Article

The dilution effect: The role of the correlation and the dispersion of predictor variables in the use of nondiagnostic information

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Abstract

Proposed that people make predictions by making judgments of similarity between the target and an outcome based on shared features. In 1 preliminary and 2 main studies, 149 undergraduates made predictions about GPAs of target students. Controls received only information predictive of a high or low GPA. Experimental Ss received information predictive of a high or low GPA and additional information describing the other target as average on several other dimensions. In some descriptions, the dimensions were strongly or poorly correlated with GPA. In other descriptions, dimensions were all poorly correlated with GPA and were broadly or narrowly dispersed. Ss receiving the mixed information regressed their GPA predictions back to the mean GPA and did so to the same extent whether the information was believed to be drawn from well or poorly correlated dimensions. Nondiagnostic information drawn from broadly dispersed dimensions produced substantially more regressive predictions than nondiagnostic information drawn from narrowly dispersed dimensions. (22 ref) (PsycINFO Database Record (c) 2012 APA, all rights reserved)

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... The dilution effect has been found in many different tasks, including tasks with objective probabilities that ask participants to reason about the likelihood that a set of poker chips were drawn from one of two book bags (Labella & Koehler, 2004;Shanteau, 1975;Troutman & Shanteau, 1977), tasks that ask for predictions about the behavior of people (Nisbett, Zukier, & Lemley, 1981;Zukier, 1982), tasks asking for consumers' judgments of products (Meyvis & Janiszewski, 2002), and even perceptual tasks (Hotaling, Cohen, Shiffrin, & Busemeyer, 2015;Yurovsky, Boyer, Smith, & Yu, 2013). High-stakes judgments are not immune to the dilution effect. ...
... For the dilution effect juror example above, the diagnostic information that the man was known to argue with his aunt and had no alibi increases the similarity of the man to the judgment of guilt, while the non-diagnostic information that the man is of average height and has average vision are distinctive from the features commonly associated with a murderer, and thus reduce the similarity between the man and the judgment of guilt. Therefore, representativeness predicts a dilution effect (Kahneman & Tversky, 1972;Nisbett et al., 1981;Zukier, 1982). ...
... Most previous research on the dilution effect has used subjective rather than objective evidence, which means whilst the difference between D and D+ND evidence can be assessed, the overall levels of each cannot. Examples have included using personality characteristics as evidence when predicting a student's future grade point average (Zukier, 1982), or using a face morph as evidence when judging which of the two real faces the morph resembles more (Hotaling et al., 2015). ...
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Article
When asked to combine two pieces of evidence, one diagnostic and one non-diagnostic, people show a dilution effect: the addition of non-diagnostic evidence dilutes the overall strength of the evidence. This non-normative effect has been found in a variety of tasks and has been taken as evidence that people inappropriately combine information. In a series of five experiments, we found the dilution effect, but surprisingly it was not due to the inaccurate combination of diagnostic and non-diagnostic information. Because we have objectively correct answers for our task, we could see that participants were relatively accurate in judging diagnostic evidence combined with non-diagnostic evidence, but overestimated the strength of diagnostic evidence alone. This meant that the dilution effect - the gap between diagnostic evidence alone and diagnostic evidence combined with non-diagnostic evidence - was not caused by dilution. We hypothesized that participants were filling in "missing" evidence in a biased fashion when presented with diagnostic evidence alone. This hypothesis best explained the experimental results.
... For instance, LaBella andKoehler (2004, p. 1076) refer to the dilution effect, if ''judgments based on a combination of diagnostic and nondiagnostic evidence tend to be less extreme than judgments based on the diagnostic evidence alone.'' The same or extremely similar definitions are provided by Nisbett et al. (1981, p. 251), Zukier (1982, p. 1164, Zukier andJennings (1983/84, p. 187), Tetlock andBoettger (1989, p. 389), Simonson et al. (1994, p. 26), Shelton (1999, p. 217), Peters and Rothbart (2000, p. 177), Meyvis and Janiszewski (2002, p. 619), Kemmelmeier (2004, p. 231), and Igou and Bless (2005, p. 26). Based on the distinction of information according to diagnosticity and valence, we can illustrate the dilution effect formally. ...
... Diagnostic attributes are features that are possessed by both the stimulus object and the category it belongs to (Nisbett et al. 1981, p. 250). Nondiagnostic attributes are perceived as non-typical attributes and are defined as having ''no predictive value and are therefore not contained in the conception of the outcome'' (Zukier andJennings 1983/1984, p. 189). Thus, they are treated as distinctive features. ...
... If people pay attention to non-diagnostic information, the evaluation of a stimulus object will be less extreme because non-diagnostic attributes reduce the similarity between an extreme category and the stimulus object (Nisbett et al. 1981, p. 251). For example, if people are asked to estimate the grade point average of a student, non-diagnostic information (e.g., the information that a student plays tennis) reduces the similarity with a very good or with a very bad student respectively, resulting in a more moderate forecast of this student's grade point average (Zukier 1982(Zukier , p. 1164Tetlock and Boettger 1989, p. 389). ...
Article
This study examines the interaction effect of the dilution effect and the connotation transfer effect on product evaluation. We start our investigation with the finding that advertisements often contain verbal non-diagnostic information. For instance, using embellished labels or fancy names, referring to completely unknown or unneeded attributes, and providing information on sponsorships usually does not transmit information on product benefits the consumer is interested in. Thus, the consumer can not rely on this information to evaluate the product. This is a typical case where a dilution effect is expected to occur. However, this kind of information additionally could evoke positive connotations that are transferred to the advertised product. Until now, there is no systematic research on the interplay of both effects. In three experiments, we manipulate diagnostic information and the valence of verbal non-diagnostic information and analyze which effect overweighs. We found that a positive connotation transfer effect (i.e., spill-over effect) proved to dominate the negative dilution effect in the positive diagnostic information condition.
... Decades of research has demonstrated the negative impact that providing nondiagnostic information to decision makers can have on decision-making performance (e.g., Carr et al., 2017;Nisbett et al., 1981;Waller & Zimbelman, 2003;Zukier, 1982). This is particularly relevant for selection decision makers 1 who have access to information from myriad sources (e.g., LinkedIn, Facebook, references) from which they can acquire job relevant (e.g., skills and abilities) as well as job irrelevant (e.g., fandom for a specific sport team) information about a candidate (Highhouse, 1997). ...
... The detrimental impact of nondiagnostic information on social judgments (i.e., predictions of others) was demonstrated in a series of studies by Nisbett and colleagues (1981) and Zukier (1982; though see Troutman & Shanteau [1977] for a demonstration in nonsocial judgment). In these studies, participants who received only diagnostic information made more accurate predictions of others than participants who received, in addition to the same diagnostic information, some nondiagnostic information. ...
... The confounding effects of typicality may be present in other research on the dilution effect as well. Zukier (1982), for example, examined the impact of adding nondiagnostic items perceived as either varying widely in his college student population (e.g., some students date a lot, whereas others do not date at all) or as being narrowly dispersed (e.g., all students have about the same number of close friends). Nondiagnostic items drawn from broadly dispersed dimensions (e.g., the number of dating partners in a given year) caused more dilution of a grade point average (GPA) prediction than did nondiagnostic items drawn from narrowly dispersed dimensions. ...
... Using Zukier's example, a student who scored high on the Scholastic Aptitude Test (SAT) who dated three people during the school year may be a less typical high-SAT student and, thus, may receive a lower GPA prediction. A similar analysis can be made of Zukier andJennings's (1983-1984) article. Fein and Hilton (1992) also argued that not all nondiagnostic information is equally diluting and distinguished between nondiagnostic information that was perceived as being broadly useful for most social judgments (pseudorelevant or high in typical diagnosticity) or not useful for most social judgments (irrelevant or low in typical diagnosticity). ...
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Article
Nisbett, Zukier and Lemley presented evidence for a "dilution effect," in which information nonpredictive of a stimulus person's behavior "watered down" or diluted the predictive value of categorical information diagnostic of that behavior Two experiments suggest, however that nondiagnostic information influences prediction by altering the perceived goodness of fit between the stimulus person and the diagnostic category. The authors conclude that (a) Nisbett et al. found evidence for dilution because their nondiagnostic items decreased the goodness of fit between the stimulus person and the diagnostic category and (b) depending on the typicality of the nondiagnostic items, it is possible to dilute, enhance, or leave unchanged the predictability between category and behavior The structure of social categories, and the importance of typicality in the stereotyping process, is discussed.
... There have been a number of errors or biases associated with the representativeness heuristic, three of whichÐbase-rate error (Kahneman & Tversky, 1973), the conjunction fallacy (Tversky & Kahneman, 1983), and the dilution eect (Zukier, 1982)Ð have been subject to alternative, conversational explanations. We will consider each of these in turn. ...
... A similar process of informational reinterpretation likely accounts for the`dilution' eect, wherein highly diagnostic information is diluted by the addition of nondiagnostic information (Tetlock et al., 1996). Assuming the relevance of the nondiagnostic information plausibly caused participants to overestimate its actual diagnosticity, though not because, as Zukier (1982) suggests, people tend to 5 In fact, we suspect no more or less dicult than the notorious`frame-problem' that has vexed philosophers and A.I. researchers for years. Imagine, for example, trying to program a robot to`consider' all and only those factors relevant to the goal of opening a can of beans (see Dennett, 1984). ...
Article
An impressive body of evidence has accumulated demonstrating that many of the judgmental ‘errors’ or ‘biases’ formerly thought due to purely cognitive shortcomings actually reflect the operation of communication goals and strategies that people rely upon to comprehend and generate meaningful conversation. This study examines the effects of individual differences in conversational skills on the production of biased responses using six judgmental heuristics tasks: base-rate error, conjunction error, dilution effect, underuse of consensus information, primacy effect, and confirmation bias. Clarke's (1975) ‘method of reconstruction’ was used to obtain two measures of conversational sophistication: relevance-seeking and (un)responsiveness. A path analysis predicting biased judgments from the skill variables demonstrates that a combination of these variables, which we term ‘Pragmatic Competence’, is predictive of two independent subsets of the heuristics tasks. Our model provides convergent evidence with other, parametric studies for the proposition that biased social judgments are, at least in part, artifacts of participants' reasonable (and unreasonable!) expectations concerning experimenter cooperativeness. ‘The process of forming an integrated mental model of premises is nothing more than the proper comprehension of discourse: it is required in order to grasp the full impact of what the speaker has to say’ Johnson-Laird (1983, p. 119).
... Dispositional inferences are attenuated when participants are told that their information packages were randomly selected from a larger pool and may not always include information pertinent to the specific questions asked (Wright & Wells, 1988). Other research showed that adding nondiagnostic information dilutes the impact of diagnostic information, indicating that people consider both types of information and fail to appropriately weight the inputs by their diagnosticity (Nisbett, Zukier, & Lemley, 1981;Zukier, 1982). Again, this dilution effect is attenuated or eliminated when the conversational guarantee of relevance is called into question (Igou & Bless, 2005;Tetlock, Lerner, & Boettger, 1996). ...
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Chapter
People do much of their thinking in a social context by drawing on information provided by others and sharing their own judgments with others. This exchange is guided by the tacit assumptions underlying the conduct of conversations in everyday life. This chapter reviews these assumptions and their implications for social cognition research. It highlights that many familiar biases and shortcomings of human judgment reflect, in part, a basic misunderstanding about the nature of communication in research situations. Whereas participants assume that researchers are cooperative communicators, whose contributions are informative, relevant, and clear, the researchers may (deliberately or inadvertently) present information that does not meet these criteria. When this misconception is avoided, many familiar biases are attenuated or eliminated, suggesting that they are the result of faulty communication rather than faulty judgment.
... Research indicates that "parents, especially mothers, socialize their children to perceive separate roles for men and women within society," suggesting that mothers play a more significant role in gender stereotyping their daughters [5]. Several studies prove that despite massive exposure to children's individual information, mothers are still influenced by gender stereotypes and, thus, they can't gain an objective perception of their children's ability or potential [9][10][11][12]. ...
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Conference Paper
This paper investigates whether social, family and economic factors affect gender stereotyping on females under different educational systems. This investigation benefits eliminating gender stereotyping in Chinese society, facilitating gender equality and economic growth in future China. In the research, a sample of 17 female students from different educational backgrounds was interviewed online by dividing into focus groups based on their educational experience. The results show that Chinese female students are all influenced by Chinese traditional or social values, and the extent of the impact depends on the contact level. School and family environments play an essential role in forming and influencing students’ thoughts on gender expectations, consequently influencing students’ major-choice in college and future career planning. Also, the results support our hypothesis that Chinese female students in American high school who are exposed to fewer gender stereotypes or discriminations would show more self-confidence, which will impact their career and major selection in university. This research enables society and families to be aware of its influence on gender stereotyping on female students, and schools can modify its pedagogy to reduce gender stereotypes in education. Consequently, gender stereotypes and discrimination can have less impact on females, and they can participate in more economic and social activities regardless of their gender concerns.
... More information increases confidence of people who are expert in certain domain of knowledge (Oskamp, 1965) but at the same time reduces the weight of statistical cues on prediction (Nisbett et al., 1981;Zukier, 1982) and decreases overall prediction accuracy (Hall et al., 2007) Amount of information Confidence Belief Accuracy Table 1. Existing theories of information in online communities SAJBS 10,3 ...
Article
Purpose The focus of this study lies in understanding the extrinsic vs intrinsic motivators which drive the m-coupon sharing behaviour in social networking sites (SNSs). A consumer can make promotional tool (in our case m-coupons) viral if the cues trigger an apt motivation. This study fills the need gap by identifying which motivations must be focused to make a promotional tool viral by the consumer especially in an emerging economy like India. Design/methodology/approach We designed conceptual framework based on extensive literature review and employed hierarchal regression methodology to investigate the motivation to share m-coupon. Findings Sense of self-worth, Socializing and Reciprocity emerge as strong reasons for a consumer to share m-coupons amongst friends and peers in SNS. Results have shown that intrinsic motivation works very effectively when a consumer shares m-coupons in SNSs. Research limitations/implications This study has certain limitations. First, the impact of age, gender and education can also influence the results as perception evolves with age and education. Second, in our study, we have not classified m-coupons in different categories. Different types of m-coupons may have a different impact on consumers. Practical implications The paper presents findings, which are useful for marketers to develop a customer-centric viral promotional strategy. Originality/value This study is one of the few studies in integrating types of motivation with coupon proneness and coupon sharing in social media. This study has specifically targeted the emerging economy where m-coupons usage has seen a surge. Study has shown that it is the intrinsic motivation which is very crucial for encouraging consumer for participating in SNSs and share e-word of mouth amongst friends and peers.
... The dilution effect refers to the reduction in the weight given to diagnostic information when that information is diluted with nondiagnostic information. The inclusion of nondiagnostic information obviously should not have an effect on judgments -yet it frequently does (e.g., Nisbett, Zukier, and Lemley 1981;Zukier 1982). For example, participants generated strong inferences about a student's GPA when told he studied 3 hours versus 31 hours per week. ...
... This is because preferences and beliefs are constructed on the spot unless a pre-existing preference or belief is accessible in memory and sufficiently diagnostic for the question at hand, in which case the pre-existing cognition will be used instead. In fact, past research has identified several cases and conditions in which answers to prior questions are used to approximate answers to subsequent questions (Lynch, Marmorstein, and Weigold 1988;Menon & Raghubir, 2003; Menon, For example, research on the dilution effect shows that giving people information that provides little or no additional predictive power generally makes their predictions worse (Edgell et al., 1996;Nisbett, Zukier, & Lemley, 1981;Troutman & Shanteau, 1977;Zukier, 1982). For example, Nisbett and colleagues (1981) had graduate students in social work rate the likelihood that a hypothetical client was a child abuser based on information that was judged by other social work students to be diagnostic (e.g., "he was abused by his stepfather") and information that was judged to be nondiagnostic (e.g., "he manages a hardware store"). ...
Article
In this paper, we investigate whether making detailed predictions about an event makes other predictions worse. Across 19 experiments, 10,895 participants, and 415,960 predictions about 724 professional sports games, we find that people who made detailed predictions about sporting events (e.g., how many hits each baseball team would get) made worse predictions about more general outcomes (e.g., which team would win). We rule out that this effect is caused by inattention or fatigue, thinking too hard, or a differential reliance on holistic information about the teams. Instead, we find that thinking about game-relevant details before predicting winning teams causes people to give less weight to predictive information, presumably because predicting details makes information that is relatively useless for predicting the winning team more readily accessible in memory and therefore incorporated into forecasts. Furthermore, we show that this differential use of information can be used to predict what kinds of games will and will not be susceptible to the negative effect of making detailed predictions.
... 31 Furthermore, with so much online news information, irrelevant information can dilute the impact of relevant information in social capital development. 32 People also can use the Internet to create insular zones in which they consume information that is highly consistent with their preexisting attitudes and beliefs. 33 Finally, whereas online print news stories share commonalities in user control, organization, and structure with traditional print newspapers, 34 audio and video online news provides breaks from such presentation patterns and permits less user control. ...
Article
The current study builds and empirically tests a theoretical model in which news use influences health outcomes directly and indirectly, as mediated by neighborliness with specific ethnic groups. With telephone survey data from 2007, a well-fitting structural equation model indicates direct and indirect effects of news use measures on two health outcomes: health status and stress. Effects of newspaper news use were more favorable than those via television and online news, and effects of neighborliness with whites and with Asians were more favorable on health outcomes than effects of neighborliness with blacks and with Hispanics.
... Often their judgements are based on what has been provided whilst ignoring what has been excluded (Islam, Louviere, & Burke, 2007;Kardes, Posavac, & Cronley, 2004). Indeed, this can lead to a 'provision bias', even to the extent that non-diagnostic or irrelevant information can influence product choices (Meyvis & Janiszewski, 2002;Zukier, 1982). Such findings highlight the importance of the search for and use of WOM on the part of receivers, and the inadequacy of that search behaviour. ...
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Article
Word-of-Mouth communication is an invaluable source of information for consumers. A comprehensive understanding of the flow of market information through interpersonal networks is therefore of unique theoretical and practical importance. Present Word-of-Mouth research is receiver centric, largely ignoring the role of the information provider as a gatekeeper to information dissemination. The objective of this research is to develop a more comprehensive understanding of Word-of-Mouth by modelling the decision making behaviour of information providers. Adopting the network theory general assumption of altruistic exchange motivation, this research uses a choice modelling framework to demonstrate that information providers assign greater utility to (1) information about product features important to the receiver, and (2) information which disconfirms receiver preferences. In addition, these effects are found to be moderated by perceptions about the receivers knowledge. Existing research has not previously considered information providers perceptions of receivers as a potential moderator of WOM flow, with the results here suggesting this should be an area of future investigation.
... Los trabajos sobre el heurístico de representatividad generalmente se ciñen a una pequeña cantidad de información, de tal forma que nos conduce casi necesariamente a preguntarnos qué ocurre cuando el individuo maneja una cantidad mayor de información, como acontece en muchas de las situaciones cotidianas. Las aportaciones al respecto han detectado el denominado efecto del diluido, que pone de manifiesto que los pronósticos de las personas se hacen menos extremos, cuando cuentan con una cierta cantidad de información, atenuándose el sesgo de representatividad (Nisbett y Ross, 1980;Nisbett et al., 1981;Zukier, 1982). ...
... Normatively, only information possessing predictive value with respect to a hypothesis should be incorporated into the decision-making process. Yet, psychology studies report that the introduction of non-diagnostic or irrelevant information often results in judgments that systematically differ from those based solely on predictive information (Nisbett et al. 1981;Zukier 1982;Edgell et al. 1996). ...
Article
This study provides evidence that in a fraud risk assessment task, decision aid use increases auditor susceptibility to dilution, an information processing bias where non-predictive cues "water down" or dilute the predictive value of diagnostic cues. The results of a between-subjects experiment, in which senior auditors assessed fraud risk, indicate that in response to irrelevant information, decision-aided auditors lowered their fraud assessments more than did their unaided counterparts. Even in a high fraud risk context, where auditors should be particularly thoughtful as they review data in preparation for assessing fraud risk, the decision aid still impaired judgment.
... Note that this extreme group method maximizes statistical power; however, because the individual difference variable no longer presents a continuous distribution, regression approaches as advocated by West et al. (1996) cannot be employed. On a task previously used by several researchers (e.g., Kemmelmeier, 2004; Nisbett et al., 1981; Tetlock & Boettger, 1989; Zukier, 1982), participants were asked to predict the likelihood that the target person was a child abuser using an 11- point scale with 1 = not at all likely and 11 = very likely. Instructions specified that participants should circle 6, the midpoint of the likelihood scale, if they felt unsure (conversational norm applicable) or if they felt they did not have any useful information to make a judgment (conversational norm inapplicable). ...
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Article
The dilution effect refers to the finding that judgments are often unduly influenced by nondiagnostic information, producing regressive judgment. The hypothesis of a conversational basis of the dilution effect, advanced in a recent study by Igou and Bless, holds that the effect reflects the operation of the conversational norm of relevance. A critique and reanalysis of their data yields only weak, if any, support for this conversational explanation. Furthermore, an experiment (n = 224) does not yield any supportive evidence, and a meta-analysis of available studies likewise supports the conclusion that the dilution effect occurs independently of the operation of conversational norms. However, consistent with a social-perceptual explanation, the experiment shows that the dilution effect occurs only for individuals high in personal need for structure. Although conversational norms do not provide the basis for the dilution effect, how they are involved in eliminating this reasoning error is discussed.
... If children average, as found in the simple context of the present study, this may provide clues to adult performance in similar, but more complex contexts: Averaging is one of several possible explanations for the subadditivity previously reported in adults' expected value judgement (see review inShanteau, 1975a). Averaging may also account for characteristic deviations from the Bayesian model of opinion revision (Birnbaum & Mellers, 1983;Nisbett & Ross, 1980;Nevemsky & Kronzon, 1999;Shanteau, 1975b;Zukier, 1982). This is in line with current approaches to cognition that emphasise the continuity of child and adult thought (e.g.,Karmiloff-Smith, 1992).Wright, 1984, Baron, 1994). ...
Article
Violations of utility are often attributed to people's differential reactions to risk versus certainty or uncertainty, or more generally to the way that people perceive outcomes and consequences. However, a core feature of utility is additivity, and violations may also occur because of averaging effects. Averaging is pervasive in intuitive riskless judgement throughout many domains, as shown with Anderson's Information Integration approach. The present study extends these findings to judgement under risk. Five- to 10-year old children showed a disordinal violation of utility because they averaged the part worths of duplex gambles rather than add them, as adults do, and as normatively prescribed. Thus adults realized that two prizes are better than one, but children preferred a high chance to win one prize to the same gamble plus an additional small chance to win a second prize. This result suggests that an additive operator may not be a natural component of the intuitive psychological concept of expected value that emerges in childhood. The implications of a developmental perspective for the study of judgement and decision are discussed. Copyright © 2000 John Wiley & Sons, Ltd.
... For example, a lottery outcome of 1, 2, 3, 4, 5, and 6 is seen as less representative of lottery outcomes than 12, 27, 29, 32, 34, and 41 (Strack, 1993); therefore, according to the representativeness heuristic are more optimistic about the second than on the first outcome. Nisbett, Zukier, and Lemley (1981) and Zukier (1982) examined what happens if people make prediction of an outcome when besides diagnostic information nondiagnostic information is also presented. For example, when people predict the GPA of a student, diagnostic information could be the amount of time that the student is studying, non-diagnostic information could be the love that the student feels for her grandma. ...
... That subjects may rely heavily on information provided by the experimenter simply because it is provided, although it may seem irrelevant on substantive grounds, is not unknown to social psychologists. Zukier (1982) provided subjects with infor-mation about a target's studying time and asked them to predict the target's grade point average. He found that adding worthless information (e.g. ...
Article
Conversational rules of everyday communication are applied to the interaction between experimenters and subjects. According to these rules, contributions to a communication should be informative, relevant, true, and unambiguous. It is assumed that subjects determine the pragmatic meaning of instructions and questions on the basis of these rules and the provided context. In contrast to most natural settings, standardized experimental procedures rarely allow for an interactive determination of pragmatic meaning and often preclude feedback as a corrective device. As a consequence, subjects are required to rely heavily on general rules, and even subtle cues may become informationally loaded. The information extracted from context cues may often not be intended by the experimenter. Thus subjects may infer more than they are supposed to, resulting in discrepancies between the experimenter's intended and subjects' inferred meaning of the instructions. If researchers are not sensitive to the information provided by verbal and non-verbal context cues, their interpretation of research results may be based on biased data. Evidence from different research domains is reported to support the presented assumptions and their implications for bias avoiding strategies are discussed.
Article
A preregistered replication was conducted to examine the evidence for the basic dilution effect in a performance prediction context. Participants (n = 796) were presented with either diagnostic information alone or diagnostic + nondiagnostic information in a grade point average (GPA) prediction task. The diagnostic information was either indicative of a low GPA or a high GPA. The basic dilution effect predicts less extreme predictions when nondiagnostic information (e.g., the student describes himself as a cheerful person) is included with the diagnostic information. Despite an unusually large sample, a strong manipulation, and the use of stimulus sampling, results showed no evidence for dilution in GPA predictions. Reasons for the failure to replicate under optimal conditions are discussed. Practitioner points • Here Early research showed that nondiagnostic information may dilute predictions of student GPA. • Our study failed to replicate this effect, using a much larger sample and a more appropriate research design. • The dilution effect is not as robust as has been claimed, and its implications for selection remain unclear.
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Cultural psychological research has compellingly demonstrated that reliable East-West differences exist in basic cognitive styles: in contrast to the analytic, focal, linear thinking prevalent in the West, East Asians prefer to engage in more holistic, contextual, and intuitive thinking. However, despite the consensus on these cultural differences in thinking style, the literature on cross-cultural variation in actual cognitive biases is far more equivocal. The Fundamental Attribution Error (and by extension the Ultimate Attribution Error) has received the most attention among cognitive biases in the cultural arena; multiple studies have shown both evidence for cultural differences and evidence for universality. Similarly equivocal findings have emerged for other cognitive biases like the hindsight bias, positive illusions, and social exchange. Error Management Theory offers to reconcile this paradox of why consistent variation in thinking style do not necessarily lead to similarly consistent differences in cognitive biases; different mechanisms drive preferences (i.e., for how to think) versus actual behaviors (i.e., involving judgments/decisions). While different features of the physical environment likely gave rise to differences in preferences, pressures from the social environment likely pushed cognitive processing in common judgment tasks (like inferring another person’s mind or one’s own) in similar directions.
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We experimentally examine the joint effects of boilerplate disclosure and text markup (i.e., displaying tracked changes from a prior period) on the judgments of both novice and experienced users of financial information. Our study responds to regulators' concerns about the effects of boilerplate disclosure on investor judgment and their calls to leverage technology in improving disclosure usefulness. We manipulate the presence of boilerplate (higher versus lower) and text markup (markup versus no markup) in sequential corporate disclosures, and examine participants' sensitivity to diagnostic information about the firm's financial performance. Using psychology theory on the dilution effect, we predict that boilerplate will have a greater impact in the absence of markup, and markup's positive effect on sensitivity to diagnostic information will be stronger in disclosures with higher boilerplate. Our findings are consistent with this prediction. We also find that experienced users have greater sensitivity overall to diagnostic information and that markup increases novices' (but not experienced users') sensitivity to diagnostic information. Our findings extend theory on potential remedies to the dilution effect and are potentially useful to regulators as they consider improving the usefulness of corporate disclosure.
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This paper investigates the potential of using a frequency response mode to reduce the dilution effect of non-diagnostic evidence on auditors' fraud risk judgments. In two experiments, we test one hypothesis and examine a research question related to the dilution effect where response mode (frequency versus probability) and type of non-diagnostic or irrelevant information are manipulated between-participants. Results of the hypothesis tests show that auditors' fraud risk judgments demonstrate a significantly lower dilution effect when they evaluate diagnostic and non-diagnostic or irrelevant evidence using a frequency response mode, as compared to the probability response mode; this effect is most pronounced when auditors are provided with favorable non-diagnostic or irrelevant evidence. JEL Classifications: M4; M40; M420. Data Availability: Summary data are available from the authors upon request.
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Combining the English School of International Relations and the study of grand strategy decision-making processes, this article investigates how dynamic density – growing volume, velocity, and diversity of interactions within international society – alters states’ strategy formation processes. By contrasting the perspectives of structural realism and the English School on the role of dynamic density in world politics, the piece illustrates the strategist’s dilemma: as global dynamic density in the international society increases, the ability of great powers to formulate coherent grand strategies and policies potentially decreases. Specifically, it contends that growing global dynamic density generates processual and substantive fragmentation in strategy formation. Building on a large body of elite interviews, US policy toward China – and the so-called US ‘rebalance’ to Asia – is used as a probability probe of the central idea of the strategist’s dilemma. In conclusion, we contrast our findings with complex interdependence theory and examine their implications for ‘great power management’ (GPM) as a primary institution of international society. We argue that, by generating processual and substantive fragmentation in strategy formation, global dynamic density complicates GPM by hindering the capacity of great powers to manage and calibrate the competitive and cooperative dynamics at play in a bilateral relationship.
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In economics the use of psychological assumptions other than rationality to make predictions about organizational or system behaviour is rare, although the company is quite good (Keynes, 1936; Nelson and Winter, 1982; Simon, 1982; Williamson, 1975, 1985). From an empiricist’s view-point the dearth of research using alternative psychological assumptions is disappointing since there is massive evidence that individuals deviate from rationality. Furthermore, these deviations are systematic — the errors tend to be in the same direction — which implies that non-rational behaviour is often not random but predictable. However, to be fair, incorporating assumptions other than rationality has its costs. Rational models tend to be mathematically elegant and yield precise predictions, while behavioural models tend to be more complicated and yield vague predictions. Richard Thaler (1992, p. 198) sums up the tradeoff succinctly: ‘Would you rather be elegant and precisely wrong, or messy and vaguely right?’
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In dieser Abhandlung wird die Frage behandelt, wie Konsumenten auf Produktmerkmale reagieren, die für sie leicht durchschaubar nur in anderen Bereichen einen Nutzen stiften, aber keinen Nutzen im beworbenen Produkt aufweisen (z.B. echtes Gold in einer Seife, Wellnessfrüchte in einer Marmelade, Diamantenstaub in einem Nagelhärter). Wir bezeichnen solche Attribute als Imply-Benefit-Attribute und erörtern auf Basis von Konsumentenverhaltenstheorien und elf Experimenten deren Wirkung. Das zentrale Ergebnis lautet, dass derartige Produktmerkmale eine positive Wirkung aufweisen, es sei denn, hoch involvierte Konsumenten könnten dadurch von der Verarbeitung anderer starker Kaufargumente abgelenkt werden.
Despite a high drinkable quality, many people avoid tap water because of vague anxiety about its safety. Conjoint analysis (CA) was conducted to determine what factors are considered important for consumers' selection of drinking water. The information provision effect was also investigated inside CA profiles using different model equations. Results indicate that the perception of the safety of tap water was much lower than that of other waters. Higher levels of water hardness and cancer risk negatively influenced selection of drinking water, while third-party certifications about taste and safety positively impacted it. When cancer risk was shown in a CA profile, the weight given to other attributes decreased. Among different sociodemographic groups, gender was important in establishing drinking water preferences with men paying less attention to the benefits of water-dispensers and certifications from third parties. Besides, age also has some influence on drinking water selection. People's consciousness of taste, safety, cost, and handling for drinking water were assessed using an analytic hierarchy process and the scores were incorporated in a CA equation. The results suggest that improving people's perceptions of the taste and safety of tap water can promote consumers' selection of tap water as drinking water.
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Shifts in the global economy have placed more pressure on the decisions of employees, managers, and CEOs than ever before. At the same time, the proliferation of technology in the workplace has become ubiquitous. Fortunately, the assessment center method is evolving alongside these other trends. With just a few modifications to existing assessment center simulations, we can use newer technology to capture previously difficult to observe behaviors that tap directly into candidate’s decision making processes. By combining passive data logging of key strokes and mouse clicks, eye tracking, and physiological responses such as skin conductivity, we are able to capture behaviors in real time that can be used to supplement traditional assessor ratings. Doing so allows assessors to compile a more accurate and holistic summary of a candidate’s performance. This wealth of new behavioral information has implications for high stakes hiring decisions as well as targeted training and development.
Article
Lay judges’ decision-making process in the determination of appropriate punishment appears to be based on their assessment of the seriousness of the crime; this indicates that legal sentences are being decided subjectively, which can be problematic. For instance, judgments can sometimes be made on the basis of irrelevant and therefore improper, information. Ideally, such information would be disregarded when considering appropriate punishment in a real court. Thus, the aim of this study was to determine whether information that is irrelevant to a criminal case can influence Japanese lay judges’ determination of an appropriate punishment. Our study used a fictional case study and a questionnaire to assess whether Japanese participants were influenced by exposure to irrelevant information. The results of two experiments consistently showed that irrelevant information distorts the inner subjective balance between the severity of punishment and the seriousness of the crime and may even influence the decision-making process that lay judges engage in when determining offenders’ punishment. We suggest reasons why this influence might affect decision-making and discuss whether the influence of improper information can be consciously disregarded.
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This eagerly awaited volume presents Anderson's cumulative progress in unified social psychology. The research is grounded in the three fundamental laws of information integration theory. Research shows these laws to apply to topics in social and personality psychology such as person cognition, attitudes, moral cognition, social development, group dynamics and self-cognition. This definitive work will broaden the appreciation of Anderson's unique treatment of psychological processes.
Chapter
Celebrity endorsement is not new. We only need to turn to our TV screens to see one in five ads featuring the hottest celebrity of the month (Solomon, 2009). In fact, the use of celebrities as endorsers appears to be on the rise with 14 percent of advertisements in America featuring a celebrity, 24 percent in India and 45 percent in Taiwan (New York Times, 2008). The collaboration between brands and celebrities is such a common feature in the contemporary marketplace, that we see many celebrities often becoming the face, or image, not only of consumer products and brands, but of organisations themselves. In Australia, for example, John Travolta is the Ambassador for Qantas airline, Hugh Jackman lends his image to Lipton Ice Tea and Nicole Kidman supports Swisse multivitamins. Research shows that celebrities are an asset to any brand as they are able to positively affect stock returns (Agrawal and Kamakura, 1995; Marthur, Marthur and Rangan, 1997).
Article
Purpose – The purpose of this paper is to review the extensive and wide‐ranging published literature on the skills needed to get your point across effectively and succeed in the art of persuasion. It provides a structured, evidence‐based framework of learnable interpersonal skills. This framework can be used in training and development to describe current thinking and best practice in the essential skills needed to persuade others. It can be used by training and development professionals to help those they work with reflect on previous attempts at persuasion and prepare for future ones. It can also be used in training and development work to analyse and give feedback on role‐plays and presentations. The use of a structured, standardised and evidenced‐based framework increases the reliability and validity of the assessment process and, inconsequence, improves the quality of feedback. Design/methodology/approach – The article begins by looking at previous research by the author showing that the frequency with which people at work use six influence strategies, and combine them to form various styles, is related to a variety of contextual variables. However, it concludes that, while a focus on strategies and styles, and their appropriateness to particular contexts, has much merit, it is inevitably limited. In particular, it lacks specificity and any notion of quality. The concept of “skills” overcomes such limitations and provides important additional insights, particularly when focusing on the skills involved in using “reason”, the most frequently used and least context‐specific of the six influence strategies, to convince other people at work. Skills are defined as abilities, expertise or proficiency acquired through learning or training. The skills described herein are “interpersonal” skills or skills that people need to interact effectively with others. Findings – Seven skills people need to get their point across effectively and be successful in the art of persuasion are identified: be clear about “who”, “what” and “why”; target your case on the other person; search for common ground; keep it simple; appeal to “head” and “heart”; be calm and confident; and make it interactive. Originality/value – The originality and value of this paper lies in the way in which it reviews previous theory and research on interpersonal influence, identifies seven specific skills from this literature review and provides a structured, standardised and evidence‐based framework of learnable skills. These findings have implications for anyone who needs to get their point across effectively and succeed in the art of persuasion, as well as training and development professionals working in this area. The conclusions complement other research carried out by the author and published in a previous edition of Industrial and Commercial Training, showing that influencing behaviour varies in different contexts and arguing that the art of successful influence involves using strategies and styles appropriate to the context.
Article
Two experiments are reported that evaluate predictions derived from the sample space framework of probability judgment, according to which both accuracy and error in judgments can be explained in terms of the sets of information, or sample spaces, on which they are based. Participants judged probabilities concerning fictitious individuals about whom a small amount of information was provided. The probability judgments took the form p(AIB), for which the set of B's delineates the appropriate sample space and the set of A's delineates the inappropriate sample space. The accessibility of the sets was manipulated by having participants explicitly describe typical instances from the applicable sets (Experiment 1) or by priming the relevant categories (Experiment 2). Results showed that judgments of conditional probabilities were more accurate when the appropriate set B was made accessible than when the in appropriate set A was made accessible.
Article
This study examines the effect of irrelevant information presented in marketing communications by a celebrity co-branding partner on consumer judgments of a partner brand. Three experimental conditions manipulate the relevancy of information: relevant information, irrelevant information, and relevant plus irrelevant information. Findings from this study suggest that when a celebrity co-branding partner does not provide information about the partner brand nor brand benefits, consumer judgments in the ability of the partner brand to deliver benefits, their purchase intent and their match-up perceptions become less positive. Consumer brand benefit beliefs and purchase intentions show evidence of a dilution effect only when consumers perceive a mismatch between the celebrity and brand and when presented with irrelevant information supplied by a celebrity in addition to relevant brand information. Interestingly, not only the relevant celebrity characteristics associated with the brand but also the irrelevant information provided by the celebrity in the advertisement influence perceptions of match-up or congruence. Brand managers should ensure a celebrity co-branding partner does not provide irrelevant brand information within advertisements to avoid brand benefit belief, purchase intent and match-up dilution.
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The present research investigated the relationship between stereotypical and individuating information in judgmental tasks. In particular, it was hypothesized that, in addition to considering the nature of the individuating information presented to subjects, it is also important to investigate how the credibility of the source of this information can affect stereotype dilution. Extending ideas from the literature on persuasion, the present results supported the prediction that subjects differentiate between high-and low-credibility sources only when they provide stereotype-disconfirming individuating information. They did not, however support the contention that stereotype dilution is invariably mediated by a reliance on the representativeness heuristic. These findings are considered in the wider context of cognitive approaches to stereotyping and stereotype change.
Article
Existing models of impression formation and stereotyping focus on the fit between data and theory, or between individuating and categorical information. This fit is supposed to be determined by cognitive and motivational factors. It is proposed that current perspectives on social judgment can be enriched by going beyond data and theory and adding a third aspect, the social judgeability of the target. First, this new approach is presented in its broad lines. Second, several ways to manipulate judgeability are suggested. Throughout the chapter, we build upon earlier work and provide new empirical evidence. Also, classic experiments are reinterpreted within this new framework which considers stereotypes as social explanations and not as errors or prejudices.
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This paper examines the impact of attribute presence/absence in choice experiments using covariance heterogeneity models and random coefficient models. Results show that attribute presence/absence impacts both mean utility (systematic components) and choice variability (random components). Biased mean effects can occur by not accounting for choice variability. Further, even if one accounts for choice variability, attribute effects can differ because of attribute presence/absence. Managers who use choice experiments to study product changes or new variants should be cautious about excluding potentially essential attributes. Although including more relevant attributes increases choice variability, it also reduces bias.
Article
This study explored competing normative interpretations of the dilution effect: the tendency for people to underutilize diagnostic evidence in prediction tasks when that evidence is accompanied by irrelevant information. From the normative vantage point of the intuitive statistician, the dilution effect is a judgmental bias that arises from the representativeness heuristic (similarity-matching of causes and effects). From the normative prospective of the intuitive politician, however, the dilution effect is a rational response to evidence presented in a setting in which Gricean norms of conversation are assumed to hold. The current experiment factorially manipulated conversational norms, the degree to which diagnostic evidence was diluted by irrelevant evidence, and the accountability of subjects for their judgments. Accountable subjects demonstrated a robust dilution effect when conversational norms were explicitly primed as well as in the no-priming control condition, but no dilution when conversational norms were explicitly deactivated. Non-accountable subjects demonstrated the dilution effect across norm activation conditions, with the strongest effect under the activation of conversational norms. Although the results generally support the conversational-norm interpretation of dilution, the significant dilution effect among non-accountable subjects in the norm-deactivated condition is more consistent with the judgmental-bias interpretation.
Article
This chapter advances to a testable middle-range theory predicated on the politician metaphor: the social contingency model of judgment and choice. This model does not map neatly in any of the traditional levels of analysis: the individual, the small group, the organization, and political system. The unit of study is the individual in relation to these social milieux. The model borrows, qualifies, and elaborates on the cognitive miser image of the thinker that has been so influential in experimental work on social cognition. The model adopts the approval and status-seeker image of human nature that has been so influential in role theory, symbolic interactionism, and impression management theory. The model draws on sociological and anthropological theory concerning the necessary conditions for social order in positing accountability to be a universal feature of natural decision environments. The social contingency model is not tightly linked to any particular methodology. The theoretical eclecticism of the model demands a corresponding commitment to methodological eclecticism. The social contingency model poses problems that cross disciplinary boundaries, and that require a plurality of methodologies. The chapter ends with considering the potential problem of proliferating metaphors in social psychological theory.
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Language attitude study has an extensive research tradition rooted in an array of disciplines. The social psychology of language, sociology of language, sociolinguistics, anthropological linguistics, communication, and discourse analysis have all made contributions. The aim of this article is to overview both the past and recent history of language attitude research as well as indicated some new affective and motivational directions for the future. In this context, we also offer a heuristic schema as well as generalizations for the language attitudes process.
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The impact of diagnostic information on judgments and in decision making is often reduced when additional, nondiagnostic information is presented. This article argues that the diluting impact of nondiagnostic information results in part from rules of everyday communication,which usually grant relevance to presented information.In an experimental test, participants were presented with positive or negative information about a product.Positive diagnostic information resulted in more favorable judgments than negative diagnostic information. This impact of diagnostic information was diluted when nondiagnostic information was added. Most important, the dilution effect was not observed when the applicability of the conversation was experimentally called into question.
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Two experiments examined the interplay of consensus information and situational information in shaping trait inferences. Participants read scenarios that described a target person's behavior (e.g., Matt volunteered to clean up after a park tour) and made trait inferences (e.g., perceived helpfulness) about the target and relevant population (e.g., other members of the park tour). We orthogonally manipulated the level of consensus for the target's behavior (high vs. low) and whether or not participants were given specific information that could comprise a viable situational explanation for the behavior (e.g., volunteers were offered an attractive gift certificate). The key prediction was that the two factors would interact in determining trait inferences about the target. As expected, when the specific situational information was mentioned in the scenario, participants used consensus information to modulate trait inferences about the target; when the specific situational information was not mentioned, participants tended to show consensus neglect for target inferences and primarily used consensus information to modulate inferences about the population. The findings are discussed in relation to two issues: (1) understanding consensus neglect, and (2) the interaction of covariation and mechanism approaches to causal attribution.
Article
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.
Article
Previous research examining stereotype dilution had illustrated the importance of task instructions (Neuberg & Fiske, 1987), outcome dependence (Erber & Fiske, 1984; Neuberg & Fiske, 1987), and information about the target individual (Krueger & Rothbart, 1988; Macrae et al., 1992). This paper presents two studies investigating the stability of an occupational stereotype under different environmental conditions. Specifically it examines the maintenance and dilution of stereotypical judgements about licensees (pub managers) amongst undergraduate students. The results of the first study provide evidence for a context-free stereotype about public house licenses. However, results from the second study suggest that this stereotype is influenced by environmental conditions. That is, subjects do not simply continue to stereotype regardless of context, rather, under certain environmental conditions they individuate and reduce the impact of their stereotypical judgements. Implications for stereotype research and the role of environmental variables are made.
Article
The objective of this paper is to show opportunities for integrating psychological and economics research in auditing. For this purpose, auditing research that employs both the methodologies of experimental psychology and experimental economics is collectively reviewed. The review is structured along three fundamental research questions: (1) Are auditors prone to biases; (2) what are the consequences of biased judgment in auditing; and (3) do features of the audit environment interact with the biased judgment? While both the research approach of experimental psychology and experimental economics are employed for addressing these resesarch questions, both approaches differ in their focus and their implementation. This review highlights these differences, outlines the main findings and identifies future research opportunities.
Article
Previous research on auditors' processing of nondiagnostic evidence has demonstrated the existence of a dilution effect - the tendency to underreact to diagnostic information when accompanied by nondiagnostic information. Prior audit studies find that accountability, a prominent feature in audit settings, does not affect the magnitude of the dilution effect exhibited by auditors. Based on more recent theories avout accountability, this line of research is extended by exploring whether (1) the dilution effect previously identified is a robust phenomenon that can be replicated, (2) accountability has an impact on both the frequency and magnitude of dilution effect, and (3) the impact of accountability on both the frequency and magnitide of dilution effect is conditional on the degree of accountability experienced by the participants through various reporting levels. The experimental results from a sample of internal auditors provide evidence supporting the first two propositions; however, the results related to reporting levels are not significant. A discussion of the implications of these findings for audit research and practice follows.
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Investors have asserted that, too often, firms are not disclosing enough information for them to appropriately allocate their investment resources (e.g., Cheney 2008; FASB 2008; Desir et al. 2010). One approach would be for standard setters to lower a disclosure threshold for bad news in order to warn investors of more potential losses. Ordinarily, one would expect that adding more potential losses to a disclosure, would, if anything, add to investors’ perceptions of the risk of future loss. However, we examine two ways in which such a disclosure requirement can actually lower some investors’ risk assessments. The debate over the FASB’s recent proposal to lower the disclosure threshold for a firm’s litigation risk disclosures provides us with a timely setting to examine these two unintended consequences on different types of investors. First, lowering a disclosure threshold naturally means including additional potential losses in the disclosure that were previously thought too inconsequential to disclose. If some investors allow the low-probability losses to dilute, rather than add to, the more probable losses in their overall perceptions, then the requirement to disclose more bad news could actually lead to more favorable perceptions of litigation risk. Consistent with prior research on the dilution effect, we find that potential investors are the most susceptible to this effect. Second, since lowering the threshold likely changes the overall composition of the disclosure by adding low-probability losses, firms could adopt a “laundry list” strategy that characterizes the entire disclosure as unimportant, presenting the lowest risks most saliently, using compliance with the low threshold as a plausible reason for giving a lengthy disclosure of generally unimportant risks. Our experimental findings suggest that this strategy can be persuasive. Our findings have important implications for standard setters, investors, auditors, and researchers.
Article
Expert psychological testimony in recent sex discrimination and sexual harassment cases has presented fact finders with a conceptual framework for understanding the antecedents and consequences of gender stereotyping. In this article, we focus on perhaps the most scientifically complex aspect of research on gender stereotyping—namely, the role that individuating information plays in stereotypical thinking. Although a preponderance of evidence suggests that stereotypes are likely to influence impressions and evaluations when perceivers have either minimal or ambiguous information about another person, there is the potential for attorneys and even some expert witnesses to misconstrue this aspect of the scientific data base. We review briefly pertinent findings on the relationship between stereotypes and individuating information, and discuss some of the reasons why this evidence could be misrepresented.
Chapter
This chapter discusses the social psychologists study “top of the head” phenomena in their experimental investigations. Attention within the social environment is selective. It is drawn to particular features of the environment either as a function of qualities intrinsic to those features (such as light or movement) or as a function of the perceiver's own dispositions and temporary need states. These conditions are outlined in the chapter. As a result of differential attention to particular features, information about those features is more available to the perceiver. Relative to the quantity of information retained about other features, more is retained about the salient features. When the salient person is the self, the same effects occur, and the individual is also found to show more consistency in attitudes and behaviors. These processes may occur primarily in situations which are redundant, unsurprising, uninvolving, and unarousing. They seem to occur automatically and substantially without awareness, and as such, they differ qualitatively from the intentional, conscious, controlled kind of search which characterizes all the behavior.
Article
For both people and machines, each in their own way, there is a serious problem in common of making sense out of what they hear, see, or are told about the world. The conceptual apparatus necessary to perform even a partial feat of understanding is formidable and fascinating. Our analysis of this apparatus is what this book is about. —Roger C. Schank and Robert P. Abelson from the Introduction (http://www.psypress.com/scripts-plans-goals-and-understanding-9780898591385)
Article
This paper outlines a classificatory theory of cognitive similarity and compares it to feature approaches. The theory assumes that similarity is a function of the number of classes contained in the universe referred to in the judgments and the number of elements contained in the class defined by the two comparison stimuli. The theory is tested in a number of studies in which verbal stimuli are used. Most of the experiments concern context effects predicted by the theory. An empirical comparison is made between the classificatory theory and a feature theory. It is argued that the classificatory theory accounts for some of the data more easily than a feature approach does. Some implications for the use of similarity data in multidimensional scaling are also discussed.
Article
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.
Article
Questions the metric and dimensional assumptions that underlie the geometric representation of similarity on both theoretical and empirical grounds. A new set-theoretical approach to similarity is developed in which objects are represented as collections of features and similarity is described as a feature-matching process. Specifically, a set of qualitative assumptions is shown to imply the contrast model, which expresses the similarity between objects as a linear combination of the measures of their common and distinctive features. Several predictions of the contrast model are tested in studies of similarity with both semantic and perceptual stimuli. The model is used to uncover, analyze, and explain a variety of empirical phenomena such as the role of common and distinctive features, the relations between judgments of similarity and difference, the presence of asymmetric similarities, and the effects of context on judgments of similarity. The contrast model generalizes standard representations of similarity data in terms of clusters and trees. It is also used to analyze the relations of prototypicality and family resemblance. (39 ref) (PsycINFO Database Record (c) 2012 APA, all rights reserved)
Article
Considers that intuitive predictions follow a judgmental heuristic-representativeness. By this heuristic, people predict the outcome that appears most representative of the evidence. Consequently, intuitive predictions are insensitive to the reliability of the evidence or to the prior probability of the outcome, in violation of the logic of statistical prediction. The hypothesis that people predict by representativeness was supported in a series of studies with both naive and sophisticated university students (N = 871). The ranking of outcomes by likelihood coincided with the ranking by representativeness, and Ss erroneously predicted rare events and extreme values if these happened to be representative. The experience of unjustified confidence in predictions and the prevalence of fallacious intuitions concerning statistical regression are traced to the representativeness heuristic.
Article
This paper explores a judgmental heuristic in which a person evaluates the frequency of classes or the probability of events by availability, i.e., by the ease with which relevant instances come to mind. In general, availability is correlated with ecological frequency, but it is also affected by other factors. Consequently, the reliance on the availability heuristic leads to systematic biases. Such biases are demonstrated in the judged frequency of classes of words, of combinatorial outcomes, and of repeated events. The phenomenon of illusory correlation is explained as an availability bias. The effects of the availability of incidents and scenarios on subjective probability are discussed.
Article
This article described three heuristics that are employed in making judgements under uncertainty: (i) representativeness, which is usually employed when people are asked to judge the probability that an object or event A belongs to class or process B; (ii) availability of instances or scenarios, which is often employed when people are asked to assess the frequency of a class or the plausibility of a particular development; and (iii) adjustment from an anchor, which is usually employed in numerical prediction when a relevant value is available. These heuristics are highly economical and usually effective, but they lead to systematic and predictable errors. A better understanding of these heuristics and of the biases to which they lead could improve judgements and decisions in situations of uncertainty.
Article
Considering the ubiquity of psychological similarity in many areas of cognition research, a common procedure, the transfer experiment, will unite them and so have the areas properly conceptualized in an integrated manner. Secondly, 4 conceptions of psychological similarity are defined in terms of common environmental properties, common responses, primary stimulation gradients, and assignment to a common category. The last of these 4 definitions appears to be of greatest applicability. Experimental implications are explored, and further work based on defining similarity in terms of assignment to a common category is proposed. 32 references.
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