--- - |2 Abstract From a cognitive perspective, lying can be regarded as a complex cognitive process requiring the interplay of several executive functions. Meta‐analytic research on 114 studies encompassing 3,307 participants (Suchotzki, Verschuere, Van Bockstaele, Ben‐Shakhar, & Crombez, ) suggests that computerized paradigms can reliably assess the cognitive burden of lying, with large reaction time differences between lying and truth telling. These studies, however, lack a key ingredient of real‐life deception, namely self‐initiated behavior. Research participants have typically been instructed to commit a mock crime and conceal critical information, whereas in real life, people freely choose whether or not to engage in antisocial behavior. In this study, participants (n = 433) engaged in a trivia quiz and were provided with a monetary incentive for high accuracy performance. Participants were randomly allocated to either a condition where they were instructed to cheat on the quiz (mimicking the typical laboratory set‐up) or to a condition in which they were provided with the opportunity to cheat, yet without explicit instructions to do so. Assessments of their response times in a subsequent Concealed Information Test (CIT) revealed that both instructed cheaters (n = 107) and self‐initiated cheaters (n = 142) showed the expected RT‐slowing for concealed information. The data indicate that the cognitive signature of lying is not restricted to explicitly instructed cheating, but it can also be observed for self‐initiated cheating. These findings are highly encouraging from an ecological validity perspective. - Topics in Cognitive Science, EarlyView.