More Lies Lead to More Memory Impairments in Daily Life

The effects of deception on memory: a comparative study of actors and eyewitnesses accounts

Deception is a common occurrence in daily life and has been shown to impair memory. This study investigated the memory-undermining effects of deception in a simulated daily life scenario, focusing on the potential moderating effect of the liars' role (i.e., actor vs. eyewitness). In a 2 × 2 between-subjects design, 128 participants were randomly assigned to one of four conditions: actors who told the truth, actors who lied, eyewitnesses who told the truth, and eyewitnesses who lied. Participants engaged in a simulated shopping task, followed by an interview where they either provided truthful or deceptive responses about the items they bought (actors) or observed (eyewitnesses). Two days later, participants completed a series of memory tests assessing item memory, source memory, destination memory, and non-believed memories. Results showed that deception impaired source memory, with a greater impairment observed for actors than eyewitnesses. Deception also led to more non-believed memories and impaired item and destination memory, regardless of the liars' role. These findings suggest that the role of liars moderates the effects of deception on memory, with self-related deception (actors) leading to greater memory impairments than other-related deception (eyewitnesses).

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.