Hartmut Blank - Academia.edu (original) (raw)

Papers by Hartmut Blank

Research paper thumbnail of How to protect eyewitness memory against the misinformation effect: A meta-analysis of post-warning studies

Journal of Applied Research in Memory and Cognition, 2014

ABSTRACT Four decades of research and hundreds of studies speak to the power of post-event misinf... more ABSTRACT Four decades of research and hundreds of studies speak to the power of post-event misinformation to bias eyewitness accounts of events (see e.g. Loftus’ summary, 2005). A subset of this research has explored if the adverse influence of misinformation on remembering can be undone or at least reduced through a later warning about its presence. We meta-analyzed 25 such post-warning studies (including 155 effect sizes) to determine the effectiveness of different types of warnings and to explore moderator effects. Key findings were that (1) post-warnings are surprisingly effective, reducing the misinformation effect to less than half of its size on average. (2) Some types of post-warning (following a theoretical classification) seem to be more effective than others, particularly studies using an enlightenment procedure ( Blank, 1998). (3) The post-warning reduction in the misinformation effect reflects a specific increase in misled performance (relative to no warning), at negligible cost for control performance. We conclude with a discussion of theoretical and practical implications.

Research paper thumbnail of Das Paradigma der minimalen Gruppen

Das Paradigma der minimalen Gruppen war in den letzten vier Jahrzehnten das dominierende Forschun... more Das Paradigma der minimalen Gruppen war in den letzten vier Jahrzehnten das dominierende Forschungsparadigma in der Forschung zum Phänomen "soziale Diskriminierung". Daher wird diesem Paradigma hier auch ein eigenes Stichwort gewidmet. Zunächst werden die Grundidee des Forschungsparadigmas und die klassische erste Untersuchung von beschrieben. Es folgen ein Überblick über Ergebnisse von Nachfolgestudien und eine Darstellung verschiedener auf das Paradigma bezogener Kritikpunkte. Schließlich werden das konkrete experimentelle Vorgehen bei Untersuchungen mit dem Paradigma der minimalen Gruppen und traditionelle und neuere Auswertungsverfahren der erhobenen Daten vorgestellt.

Research paper thumbnail of Looking back on the London Olympics: Independent outcome and hindsight effects in decision evaluation

British Journal of Social Psychology, 2015

Outcome bias and hindsight bias are related, but how exactly? To remedy theoretical ambiguity and... more Outcome bias and hindsight bias are related, but how exactly? To remedy theoretical ambiguity and non-existent directly relevant empirical research, we contrast an older idea (Baron & Hershey, 1988, J. Pers. Soc. Psychol., 54, 569) that sees outcome bias as partly mediated through hindsight bias with the idea that the two biases independently affect decision evaluations. In an Internet study of retrospections on the 2012 London Olympics, evaluations of the Games' success and its foreseeability had independent effects on evaluations of the International Olympic Committee's decision to award the Olympics to London; there was no evidence of mediation. Further theoretical discussion emphasizes the need to distinguish between a holistic assessment of decisions and a more specific assessment of the decision-making process in future outcome bias research.

Research paper thumbnail of Reale Gruppen im Paradigma der minimalenGruppen

Experimental Psychology, 2001

Research paper thumbnail of Kolumnentitel: DETERMINANTEN POLITISCHER PARTEIENPRÄFERENZEN

Research paper thumbnail of Richtlinien zur Gestaltung von schriftlichen Referaten, Hausarbeiten und Praktikumsberichten

Research paper thumbnail of Persönlichkeitsmerkmale, soziale Überzeugungen und politische Parteienpräferenzen: Eine Internetbefragung zur Bundestagswahl 2002= Personality traits, social beliefs, and political party preferences: An internet survey on the occasion of the German parliamentary election 2002

Research paper thumbnail of Entscheidungsprozesse im Falschinformationsparadigma

Research paper thumbnail of Self-Monitoring and Linguistic Adaptation

Social Psychology, 2012

This article explores the role of self-monitoring in the adaptation to different linguistic envir... more This article explores the role of self-monitoring in the adaptation to different linguistic environments (dialects and foreign languages). An internet study (N = 505) found the motivation and ability of speakers of local German dialects to switch to the German high language (as measured by a specifically developed scale) to be moderately related (r = .24) to their self-monitoring scores.

Research paper thumbnail of Hindsight Bias and Causal Attribution

Social Psychology, 2008

Hindsight bias describes characteristic changes in the perceptions of events or facts once their ... more Hindsight bias describes characteristic changes in the perceptions of events or facts once their outcomes are known. This article focuses on one important facet of this, named creeping determinism, denoting enhanced hindsight perceptions of the inevitability of event outcomes. We suggest a systematic link between the literatures on causal attribution and hindsight bias/creeping determinism and introduce a comprehensive causal model

Research paper thumbnail of Prejudiced Behavior Toward Lesbians and Gay Men

Social Psychology, 2009

Investigations of prejudice toward lesbians and gay men mostly rely on self-report questionnaires... more Investigations of prejudice toward lesbians and gay men mostly rely on self-report questionnaires and rarely make use of indirect, behavioral measures. This field experiment investigated helping in an everyday face-to-face situation as an indicator of discrimination. Members of the public (N = 240) were approached by a person asking for 10 pence for a parking meter. The requestor wore either

Research paper thumbnail of «Es musste eigentlich so kommen»: Rückschaufehler bei der Bundestagswahl 1998

Zeitschrift für Sozialpsychologie, 2000

Zusammenfassung: Psychologieanfänger/innen an der Universität Leipzig gaben drei Monate vor der B... more Zusammenfassung: Psychologieanfänger/innen an der Universität Leipzig gaben drei Monate vor der Bundestagswahl 1998 Prognosen für den Stimmenanteil verschiedener Parteien und für die Regierungsbildung ab. Die erinnerten Prognosen einen Monat nach ...

Research paper thumbnail of Cognitive Process Models of Hindsight Bias

Research paper thumbnail of Hindsight Bias: On Being Wise After the Event

Social Cognition, 2007

... Social Cognition, 25(1), 165–184. Musch, J., & Wagner T. (2007). Did everybody kn... more ... Social Cognition, 25(1), 165–184. Musch, J., & Wagner T. (2007). Did everybody know it all along? A review of individ-ual differences in hindsight bias. ... Social and Personality Psychology Compass 5:4, 180-193. [CrossRef] 3. Alex Soojung-Kim Pang. 2010. ...

Research paper thumbnail of Entscheidungsprozesse im Falschinformationsparadigma

Psychologische Rundschau, 2004

Research paper thumbnail of False Memory ≠ False Memory: DRM Errors Are Unrelated to the Misinformation Effect

PLoS ONE, 2013

The DRM method has proved to be a popular and powerful, if controversial, way to study &a... more The DRM method has proved to be a popular and powerful, if controversial, way to study 'false memories'. One reason for the controversy is that the extent to which the DRM effect generalises to other kinds of memory error has been neither satisfactorily established nor subject to much empirical attention. In the present paper we contribute data to this ongoing debate. One hundred and twenty participants took part in a standard misinformation effect experiment, in which they watched some CCTV footage, were exposed to misleading post-event information about events depicted in the footage, and then completed free recall and recognition tests. Participants also completed a DRM test as an ostensibly unrelated filler task. Despite obtaining robust misinformation and DRM effects, there were no correlations between a broad range of misinformation and DRM effect measures (mean r = -.01). This was not due to reliability issues with our measures or a lack of power. Thus DRM 'false memories' and misinformation effect 'false memories' do not appear to be equivalent.

Research paper thumbnail of Hindsight bias in political elections

Memory, 2003

Two studies on political hindsight bias were conducted on the occasions of the German parliament ... more Two studies on political hindsight bias were conducted on the occasions of the German parliament election in 1998 and the Nordrhein-Westfalen state parliament election in 2000. In both studies, participants predicted the percentage of votes for several political parties and recalled these predictions after the election. The observed hindsight effects were stronger than those found in any prior study on political elections (using percentage of votes as the dependent variable). We argue that the length of the retention interval between original judgement and recollection is mainly responsible for this difference. In our second study, we investigated possible artifacts in political hindsight biases using a control-group design where half of the participants recalled their predictions shortly before or after the election. Hindsight bias was preserved, reinforcing the results of earlier studies with non-control-group designs. Finally, we discuss the possibility that the hindsight experience (in political judgement and in general) actually consists of three different, partly independent components.

Research paper thumbnail of Uniforms affect the accuracy of children's eyewitness identification decisions

Journal of Investigative Psychology and Offender Profiling, 2010

Page 1. Uniforms Affect the Accuracy of Children's Eyewitness Identification Dec... more Page 1. Uniforms Affect the Accuracy of Children's Eyewitness Identification Decisions JOSEPH A. LOWENSTEIN, HARTMUT BLANK* and JAMES D. SAUER University of Portsmouth, Portsmouth, Hampshire, UK Abstract A ...

Research paper thumbnail of Cognitive consistency and the formation of interpersonal attitudes: Cognitive balance affects the encoding of social information

Journal of Experimental Social Psychology, 2005

Three studies investigated the role of cognitive balance in the formation of interpersonal attitu... more Three studies investigated the role of cognitive balance in the formation of interpersonal attitudes. Experiment 1 found evidence for balanced triads when participants Wrst formed an attitude about one person, and then learned about this person's sentiments about another individual. Interestingly, balanced triads were obtained for both explicitly and implicitly assessed attitudes. Experiment 2 indicated that the pattern of interpersonal relations does not result in balanced triads, when participants Wrst learn about the relationship between two neutral individuals, and then receive evaluative information about one of the two individuals. In this case, observed sentiments and evaluative information aVected attitudes in an additive rather than interactive manner. Experiment 3 replicated these Wndings by manipulating valence, observed sentiments, and order of information acquisition in a single study. Taken together, these results suggest that cognitive balance inXuences the encoding of social information, rather than the retroactive construal of evaluative judgments. 

Research paper thumbnail of When linking is stronger than thinking: Associative transfer of valence disrupts the emergence of cognitive balance after attitude change

Journal of Experimental Social Psychology, 2009

The present research investigated the role of cognitive balance vs. associative transfer of valen... more The present research investigated the role of cognitive balance vs. associative transfer of valence in attitude change. Participants first formed positive or negative attitudes toward several source individuals. Subsequently, participants were shown source-target pairs along with information about the source-target relationship ('likes'/'dislikes'). Afterwards, participants' attitudes toward the sources were changed by means of information that was opposite to the initially induced attitude. In a control condition, initial source attitudes remained unqualified. Results in the control condition showed that initially formed attitudes and available relationship information produced target evaluations that were consistent with the notion of cognitive balance. However, when attitudes toward the sources changed, target evaluations directly matched attitudes toward individually associated sources, irrespective of the relation between source and target. These results suggest that associative transfer of valence can disrupt the emergence of cognitive balance after attitude change.

Research paper thumbnail of How to protect eyewitness memory against the misinformation effect: A meta-analysis of post-warning studies

Journal of Applied Research in Memory and Cognition, 2014

ABSTRACT Four decades of research and hundreds of studies speak to the power of post-event misinf... more ABSTRACT Four decades of research and hundreds of studies speak to the power of post-event misinformation to bias eyewitness accounts of events (see e.g. Loftus’ summary, 2005). A subset of this research has explored if the adverse influence of misinformation on remembering can be undone or at least reduced through a later warning about its presence. We meta-analyzed 25 such post-warning studies (including 155 effect sizes) to determine the effectiveness of different types of warnings and to explore moderator effects. Key findings were that (1) post-warnings are surprisingly effective, reducing the misinformation effect to less than half of its size on average. (2) Some types of post-warning (following a theoretical classification) seem to be more effective than others, particularly studies using an enlightenment procedure ( Blank, 1998). (3) The post-warning reduction in the misinformation effect reflects a specific increase in misled performance (relative to no warning), at negligible cost for control performance. We conclude with a discussion of theoretical and practical implications.

Research paper thumbnail of Das Paradigma der minimalen Gruppen

Das Paradigma der minimalen Gruppen war in den letzten vier Jahrzehnten das dominierende Forschun... more Das Paradigma der minimalen Gruppen war in den letzten vier Jahrzehnten das dominierende Forschungsparadigma in der Forschung zum Phänomen "soziale Diskriminierung". Daher wird diesem Paradigma hier auch ein eigenes Stichwort gewidmet. Zunächst werden die Grundidee des Forschungsparadigmas und die klassische erste Untersuchung von beschrieben. Es folgen ein Überblick über Ergebnisse von Nachfolgestudien und eine Darstellung verschiedener auf das Paradigma bezogener Kritikpunkte. Schließlich werden das konkrete experimentelle Vorgehen bei Untersuchungen mit dem Paradigma der minimalen Gruppen und traditionelle und neuere Auswertungsverfahren der erhobenen Daten vorgestellt.

Research paper thumbnail of Looking back on the London Olympics: Independent outcome and hindsight effects in decision evaluation

British Journal of Social Psychology, 2015

Outcome bias and hindsight bias are related, but how exactly? To remedy theoretical ambiguity and... more Outcome bias and hindsight bias are related, but how exactly? To remedy theoretical ambiguity and non-existent directly relevant empirical research, we contrast an older idea (Baron & Hershey, 1988, J. Pers. Soc. Psychol., 54, 569) that sees outcome bias as partly mediated through hindsight bias with the idea that the two biases independently affect decision evaluations. In an Internet study of retrospections on the 2012 London Olympics, evaluations of the Games' success and its foreseeability had independent effects on evaluations of the International Olympic Committee's decision to award the Olympics to London; there was no evidence of mediation. Further theoretical discussion emphasizes the need to distinguish between a holistic assessment of decisions and a more specific assessment of the decision-making process in future outcome bias research.

Research paper thumbnail of Reale Gruppen im Paradigma der minimalenGruppen

Experimental Psychology, 2001

Research paper thumbnail of Kolumnentitel: DETERMINANTEN POLITISCHER PARTEIENPRÄFERENZEN

Research paper thumbnail of Richtlinien zur Gestaltung von schriftlichen Referaten, Hausarbeiten und Praktikumsberichten

Research paper thumbnail of Persönlichkeitsmerkmale, soziale Überzeugungen und politische Parteienpräferenzen: Eine Internetbefragung zur Bundestagswahl 2002= Personality traits, social beliefs, and political party preferences: An internet survey on the occasion of the German parliamentary election 2002

Research paper thumbnail of Entscheidungsprozesse im Falschinformationsparadigma

Research paper thumbnail of Self-Monitoring and Linguistic Adaptation

Social Psychology, 2012

This article explores the role of self-monitoring in the adaptation to different linguistic envir... more This article explores the role of self-monitoring in the adaptation to different linguistic environments (dialects and foreign languages). An internet study (N = 505) found the motivation and ability of speakers of local German dialects to switch to the German high language (as measured by a specifically developed scale) to be moderately related (r = .24) to their self-monitoring scores.

Research paper thumbnail of Hindsight Bias and Causal Attribution

Social Psychology, 2008

Hindsight bias describes characteristic changes in the perceptions of events or facts once their ... more Hindsight bias describes characteristic changes in the perceptions of events or facts once their outcomes are known. This article focuses on one important facet of this, named creeping determinism, denoting enhanced hindsight perceptions of the inevitability of event outcomes. We suggest a systematic link between the literatures on causal attribution and hindsight bias/creeping determinism and introduce a comprehensive causal model

Research paper thumbnail of Prejudiced Behavior Toward Lesbians and Gay Men

Social Psychology, 2009

Investigations of prejudice toward lesbians and gay men mostly rely on self-report questionnaires... more Investigations of prejudice toward lesbians and gay men mostly rely on self-report questionnaires and rarely make use of indirect, behavioral measures. This field experiment investigated helping in an everyday face-to-face situation as an indicator of discrimination. Members of the public (N = 240) were approached by a person asking for 10 pence for a parking meter. The requestor wore either

Research paper thumbnail of «Es musste eigentlich so kommen»: Rückschaufehler bei der Bundestagswahl 1998

Zeitschrift für Sozialpsychologie, 2000

Zusammenfassung: Psychologieanfänger/innen an der Universität Leipzig gaben drei Monate vor der B... more Zusammenfassung: Psychologieanfänger/innen an der Universität Leipzig gaben drei Monate vor der Bundestagswahl 1998 Prognosen für den Stimmenanteil verschiedener Parteien und für die Regierungsbildung ab. Die erinnerten Prognosen einen Monat nach ...

Research paper thumbnail of Cognitive Process Models of Hindsight Bias

Research paper thumbnail of Hindsight Bias: On Being Wise After the Event

Social Cognition, 2007

... Social Cognition, 25(1), 165–184. Musch, J., & Wagner T. (2007). Did everybody kn... more ... Social Cognition, 25(1), 165–184. Musch, J., & Wagner T. (2007). Did everybody know it all along? A review of individ-ual differences in hindsight bias. ... Social and Personality Psychology Compass 5:4, 180-193. [CrossRef] 3. Alex Soojung-Kim Pang. 2010. ...

Research paper thumbnail of Entscheidungsprozesse im Falschinformationsparadigma

Psychologische Rundschau, 2004

Research paper thumbnail of False Memory ≠ False Memory: DRM Errors Are Unrelated to the Misinformation Effect

PLoS ONE, 2013

The DRM method has proved to be a popular and powerful, if controversial, way to study &a... more The DRM method has proved to be a popular and powerful, if controversial, way to study 'false memories'. One reason for the controversy is that the extent to which the DRM effect generalises to other kinds of memory error has been neither satisfactorily established nor subject to much empirical attention. In the present paper we contribute data to this ongoing debate. One hundred and twenty participants took part in a standard misinformation effect experiment, in which they watched some CCTV footage, were exposed to misleading post-event information about events depicted in the footage, and then completed free recall and recognition tests. Participants also completed a DRM test as an ostensibly unrelated filler task. Despite obtaining robust misinformation and DRM effects, there were no correlations between a broad range of misinformation and DRM effect measures (mean r = -.01). This was not due to reliability issues with our measures or a lack of power. Thus DRM 'false memories' and misinformation effect 'false memories' do not appear to be equivalent.

Research paper thumbnail of Hindsight bias in political elections

Memory, 2003

Two studies on political hindsight bias were conducted on the occasions of the German parliament ... more Two studies on political hindsight bias were conducted on the occasions of the German parliament election in 1998 and the Nordrhein-Westfalen state parliament election in 2000. In both studies, participants predicted the percentage of votes for several political parties and recalled these predictions after the election. The observed hindsight effects were stronger than those found in any prior study on political elections (using percentage of votes as the dependent variable). We argue that the length of the retention interval between original judgement and recollection is mainly responsible for this difference. In our second study, we investigated possible artifacts in political hindsight biases using a control-group design where half of the participants recalled their predictions shortly before or after the election. Hindsight bias was preserved, reinforcing the results of earlier studies with non-control-group designs. Finally, we discuss the possibility that the hindsight experience (in political judgement and in general) actually consists of three different, partly independent components.

Research paper thumbnail of Uniforms affect the accuracy of children's eyewitness identification decisions

Journal of Investigative Psychology and Offender Profiling, 2010

Page 1. Uniforms Affect the Accuracy of Children's Eyewitness Identification Dec... more Page 1. Uniforms Affect the Accuracy of Children's Eyewitness Identification Decisions JOSEPH A. LOWENSTEIN, HARTMUT BLANK* and JAMES D. SAUER University of Portsmouth, Portsmouth, Hampshire, UK Abstract A ...

Research paper thumbnail of Cognitive consistency and the formation of interpersonal attitudes: Cognitive balance affects the encoding of social information

Journal of Experimental Social Psychology, 2005

Three studies investigated the role of cognitive balance in the formation of interpersonal attitu... more Three studies investigated the role of cognitive balance in the formation of interpersonal attitudes. Experiment 1 found evidence for balanced triads when participants Wrst formed an attitude about one person, and then learned about this person's sentiments about another individual. Interestingly, balanced triads were obtained for both explicitly and implicitly assessed attitudes. Experiment 2 indicated that the pattern of interpersonal relations does not result in balanced triads, when participants Wrst learn about the relationship between two neutral individuals, and then receive evaluative information about one of the two individuals. In this case, observed sentiments and evaluative information aVected attitudes in an additive rather than interactive manner. Experiment 3 replicated these Wndings by manipulating valence, observed sentiments, and order of information acquisition in a single study. Taken together, these results suggest that cognitive balance inXuences the encoding of social information, rather than the retroactive construal of evaluative judgments. 

Research paper thumbnail of When linking is stronger than thinking: Associative transfer of valence disrupts the emergence of cognitive balance after attitude change

Journal of Experimental Social Psychology, 2009

The present research investigated the role of cognitive balance vs. associative transfer of valen... more The present research investigated the role of cognitive balance vs. associative transfer of valence in attitude change. Participants first formed positive or negative attitudes toward several source individuals. Subsequently, participants were shown source-target pairs along with information about the source-target relationship ('likes'/'dislikes'). Afterwards, participants' attitudes toward the sources were changed by means of information that was opposite to the initially induced attitude. In a control condition, initial source attitudes remained unqualified. Results in the control condition showed that initially formed attitudes and available relationship information produced target evaluations that were consistent with the notion of cognitive balance. However, when attitudes toward the sources changed, target evaluations directly matched attitudes toward individually associated sources, irrespective of the relation between source and target. These results suggest that associative transfer of valence can disrupt the emergence of cognitive balance after attitude change.