Cognitive load promotes honesty

In three experiments, we examined the cognitive underpinnings of self-serving dishonesty by manipulating cognitive load under different incentive structures. Participants could increase a financial bonus by misreporting outcomes of private die rolls without any risk of detection. At the same time, they had to remember letter strings of varying length. If honesty is the automatic response tendency and dishonesty is cognitively demanding, lying behavior should be less evident under high cognitive load. This hypothesis was supported by the outcome of two out of three experiments. We further manipulated whether all trials or only one random trial determined payoff to modulate reward adaptation over time (Experiment 2) and whether payoff was framed as a financial gain or loss (Experiment 3). The payoff scheme of one random or all trials did not affect lying behavior and, discordant to earlier research, facing losses instead of gains did not increase lying behavior. Finally, cognitive load and incentive frame interacted significantly, but contrary to our assumption gains increased lying under low cognitive load. While the impact of cognitive load on dishonesty appears to be comparably robust, motivational influences seem to be more elusive than commonly assumed in current theorizing.