variables in “processing ease” effects.     

The dilution effect: Nondiagnostic information weakens the implications of diagnostic information

In a series of studies, subjects were asked to make predictions about target individuals. Some subjects were given information about the target which pretest subjects had judged to be “diagnostic”—that is, had judged to be usefully predictive of the outcome. Other subjects were given a mix of information judged to be diagnostic and information judged to be “nondiagnostic” by pretest subjects—that is, judged to be of little value for predicting the outcome. Subjects given mixed information made much less extreme predictions than did subjects given only diagnostic information. It was argued that this “dilution effect” occurs because people make predictions by making simple similarity judgments. That is, they compare the information they have about the target with their conception of outcome categories. The presence of individuating but nondiagnostic information about the target reduces the similarity between the target and those outcomes that are suggested by the diagnostic information. One of the major implications is that stereotypes and other “social knowledge structures” may be applied primarily to abstract, undifferentiated individuals and groups and may be largely set aside when judgments are made about concrete, individuated people.     

“Remembering” emotional words is based on response bias,not recollection

Recent studies have demonstrated that emotional stimuli result in a higher proportion of recognized items that are “remembered” (e.g., Kensinger & Corkin, 2003; Ochsner, 2000), leading to greater estimates of recollection by the dual-process model (Yonelinas, 1994). This result suggests that recognition judgments to emotional stimuli depend on a recollection process. We challenge this conclusion with receiver operating characteristic (ROC) curve data from two experiments. In both experiments, subjects studied neutral and emotional words. During the recognition test, subjects made old-new confidence ratings as well as remember-know judgments. Four models of remember-know judgments were fit to individual subjects’ data: two versions of a one-dimensional signaldetection-based model (Donaldson, 1996; Wixted & Stretch, 2004), the dual-process model (Yonelinas, 1994), and the two-dimensional signal-detection-based model known as STREAK (Rotello, Macmillan, & Reeder, 2004). Consistent with the literature, we found that emotion increases subjective reports of “remembering.” However, our ROC analyses and modeling work reveal that the effect is due to response bias differences rather than sensitivity change or use of a high-threshold recollection process.     

How wearing eyeglasses affects facial recognition

Two studies examine the ability to recognize previously seen persons embedded among foils. Subjects in Study I tried to identify 20 persons among 20 foils (an easy task), whereas subjects in Study II tried to identify 50 persons among 50 foils (a difficult task). There were three independent variables: the stimulus person’s eyeglasses and sex, and the subject’s depth of processing. The first two independent variables were varied by photographs of males and females with or without glasses; depth of processing was manipulated by having subjects either judge traits (deep) or describe appearance (shallow) of the stimulus persons during the initial exposure phase. Responses were scored for “hits,” and “false alarms,” and these were transformed intod’ and β indices. Generally speaking, eyeglasses hindered facial recognition; deep processing facilitated the difficult recognition task more than the easy task; and there was a same-sex advantage in recognition. Analyses of subjects’ judgments suggest that glasses lessen attractiveness and discriminability. This project was partially supported by a grant from the Faculty Development Committee, Hanover College.     

A Smile is Just a Smile: But Only for Men. Sex Differences in Meaning of Faces Scales

This study tests psychometrics of the faces scale that is often used in organizational psychology to assess emotions, attitudes, and well-being. In analyzing 10,584 two-categorical judgments (“sad” versus “happy”) of 11 faces from 72 participants, women judged a face with a horizontal line as mouth (“neutral face”) more often sad than happy and significantly more often sad than men did. Moreover, women adapted their judgments to the range of faces under study in showing a significant contrast effect. In a range of neutral to bright smiling faces a face showing a mild smile was judged to be sad, while in a range of neutral to heavy griming faces a mild grim was judged to be happy. Sex differences in meaning of faces within faces scales and their implications for the use of the faces scale in work and organizational psychology are discussed.     

Precise instructions determine participants’ memory search strategy in judgments of relative order in short lists

Memory often requires knowledge of the order of events. Previous findings about immediate judgments of relative order in short, subspan lists are variable regarding whether participants’ strategy is to search memory in the forward direction, starting from the first list item and progressing toward the end item, or in the backward direction, starting from the end item and progressing toward the start. We asked whether wording of the instructions influences participants’ search direction. Participants studied sequences of three to six consonants, and for an immediate, two-item probe of each list, judged which probe was presented earlier (“earlier” instruction) or later (“later” instruction) on the list. Forward and backward searches were supported for “earlier” and “later” instructions, respectively. Our findings suggest that participants have more than one effective strategy for order judgments in short lists, and that subtle instructional differences can bias memory search in either the forward or backward direction.     

Which Worlds are Possible? A Judgment Aggregation Problem

Suppose the members of a group (e.g., committee, jury, expert panel) each form a judgment on which worlds in a given set are possible, subject to the constraint that at least one world is possible but not all are. The group seeks to aggregate these individual judgments into a collective judgment, subject to the same constraint. I show that no judgment aggregation rule can solve this problem in accordance with three conditions: “unanimity,” “independence” and “non-dictatorship,” Although the result is a variant of an existing theorem on “group identification” (Kasher and Rubinstein, Logique et Analyse 160:385–395, 1997), the aggregation of judgments on which worlds are possible (or permissible, desirable, etc.) appears not to have been studied yet. The result challenges us to take a stance on which of its conditions to relax.     

Is it emotion or is it stress? Gender stereotypes and the perception of subjective experience

Two studies of college undergraduates (ns = 95 and 92, primarily non-Hispanic whites and Asian Americans) investigated gender stereotypes of stress and emotion, as well as variables that influence the perception of gender-related differences. Study 1 assessed how gender stereotypes differ from the self-reports of men and women. When asked to choose a label for the subjective experience of the average man and the average woman in a series of problematic hypothetical situations, participants generally tended to believe that the average female would feel ‘emotional,” but that the average male would feel “stressed.” By contrast, the label participants chose to describe their own subjective experience was not significantly affected by their gender. In addition, participants believed the average woman and man differed more in the intensity of their emotions than in the intensity of their stress, a belief contradicted by their own self-reports. Results of Study 2 indicated that gender-related differences in estimations of stress and emotion for the self were reduced or eliminated when specific information about experience-eliciting situations was provided. We would like to thank Matthew Dank for his help in preparing the stimulus materials.     

How Japanese students reason about agricultural biotechnology

Many have claimed that education of the ethical issues raised by biotechnology is essential in universities, but there is little knowledge of its effectiveness. The focus of this paper is to investigate how university students assess the information given in class to make their own value judgments and decisions relating to issues of agricultural biotechnology, especially over genetically modified organisms (GMOs). Analysis of homework reports related with agricultural biotechnology after identification of key concepts and ideas in each student report is presented. The ideas were sorted into different categories. The ideas were compared with those in the reading materials using the same categories. These categories included: concern about affects on humans, affects on the environment, developing countries and starvation, trust in industry, responsibility of scientists, risk perception, media influence, need for (international) organizations or third parties, and information dissemination. What was consistent through the different years was that more than half of the students took a “neutral” position. A report was scored as “neutral” when the report included both the positive and negative side of an issue, or when the student could not make a definite decision about the use of GMOs and GM food. While it may be more difficult to defend a strong “for” or “against” position, some students used logical arguments successfully in doing so. Sample comments are presented to depict how Japanese students see agricultural technology, and how they value its application, with comparisons to the general social attitudes towards biotechnology.     

Teachers facing school failure: the social valorization of effort in the school context

This paper describes two studies concerning teachers’ classroom interventions facing school failure. The role of two main variables is investigated: the lack of effort as a cause of failure students are held responsible for by teachers, and teacher’s social representations of intelligence. The first study (Study 1) explored the impact of “lack of effort” causal attribution for student’s failure on the intervention strategies adopted by 122 high school teachers. Study 2 analyzed the impact of social representations of intelligence, held by 202 high school teachers, on “lack of effort” causal inference and on behavioral interventions. Results highlight that teachers mostly choose more severe educational interventions with retributive purpose when failure is ascribable to an absence of effort expenditure by the student. Moreover, the findings support the role of teachers’ social representations of intelligence in failure explanations and in educational practices, showing that “lack of effort” attribution and practices with retributive purpose are predicted by the social representation of intelligence “as a gift”. Results are analyzed and discussed by considering the effort as a normative parameter of the school environment. This research was supported financially in part by MURST “University funds, 2004 (Ex 40%)”. Portions of these results were presented at the 8th International Conference on Social Representations, Rome.     

The revelation effect for autobiographical memory: A mixture-model analysis

Participants provided information about their childhood by rating their confidence about whether they had experienced various events (e.g., “broke a window playing ball”). On some trials, participants unscrambled a key word from the event phrase (e.g., wdinwo—window) or an unrelated word (e.g., gnutge—nugget) before seeing the event and giving their confidence ratings. The act of unscrambling led participants to increase their confidence that the event occurred in their childhood, but only when the confidence rating immediately followed the act of unscrambling. This increase in confidence mirrors the “revelation effect” observed in word recognition experiments. In the present article, we analyzed our data using a new signal detection mixture distribution model that does not require the researcher to know the veracity of memory judgments a priori. Our analysis reveals that unscrambling a key word or an unrelated word affects response bias and discriminability in autobiographical memory tests in ways that are very similar to those that have been previously found for word recognition tasks.     

What Determines Perceived Quality-of-life Impact of Mobile Phones? A Model Based on the Consumption Life Cycle

This paper reports two studies designed to identify the determinants of perceived quality-of-life impact (PQOLI) of mobile phones. We hypothesized that PQOLI of mobile phones is determined by mostly global feelings of satisfaction with mobile phones, which in turn are determined by satisfaction with a broad range of customer-related experiences—experience with the purchase of the mobile phone and service, preparing the mobile phone for personal use, using the mobile phone, owning the mobile phone, maintenance and repairs of the mobile phone, and disposal of the mobile phone (stages in the consumption life cycle). “Study 1” focused testing the model using a college student population. “Study 2” was designed to replicate the findings of “Study 1” with a more mature and diverse consumer population and extend the model by demonstrating that PQOLI has a significant predictive influence on brand loyalty, thus underscoring the managerial utility of our model. The study results are supportive of our overall model and its hypotheses.     

Should goal-strivers think about “why” or “how” to strive? It depends on their skill level

The current studies attempted to increase individuals’ internalization of their own difficult or unpleasant goals, using either a low-level or a high-level writing intervention. Two writing studies showed that an appropriate match between level of goal-relevant skill (low versus high) and level of prompted goal-cognition (low versus high) enhances motivation. Those lower in initial skills were more likely to internalize their goals over time (Studies 1 and 2) and report greater goal expectancies (Study 2) if they wrote about the “how” of the goals, whereas those higher in initial skills were more likely to experience these positive outcomes by writing about the “why” of goals. This interaction pattern was found in both a short-term experimental study of health goals (Study 1) and in a 2 month longitudinal study of academic goals (Study 2). Results are discussed in the context of action identification theory and of self-regulation, which emphasize allocating attention to the right level of abstraction for optimal functioning.     

Too much information: the perils of nondiagnostic information in negotiations

Two studies showed that possessing information about a negotiation counterpart that is irrelevant to the negotiation task can impair negotiators' effectiveness because such knowledge impedes effective information exchange. In Study 1, negotiators who possessed diagnostic and nondiagnostic forms of information were each less likely to exchange information about their preferences within the negotiation. However, only those negotiators who possessed nondiagnostic information achieved inferior negotiation outcomes as a result. In Study 2, negotiators possessing nondiagnostic information about their counterparts in electronically mediated negotiations were more likely to terminate the search for mutually beneficial outcomes prematurely and declare impasses. They were also less able to use diagnostic forms of information to make mutually beneficial trade-offs. As a result, negotiators in these dyads achieved inferior outcomes.     

What “Intuitions” are Linguistic Evidence?

In “Intuitions in Linguistics” (2006a) and Ignorance of Language (2006b) I took it to be Chomskian orthodoxy that a speaker’s metalinguistic intuitions are provided by her linguistic competence. I argued against this view in favor of the alternative that the intuitions are empirical theory-laden central-processor responses to linguistic phenomena. The concern about these linguistic intuitions arises from their apparent role as evidence for a grammar. Mark Textor, “Devitt on the Epistemic Authority of Linguistic Intuitions” (2009), argues that I have picked the wrong intuitions: I should have picked non-judgmental linguistic “seemings”. These reside between metalinguistic judgments and linguistic performances and have an epistemic authority that the orthodox view may well be able to explain. Textor seems to think that the metalinguistic intuitions are not evidence at all. I argue that he is wrong about that. More importantly, I argue that there are no “in-between” linguistic seemings with epistemic authority.