اثر کمرویی بر روی حافظه شاهدان عینی و استعداد ابتلا به اطلاعات نادرست

Witness shyness was investigated to determine its effect on eyewitness recall memory and susceptibility to the ‘misinformation effect’. Thirty-nine shy and 41 non-shy participants were exposed to a filmed mock crime. Recall accuracy was assessed via free recall and directed recall. Participants were subsequently asked to read a script containing misinformation. The direct recall questionnaire then was re-administered to assess witnesses’ susceptibility to the ‘misinformation effect’. Shy and non-shy witnesses produced comparable recall accuracy rates. Person details were recalled more accurately prior to misinformation by both groups. After the misinformation was introduced, both groups produced significantly higher recall accuracy rates for event details.

Shyness may have important consequences for eyewitness memory when one considers the neurological, neuroendocrinal, and physiological differences between shy and non-shy individuals (Crozier, 2001). Considering Hosch’s (1994) theory that personality traits with biological substrates are most likely to contribute to individual differences in eyewitness performance, shyness is a good candidate to consider. The present study examined witness shyness and its facilitating and debilitating effects on eyewitness memory and susceptibility to misinformation among adult witnesses. 1.1. Shyness Buss (1986) defined shyness as anxious self-preoccupation and behavioral inhibition in social contexts due to the prospect of being negatively evaluated by others. Of particular interest is the consistent finding across studies that behavioral inhibition is associated with higher levels of physiological reactivity including increased heart rate and an elevated production of the stress hormone cortisol (Kagan, Reznick, & Snidman, 1987). Zimmerman and Stansbury (2004) argue that under critical circumstances, an elevation in cortisol levels is adaptive because it allows the body to respond to the perceived challenging situation by mobilizing the organism’s energy resources in order to effectively manage the stressful situation. In an eyewitness context, this heightened arousal could prove to be beneficial given that it may compel shy witnesses to devote their energy to assess and evaluate the perceived threat (i.e., crime/perpetrator) that may then facilitate eyewitness memory. The only available research that has tested this shyness hypothesis among adult witnesses is that of Pozzulo, Coplan, and Wilson (2005) with two experiments. In the first experiment, shy and non-shy participants watched a videotaped mock crime. Participants were then asked to recall perpetrator and crime environment details. Shy and non-shy witnesses did not differ significantly in terms of perpetrator details; however, shy witnesses recalled fewer crime details. Following Van Ameringen, Mancini, and Oakman’s (1998) supposition that shy individuals are particularly sensitive to and threatened by novel persons entering their environment, Pozzulo and colleagues speculated that shy witnesses might have been so concerned about the “person” that they were unable to encode many environmental items. In the second experiment, arousal was manipulated to determine if it would interact with shyness to influence eyewitness memory. With induced arousal, non-shy witnesses were more accurate describing the perpetrator than shy witnesses. Shy witnesses may have experienced such an increase in arousal to render them less able to encode and accurately recall perpetrator details whereas for non-shy witnesses, the increase in arousal facilitated their recall. Although this study illustrated the facilitating effects of shyness on eyewitness performance under some conditions (i.e., under low arousal conditions), it also illustrated some debilitating effects (i.e., under increased arousal). The Yerkes–Dodson rule ( Yerkes & Dodson, 1908) dictates that performance increases with arousal but only to a certain point (i.e., when levels of arousal are too high, performance will decrease). Shy witnesses may already be at their ‘optimal’ level of arousal for eyewitness performance when performing at baseline and the introduction of externally induced arousal may have pushed shy witnesses beyond their optimal level. On the other hand, for non-shy witnesses, the additional external arousal may serve to enhance their performance, and make them more accurate witnesses. Shy individuals also have been found to have a fear of negative evaluation (Clark & Arkowitz, 1975) that, in turn, may influence task performance (e.g., eyewitness recall). For instance, considering the strong correlation between anxiety and shyness (Cheek & Buss, 1981), high-anxious (HA) individuals have been found to worry when under “evaluative threat” (e.g., Morris and Liebert, 1973 and Wine, 1982). Sarason (1972) argued that when HA individuals are asked to perform a specific task, they are effectively in a dual-task situation because their attention is divided between the actual task and the processing of task-irrelevant thoughts (i.e., thoughts concerning negative evaluations or the disapproval of others). This anticipation of negative feedback is an important factor to consider in explaining the performance of shy witnesses. It is possible that shy witnesses may be preoccupied with thoughts of negative evaluations from the experimenter (or, law enforcement authorities in a real-life situation), and thus may perform more poorly at providing accurate descriptions of the perpetrator and crime event. Shy individuals also tend to lack confidence (Crozier, 1982) and express larger perceived skill deficits compared to non-shy individuals (Jackson, Towson, & Narduzzi, 1997). Crozier (1979) further argued that shy individuals may assume that they are inept even before entering a social situation (e.g., eyewitness event as a social situation; Wells & Luus, 1990). Some adverse consequences of these could be a willingness to please others (e.g., the experimenter) and a higher susceptibility to external factors (e.g., misinformation). 1.2. The misinformation effect The misinformation effect, or post-event information effect, is a phenomenon whereby the presentation of inaccurate information (misinformation) to witnesses after an event has occurred alters their recollections of the original event in a subsequent recall task (Loftus, 1975). To date, numerous debates exist on how and why this phenomenon occurs (Loftus et al., 1978 and McCloskey and Zaragoza, 1985). One explanation that is of relevance to the present study is the misinformation acceptance hypothesis, which maintains that some participants choose to report the misinformation because of a perceived social demand (i.e., the participants choose the answer they think the experimenter wants, resulting in the misinformation effect; McCloskey & Zaragoza, 1985). Given that shy witnesses may be prone to experimenter pleasing in order to avoid negative evaluations, they may be more susceptible to the misinformation effect. Several studies have explored individual factors such as introversion–extraversion and shyness, and their links to suggestibility and false memory creation in adults. Although shyness and introversion are two separate traits, they are highly correlated (Crozier, 1982). For instance, shy individuals have been found to be significantly more introverted than non-shy individuals (Heiser, Turner, & Beidel, 2003) and other studies have demonstrated that shyness and extraversion are negatively correlated (e.g., Ziller & Rorer, 1985). Janowsky, Morter, and Tancer (2000) suggest that introversion manifests itself early in life as shyness. Thus, studies on introversion may provide insight as to how shy individuals may react when presented with misinformation, especially given that most studies explore the relationship between eyewitness memory and introversion and less research is available on eyewitness memory and shyness. A study by Ward and Loftus (1985) demonstrated that introverts are indeed more susceptible to the misinformation effect. Gudjonsson, Sigurdsson, Bragason, Einarsson, and Valdimorsdottir (2004) also demonstrated that the reserved nature of the introvert and their lack of assertiveness made them more inclined to exhibit compliant behavior when pressured by others. Gudjonsson and colleagues describe compliance as the tendency of an individual to conform to propositions, instructions, or requests for some immediate gain. Taken together, these results suggest that shy witnesses may be more susceptible to the misinformation effect. 1.3. Present study The present study explored the influence of shyness on eyewitness recall memory (crime and perpetrator details) and susceptibility to the misinformation effect. It was predicted that shy witnesses would be less accurate in reporting event details than person details than non-shy witnesses during free recall and directed recall (prior to the misinformation). It was predicted that, following the misinformation, shy witnesses would be less accurate and more likely to report misinformation than non-shy witnesses.