Meta-analyses reveal that behavioral differences between liars and truth tellers are small. To facilitate lie detection, researchers are currently developing interviewing approaches to increase these differences. Some of these approaches assume that lying is cognitively more difficult than truth telling; however, they are not based on specific cognitive theories of lie production, which are rare. Here we examined one existing theory, Walczyk et al.'s (2014) Activation-Decision-Construction-Action Theory (ADCAT). We tested the Decision component. According to ADCAT, people decide whether to lie or tell the truth as if they were using a specific mathematical formula to calculate the motivation to lie from (a) the probability of a number of outcomes derived from lying vs. telling the truth, and (b) the costs/benefits associated with each outcome. In this study, participants read several hypothetical scenarios and indicated whether they would lie or tell the truth in each scenario (Questionnaire 1). Next, they answered several questions about the consequences of lying vs. telling the truth in each scenario, and rated the probability and valence of each consequence (Questionnaire 2). Significant associations were found between the participants' dichotomous decision to lie/tell the truth in Questionnaire 1 and their motivation to lie scores calculated from the Questionnaire 2 data. However, interestingly, whereas the expected consequences of truth telling were associated with the decision to lie vs. tell the truth, the expected consequences of lying were not. Suggestions are made to refine ADCAT, which can be a useful theoretical framework to guide deception research.