The impact of false denials on forgetting and false memory

Discernment of Children's True and False Memory Reports: Police Officers and Laypersons

Adults' ability to accurately evaluate children's statements can have far-reaching consequences within the legal system. This study examined the evaluations of police officers ("experts") and laypersons ("nonexperts") when presented with videotaped interviews of children aged 3 and 5 years who provided either true or false reports or denials. Participants were drawn from several counties in the eastern United States. Children's interview statements fell within four statement types: accurate reports, false reports, accurate denials, and false denials. Both groups of participants displayed overbelief in false denials. Several control variables predicted accuracy, including children's age and children's race. A significant interaction emerged: Experts (vs. nonexperts) had greater odds of being accurate when judging false reports (vs. false denials). These findings highlight the challenges adults face when distinguishing between various types of children's statements. The results have important implications for legal contexts, emphasizing that fact finders need to be mindful of the risks associated with both overaccepting false denials and accepting false reports.

The effect of lying on memory in daily life: Does motivation matter?

Recently, there has been renewed interest in the effect of lying on memory. A growing body of studies has documented that lying can impair memories and cause memory disruptions, such as forgetting and false memories, to a greater degree than telling the truth. This study aimed to investigate whether motivation plays a role in the effect of lying on memory. The present study utilized a daily life paradigm and manipulated three conditions: truth telling, internally motivated lying, and externally motivated lying. We asked participants to engage in a shopping task and to tell lies (externally motivated lying group) or to choose between telling the truth (truth-telling group) and telling lies (internally motivated lying group) in the interview. Forty-eight hours later, the participants were instructed to truthfully carry out multiple memory assessments. The principal findings of this research are that lying can result in memory impairments, and internally motivated lying can lead to greater impairment in source memory than externally motivated lying. Moreover, no significant differences between the two lying groups were found in the memory tests. The empirical findings of this study provide new insights into the effect of lying on memory.

External and internal influences yield similar memory effects: the role of deception and suggestion

In legal cases, testimonies can become contaminated because of an amalgam of external and internal influences on memory. It is well-established that external influences (e.g., suggestive interviews) can hurt memory. However, less focus has been placed on the impact of internal influences (e.g., lying) on memory. In the current review, we show that the available evidence suggests that both external and internal influences exert similar effects on memory. That is, we review studies showing that suggesting non-occurrences and suggesting non-experiences can lead to omission errors and false memories, respectively. Likewise, these memory effects are also observed when focusing on internal influences. That is, false denials, feigning amnesia and fabrication have been shown to affect memory in terms of forgetting (i.e., omissions) and false memories (i.e., commissions). Also, we show that both external and internal influences can lead to changes in the belief that an event occurred. We argue that in legal cases, triers of fact should concentrate on whether both types of influences might have affected testimonial accuracy in witnesses, victims, and suspects.

Can false denials turn fact into fiction? The effect of false denials on memory for self-performed actions

We examined the mnemonic effects of falsely denying a self-performed action. Specifically, participants (N = 30) performed, imagined, or received no instruction about 24 action statements (e.g., "cross your arms"). Next, their memory for whether they had performed, imagined, or did nothing (i.e., received no instructions) with these actions was tested. Subsequently, participants were instructed to repeatedly deny an action they had performed (false denial) and to repeatedly claim to have performed an action they had only imagined (false admission). In a final sorting memory task, 54% (n = 16) of participants erroneously indicated, after false admissions, that they had performed the imagined action. None of the participants indicated that they had only imagined an action after false denials, showing that it might be difficult to forget a performed action, even after repeatedly denying it. The current experiment sets the stage for future research to investigate why it seems to be difficult to forget performed actions.

Simulating denial increases false memory rates for abuse unrelated information

Victims of abuse might deny their traumatic experiences. We studied mnemonic effects of simulating false denial of a child sexual abuse narrative. Participants (N = 127) read and empathized with the main character of this narrative. Next, half were instructed to falsely deny abuse-related information while others responded honestly in an interview. One week later, participants received misinformation for the narrative and interview. In a final source memory task, participants' memory for the narrative and interview was tested. Participants who falsely denied abuse-related information endorsed more abuse-unrelated misinformation about the event than honest participants. Abuse-related false memory rates did not statistically differ between the groups, and false denials were not related to omission errors about (1) the interview and (2) narrative. Hence, victim's memory for abuse-related information related to their experience might not be affected by a false denial, and inconsistencies surrounding the abuse-unrelated information are more likely to take place.

Research on the Effects of Lying on Memory: A Scientometric Analysis and a Call for New Studies

Research on the effects of lying and memory is increasingly attracting empirical attention. In the current manuscript, a scientometric analysis was carried out on the mnemonic consequences of lying. This analysis took into account 70 published articles extracted from Scopus and Web of Science databases from 1998 to 2021. A scientometric analysis was conducted in order to visualize the state of the art on this line of research (i.e., authors, countries, institutions, journals, and co-citations). Additionally, a keywords’ cluster analysis was executed to investigate the main keywords used in the published papers. Based on the keywords’ cluster analysis, we identified the main aims and critical issues of the reviewed papers. The United States and the Netherlands are the two most productive countries into the effects of lying on memory. The top five authors are mainly from European countries and wrote from 6 to 15 articles. The cluster analysis detected three clusters of keywords. The critical issues of this line of research are mainly related to the generalizability of the achieved findings for real situations, a lack of a direct control of the manipulation adopted, and a need of additional measures. The current analysis provides a comprehensive overview and understanding of existing research on the effects of lying on memory and provides possible future directions of this research domain.

More Lies Lead to More Memory Impairments in Daily Life

Previous studies have demonstrated that lying can undermine memory and that its memory-undermining effects could be modulated by the cognitive resources required to tell lies. We extended the investigation of the memory-undermining effect by using a daily life setting in which participants were highly involved in a mock shopping task. Participants were randomly assigned to truth-telling, denying or mixed lying conditions. After finishing the shopping task, participants were told that two people wanted to know about their shopping lists and would ask them some questions in an interview. During the interview, participants were asked whether each of ten items were on the shopping list, five of which were randomly selected from the shopping list, while the other five were not sold in the store. In answering the interview questions, the truth-telling group was asked to respond honestly, the denying group was asked to give denial responses, and the mixed lying group was asked to respond deceptively. Thus, the denying group told five lies and the mixed lying group told ten lies in the interview. The item memory test, source memory test and destination memory test were given in an orderly manner 48 h after the interview. We found that the mixed lying group, rather than the denying group, forgot the lies they told in the interview and mistakenly believed they had lied about something that they had not lied about. Moreover, the mixed lying group retained fewer memories about the person they responded to than the honest group. In addition, participants in the mixed lying group had more non-believed memories than those in the truth-telling group in both item and source memory tests. We conclude that more lies could result in more memory disruptions in daily life.

Who did I lie to that day? Deception impairs memory in daily life

Research has demonstrated that deceptive responses can undermine item and source memories. However, previous studies have often randomly assigned participants to an honest or deception group and asked them to respond in specific ways in an interview, rather than providing them a choice of what response to give. Moreover, little attention has been given to destination memory in previous research. Using a daily life paradigm, we investigated the effects of deception on memory. After completing a mock shopping task, participants were told that someone would ask them questions about their shopping lists. The participants voluntarily chose to tell the truth or lie in the interview and were encouraged to respond as they would in their daily lives. An item memory test, source memory test and destination memory test were given 48 h after the interview. Source and destination memories but not item memories were impaired for participants who chose to lie. Specifically, liars forgot the things about which they lied and mistakenly believed that they lied about many things that they did not, and they also did not remember to whom they lied. We conclude that deception can disrupt memory in daily life.

Involvement Modulates the Effects of Deception on Memory in Daily Life

Previous studies have demonstrated that liars who adopt a false denial strategy often forget what they lied about, which has been labeled the denial-induced forgetting (DIF) effect. However, several investigations have not found such an effect. It has been suggested that involvement might play a role in the inconsistency. The present study was designed to directly determine whether involvement modulates the effects of deception on memory. Participants were assigned randomly to either high- or low-involvement conditions and were required to complete a mock shopping task. They were then asked to participate in an interview in which they were asked to respond honestly or deceptively. Two days later, final memory tests were given, and the participants were asked to give honest responses. We found a DIF effect in the high-involvement condition but not in the low-involvement condition. Moreover, the liars in the high-involvement condition created more non-believed memories in the source memory test and the destination memory test than the honest participants. In addition, liars in both the high- and low-involvement conditions forgot who they lied to. We conclude that the effects of deception on memory could be influenced by the degree of involvement.

The role of executive functions in the effects of lying on memory

Recent studies have demonstrated that lying can affect memory and that such memory effects are based on the cognitive load required in performing the lie. The present study aimed to verify whether the impact of two deceptive strategies (i.e., false denials and fabrication) depends on individuals' cognitive resources in terms of Executive Functions (i.e., EF: Shifting, Inhibition, and Updating). A sample of 147 participants watched a video of a robbery and then were instructed to either fabricate (i.e., fabrication condition), deny (i.e. false denial condition), or tell the truth (i.e., truth-telling condition) to some questions about the crime. Two days later, all participants had to provide an honest account on a final memory test where they indicated their memory for having discussed details (i.e., fabricated, denied, or told the truth) and their memory for the video. Finally, their EF resources were also assessed. Our findings demonstrated that individual differences in EFs played a role in how the event was recalled and on the effects of lying on memory. That is, memory for the event after having lied depended especially on individuals' Shifting resources. We also found that the two deceptive strategies differentially affected individuals' memory for the interview and for the event: Denying affected memory for the interview while fabricating affected memory for the event. Our findings can inform legal professionals on the possibility to assess individuals' EF as an indicator of witnesses' credibility.

Can suggestions of non-occurrence lead to claims that witnessed events did not happen?

In three experiments, we examined whether general suggestions of non-occurrence -suggestions that experienced events did not occur- would lead participants to claim that events they witnessed never happened. Participants viewed a video depicting the investigation of a child kidnapping case and subsequently were exposed to suggestions of non-occurrence either once (Experiments 1 and 3) or three times (Experiments 2 and 3). The results provided no evidence that single suggestions of non-occurrence influenced participants' memories or belief (Experiments 1 and 3). However, in two experiments (E2 and E3) the results provided clear evidence that repeated elaboration of suggestions of non-occurrence led participants to claim that the events they witnessed never happened. The finding that participants were influenced by repeated, but not single elaboration of suggestions of non-occurrence shows that reflective elaboration processes played an important role in leading participants to disbelieve the events they had witnessed.