Suggestibility occurs when inaccurate information is incorporated into currently existing memories. The present study examined the effect of forewarning on suggestibility, including the influence of working memory capacity (WMC). The main hypotheses are that forewarnings will reduce suggestibility compared to the control group and that high-WMC will yield lower suggestibility compared to medium- and low-WMC. The final hypothesis is that WMC and forewarning will interact such that low-WMC individuals will benefit more than high-WMC individuals from the forewarning. A sample of 123 college students was recruited. Participants watched a clip of the TV-show 24. WMC was then assessed followed by the presentation of a misleading narrative. Prior to listening to the narrative, they read a set of instructions that sometimes contained the forewarning. After listening to the misleading narrative, participants took a test over their memories of the film. A 2 X 3 ANOVA was conducted and found a main effect for forewarning. No other effect was significant. The current results only support the first main hypothesis that forewarning reduces suggestibility. These results could be used to help prepare eyewitnesses to resist misinformation in the period between witnessing an event and reporting the event during a later trial.

Pulling from past research on cross-race identifications, the purpose of this study is to investigate the effects of both mixed race participants and perpetrators on eyewitness accuracy and confidence levels. In the study, participants will be shown a randomly assigned photograph of an individual from one of three racial categories: Asian, Mixed (some part Asian), and non-Asian. They will then be asked to read a fictional convenience store robbery vignette and identify the perpetrator from a 9 person simultaneous photo lineup, rate their confidence, and answer a series of questions regarding the diversity of their neighborhood, past or present school or workplace, and friend group. There are no predicted main effects. However, there are three expected interactions: the first between participant race and perpetrator race, such that the perpetrator race will not influence the accuracy for Asian and non-Asian participants. The second proposed interaction is between exposure and race, such that high exposure will cause race to be irrelevant with regard to identification accuracy. The third expected interaction is between participant race and perpetrator race, such that perpetrator race will not influence the confidence levels for mixed race participants, but will influence the accuracy for Asian and non-Asian participants.

The chief aim of this dissertation was to establish the respective contributions of automatic and intentional memory processes to misinformation effects in 5-, 8-, and 9-year-old children. In the first two experiments children were presented with a picture story followed by misleading post-event details that were either read to participants, or were self-generated in response to semantic and perceptual hints. Children were then presented with original and suggested items and given a yes / no recognition test under inclusion or exclusion instructions. The application of Jacoby’s (1991) process dissociation procedure to children’s recognition performance revealed that the contribution of intentional processing to misinformation acceptance increased following the self-generation of suggestions. Automatic processing made a strong contribution to misinformation effects regardless of the way that misinformation was encoded. Experiment 3 extended this general pattern of results to a forced choice recognition paradigm. Experiment 4 examined the role of social demand factors in children’s suggestibility using Belli’s (1989) yes / no retrieval paradigm. Little evidence of an influence of social demand on children’s suggestible responses was found with automatic processes again the predominant factor determining suggestibility. In the final experiment, the temporal order of the original and post-event phases was reversed such that 5-year-olds were initially presented with a post-event summary containing misinformation, followed by a witnessed event. The results of this study confirmed that children’s suggestions were unlikely to be the result of trace alteration or social demand. The implications of the findings for theoretical accounts of the misinformation effect in children’s recognition and for children’s eyewitness testimony are discussed. / PhD Doctorate

How can empirical science, and psychology in particular, be harnessed to avoid or eliminate unwanted biases? The body of work herein explores this question across twelve experiments. The first approach we consider is placing the onus on the individual to root out any already existing bias within him or herself. Chapter 3, for example, presents experiments that assess whether people (viz., jurors during voir dire) can accurately "self-diagnose" when they are irreparably biased by negative pretrial publicity. (The answer is a resounding no). A second approach is to try and avoid letting bias enter the courtroom in the first place. Chapter 4, for example, provides an experimental test of an institutional solution known as blind expertise, wherein certain biases of an expert witness are avoided by having an intermediary pick the expert, and then having the expert render an opinion before knowing which litigant made the request. In Chapter 7, we consider a third approach to handling bias, one that concedes it will exist in the courtroom. Namely, instruct jurors on the existence of bias, so that they can try to weigh it properly. To this end we test a recently enacted New Jersey instruction on eyewitness testimony. We find that jurors do not become more sensitive to low versus high evidence quality, but instead they discount the eyewitness testimony across the board. Across this inquiry, we deploy several novel tactics; in Chapter 5, for instance, we explore how continuous response measurement (CRM) can provide unique insights into the study of reasoning, and in particular how jurors parse trial evidence. We end in chapter 8 with a more general discussion of how behavioral science can be applied across law and policy.

Research supports the notion that weapons impair eyewitnesses' memory for visual information (weapon focus effect). Pickel and Betts (1999) found that the presence of a weapon can also interfere with witnesses' memory for auditory information. The primary objective of the current study was to replicate Pickel and Betts's (1999) findings, to extend their findings by implementing different methodological procedures, and to control for a confound associated with their study. A secondary goal was to further investigate the impact that arousal and novelty have on the weapon focus effect. Participants watched a videotape depicting a story about a man stalking a woman. The man approached the woman holding either a switchblade knife or a black ballpoint pen. The man's conversation varied so that it was either easy or difficult to comprehend. Participants then completed questionnaires assessing their arousal level, memory for visual and auditory information, and perceived unusualness of the object carried by the target. [n addition, they attempted to identify the target in a photo and audio lineup. Results indicate that the presence of a weapon does not affect memory for vocal characteristics or for semantic content of speech when the content of the message is rather simple. As the complexity of the message increases, however, a weapon will interfere with witnesses' memory for the content. Also, results support the hypothesis that the weapon focus effect occurs because the weapon is perceived to be unusual and that increased levels of arousal are not necessary to obtain the effect. Analyses revealed no significant effects or interactions related to witnesses' ability to identify the man in the photo or audio lineup. The results supported Pickel and Betts's (1999) conclusions, thus increasing our knowledge concerning the reliability of eyewitness testimony. / Department of Psychological Science

Based on the multiple resource model, a more difficult auditory task should use more attentional resources and leave fewer resources to attend to visual information. Research suggests that trying to listen to and understand a speaker with an accent is difficult. In addition, stimuli that are considered threatening can raise stress levels and reduce the amount of attentional resources available. In the present study, participants watched one of four videos that portrayed a bank robber delivering a statement with either a Midwestern or Serbian accent and with either high or low level of threat. For the perpetrator’s appearance, participants provided significantly more correct and fewer incorrect details if they heard the Midwestern accent or the low threat statement. These results support the multiple resource model and suggest that further research is needed with the model in eyewitness memory. / Department of Psychological Science

Previous research on the weapon focus effect indicates that schematic knowledge plays a large role in adult witnesses' ability to recall details of a crime. This study investigated whether the weapon focus effect would be found in young children (4- and 5- year-olds), whose schemas are less developed than those of adults. An experiment was conducted in which adults and children viewed a videotape depicting a male target stealing money from a woman's purse. In the four conditions, the target's apparent occupation and the objects that he held were manipulated, so that only one condition depicted a schema inconsistency between his occupation and the object. After watching the videotape, the participants were interviewed for details regarding the target's physical appearance and the object. As predicted, the schema inconsistency resulted in decreased recall accuracy for both children and adults. These results suggest that the weapon focus effect can be generalized to young children and that their eyewitness accounts are similar to those of adults. Additionally, adults recalled a significantly greater number of details than did the children, which was also predicted. It was interesting and unexpected to find that overall. adults recalled significantly more accurate descriptions than the children. This finding was contradictory to the results of some previous studies on eyewitness memory. / Department of Psychological Science

The effect of a weapon on memory accuracy for children and adults was examined. One-hundred eighty-six participants (87 7- and 8-year-old children and 99 college undergraduates) viewed one of four videotaped scenes in which a target individual committed a crime while carrying either a weapon that was consistent or inconsistent with his schema role or a neutral non-weapon that was consistent with his role. Participants were individually interviewed about the target's physical appearance. The results indicated that participants of both age groups were less accurate when the target individual carried a weapon that was inconsistent rather than consistent with his schema role. The results also indicated that adults were more accurate overall than children. These findings are consistent with previous findings on weapon focus effect and add to our knowledge of the development of memory. / Department of Psychological Science

This research examined the impact of eyewitness identification decisions on student-investigators. Undergraduates played the role of police investigators and interviewed student-witnesses who in Studies 1 and 2 had been shown either a good or poor view of the perpetrator or in Study 3 viewed either a Caucasian or an Asian criminal, in a video-taped crime. Based on information obtained from the witness, student-investigators then chose a suspect from a database containing information about potential suspects and rated the probability that their suspect was the culprit. Investigators then administered a photo lineup to witnesses, and re-rated the probability that their suspect was guilty. Student-investigators were highly influenced by eyewitness identification decisions, typically overestimating the information gained from the identification decision (except under conditions that led witnesses to be very accurate), and generally did not differentiate between accurate and inaccurate witnesses.

Eyewitness identification evidence is often essential in criminal investigations, yet little is known about how police investigators evaluate identification evidence. This research simulated a police investigation by having participant-investigators obtain information about a crime, examine a database of potential suspects with the goal of choosing a likely suspect for the crime, and evaluate an eyewitness's lineup identification decision. Experiments 1 and 2 examined the effect of order of presentation of the eyewitness decision. When the eyewitness identified the investigator's suspect, ratings of the suspect's guilt were similar regardless of when the eyewitness decision occurred. However, when the witness reported that the culprit was not present in the lineup, a recency effect occurred (the information that was presented last had a larger impact). Experiment 3 continued to examine order effects while also examining how investigators evaluated alibi information and eyewitness testimony when they had already identified a suspect in the case. The investigators evaluated alibi evidence that was either strong or weak (in regards to exonerating the suspect) and eyewitness evidence involving a witness who either identified the investigator's suspect or rejected the suspect (by not making an identification). The order of presentation of the alibi information and eyewitness testimony was manipulated such that half of the participants received the alibi information before the eyewitness testimony while the other half received the alibi information after the eyewitness testimony. Both the eyewitness decision and alibi evidence affected ratings of guilt. A recency effect was present only in the ID Suspect/Strong alibi conditions, such that when investigators saw the witness identify the suspect and then received the strong alibi, they rated the likelihood that their suspect had committed the crime as lower than when they received the strong alibi first and then saw the witness identification. Otherwise, the two forms of evidence had an additive effect. Together, these studies provide a valuable examination of the influence of presentation order and the importance of different forms of evidence on role-playing police investigators.