Michael R. Leippe

In search of reliable persuasion effects: III. The sleeper effect is dead. Long live the sleeper effect.

The sleeper effect in persuasion is a delayed increase in the impact of a message that is accompanied by a discounting cue. Despite a long history, the sleeper effect has been notoriously difficult to obtain or to replicate, with the exception of a pair of studies by Gruder et al. (1978). We conducted a series of 16 computer-controlled experiments and a replication of the Gruder et al. study to demonstrate that a sleeper effect can be obtained reliably when subjects (a) note the important arguments in a message, (b) receive a discounting cue after the message, and (c) rate the trustworthiness of the message communicator immediately after receiving the discounting cue. These operations are sufficiently different from those used in earlier studies to justify a new differential decay interpretation of the sleeper effect, in place of the dissociation hypothesis favored by most previous sleeper effect researchers. According to the differential decay interpretation, a sleeper effect occurs when message and discounting cue have opposite and near-equal immediate impacts that are not well-integrated in memory. The effect occurs, then, if the impact of the discounting cue decays faster than that of the message.

Physiological arousal, dissonance, and attitude change: evidence for a dissonance-arousal link and a "don't remind me" effect.

Two experiments replicated and extended research by Croyle and Cooper (1983) indicating that cognitive dissonance involves physiological arousal. In Experiment 1, subjects wrote counterattitudinal essays under conditions of high or low choice, and, to assess arousal effects owing to effort, with or without a list of arguments provided by the experimenter. In high-choice conditions only, and regardless of effort, subjects showed both arousal (heightened galvanic skin response) and attitude change. Arousal, however, did not decline following attitude change. The more effortful task (no arguments provided) produced increased arousal but not greater attitude change. In Experiment 2, the opportunity to change ones attitude following a freely chosen counterattitudinal essay was manipulated. As in Experiment 1, arousal increased following the essay but did not decline following a postessay attitude change opportunity. When subjects were not given an attitude change opportunity, however, arousal did decline. Thus, dissonance seems to create arousal, but attitude change sustains rather than reduces the arousal. It is suggested that if dissonance is a drive state, drive reduction typically may be accomplished through gradual cognitive change or forgetting.

The case for expert testimony about eyewitness memory.

Eyewitness expert testimony informs a jury about psychological processes and accuracy-related variables in eyewitness testimony. Appropriately chosen testimony is not prejudicial, and it is on sound scientific ground. Eyewitness research has established reliable, applicable findings and demonstrated that jurors have insufficient knowledge of some findings and poorly judge eyewitness accuracy. Studies of trial dynamics and reactions to eyewitnesses suggest a sizable risk of inordinate eyewitness impact, creating sizable risk of conviction on the basis of mistaken identifications. Trial simulations examining eyewitness expert testimony indicate it promotes modest, appropriate increases in skepticism about eyewitnesses, even when the expert gives a general overview of research and admits to limitations. The psychological and legal professions should develop responsible guidelines for use of expert testimony in court.

Children on the Witness Stand: A Communication/Persuasion Analysis of Jurors’ Reactions to Child Witnesses

Eyewitnesses are pivotal participants in criminal cases, and psychological research on eyewitness memory is therefore of potentially enormous practical value. Yet juries ultimately decide those cases that reach the courtroom. Research may (indeed does) yield insights about factors that influence memory and about the accuracy rates that typify a given witnessing-identification context, but an important question always remains: Do jurors take these factors into account when evaluating an eyewitness report? Put simply, how do jurors perceive and evaluate eyewitness testimony? Despite some claims to the contrary (e.g., McCloskey & Egeth, 1983), the growing research on this issue suggests that jurors’ reliance on eyewitness testimony in deciding guilt is greater than research findings merit. Jurors in laboratory studies, for example, have been found to overbelieve eyewitness identifications (Brigham & Bothwell, 1983; Lindsay, Wells, & Rumpel, 1981), rely too heavily on their impressions of eyewitness confidence (Lindsay et al., 1981; Wells, Lindsay, & Tousignant, 1980), and be misled by witness memory for trivial details when judging face-recognition accuracy (Wells & Leippe, 1981). In short, jurors’ perceptions of adult eyewitness memory and memory-relevant influences may, at least in part, be based on inaccurate stereotypes and assumptions. An important role of psychological research is to identify where and to what extent jurors’ conceptions of eyewitness memory differ from the research-derived “facts” of eyewitness memory. In turn, methods of educating jurors (e.g., through pretrial instructions) might be developed.

The Opinions and Practices of Criminal Attorneys Regarding Child Eyewitnesses: A Survey

In the past decade, increasing numbers of young children have testified in court cases requiring their ability to identify others (e.g., in cases of sexual assault by a stranger) or to remember complex events (e.g., family violence cases, child custody hearings, sexual assualt by adults known to the child). Not surprisingly, a parallel increase has occurred in efforts by psycholegal researchers to asses the accuracy of young children’s memories for faces and events. This research concerning the abilities of children to remember an event and to accurately report those memories to others has a relatively short history. Moreover, it has been conducted against a background of time-honored assumptions, by the legal system and developmental psychology, that children are unreliable witnesses—assumptions called into question by this new research.

Effects of Social-Comparative Memory Feedback on Eyewitnesses' Identification Confidence, Suggestibility, and Retrospective Memory Reports

In 2 experiments, college students watched a videotaped theft and either recounted it orally or completed an objective memory test about it. Later, some eyewitnesses received either positive or negative feedback about these memory reports, suggesting a cowitnesss report agreed or disagreed with theirs or that they had better or worse memory accuracy than most cowitnesses. Feedback influenced a number of subsequent memory-related responses. Witnesses who had received positive (vs. no) memory feedback later evinced heightened suggestibility in terms of accepting misinformation embedded in a memory interview and made identifications more confidently, quickly, and (in one condition) accurately. Witnesses who had received negative memory feedback evinced heightened suggestibility, made identifications less confidently, and recalled the witnessing and identification experience as involving poorer conditions for memory. Feedback appears to influence the overall self-credibility of memory, thereby altering confidence in both the feedback-specific memory and other aspects of memory for the event.

Asymmetry and Defense in Self-Comparison: Differential Reactions to Feedback About the Rejected and Ideal Selves

This research extended Eisenstadt and Leippes (1994) self-comparison model by examining acceptance and rejection of self-discrepant feedback and the consequences for the broader self-concept. According to the model, individuals should be more vulnerable to low-importance feedback. College students received bogus feedback about an important or unimportant, ideal or rejected trait, and rated the self-descriptiveness of that and other traits. Participants evinced greater and faster resistance to high-importance (vs. low-importance) feedback. Participants were especially susceptible to unimportant rejected feedback, but compensated by increasing the positivity of ratings on non-feedback traits. In contrast, participants resisted important rejected feedback, but evinced deflated positivity on other traits. Judgments were asymmetrical: Rejected feedback and nonfeedback traits were judged as less self-descriptive and were rated more quickly than actual or ideal traits, suggestive of defensive avoidance.

Consumer-Product and Sociopolitical Messages for Use in Studies of Persuasion

The purpose of this report is to make available two sets of persuasive messages one for fictitious brands of 12 types of consumer products and the other for 20 sociopolitical issues. These communications were developed as part of a research program directed at obtaining reliable persuasion effects.

Should We Be Partial to Partial Identification? Commentary on the Levi-Jungman Proposal

Eyewitness identification of criminal suspects from lineups and photospreads is the largest single cause of false imprisonment in the United States. Research programs have outlined experimentally proven techniques to reduce the dangers. Levi and Jungman have proposed a radical technique in which eyewitnesses choose several people from a large set of photos based on their similarity to the culprit. They argue that this will help solve many problems, including the tendency for courts to overbelieve eyewitnesses. Some problems and prospects for this new technique are discussed.