The role of working memory capacity and cognitive load in producing and detecting deception

Abstract

The purpose of this study was to examine the effects of age, working memory capacity (WMC) and cognitive load on people's ability to tell and detect lies. The literature is inconsistent on what individual characteristics are critical to being a good liar. Zukerman, DePaulo, and Rosenthal (1981) suggested that lying is cognitively demanding. Therefore, WMC might provide an advantage for some when telling a convincing lie, such that higher WMC individuals can handle the high cognitive load associated with lying. I examined this across two experiments. I predicted that individuals with higher WMC would be able to better tell more convincing lies, because such individuals are better at suppressing prepotent, but goal irrelevant information, such as the truth. Additionally, higher WMC individuals are better equipped to focus and tune out distraction that accompanies a high cognitive load. I also predicted that younger individuals will have an easier time telling convincing lies than older adults. As we age, cognitive functioning, like WMC, declines, and with this decline, so does our ability to deceive others. In Experiment 1, young adult dyads took turns telling truths and lies, under high and low cognitive load. The detector tried to determine whether their partner was truthful or deceitful. In Experiment 2, younger and older adults told truths and lies into a camera and two young adult detectors tried to detect the truths and lies, at a later time. I found a positive relationship between WMC and telling lies such that higher WMC individuals had fewer of their lies detected when under high load. I also found that a higher WMC improved the ability to comply when asked to tell a truth or lie. I also found that when responding to questions, participants found it easier to comply when asked to lie or when under high cognitive load. In regard to age differences, older adults found it more difficult to tell lies than truths. Issues within deception could involve specific memory processes and require more research to understand what aspects of memory are involved in telling a convincing lie.