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).