ABSTRACT

Most of the research on deception suggests that lying is significantly more costly from a cognitive point of view than truth-telling. This was documented by increased reaction times and decreased accuracy of deceptive responses. Recent evidence, however, indicates that the “dominance” of the truth response is malleable and that it can be altered through practice, in which case the deceptive response can become prepotent, thus less cognitively demanding. Our objective was to assess how initial deceptive responses affect subsequent truth telling and vice-versa in the Reaction Time-based Concealed Information Test (RT-based CIT). In order to reach our objective we administered the RT-based CIT to two experimental groups, one in which subjects were instructed to tell the truth about recognizing items from a mock crime in a first block, and then to deny it in a second block, and another group in which subjects first lied, and then told the truth. Results indicated that deceptive responses took longer and were less accurate in the Truth first group than in the Lie first group, suggesting that repeated practice with the truth negatively impacts subsequent deceptive responses. Interestingly, the opposite effect was also noted, meaning that subsequent honest responses were less accurate in subjects who practiced deception in the initial block. This suggests that performance on the RT-based CIT can be manipulated through previous exposure to tasks that require repeated truth telling or lying about crime-related items.

KEYWORDS: memory detection, Reaction-time based Concealed Information Test, cognitive cost, practice effects, truth-telling, deception

PAGES: 283-297