Mental contrasting prevents a negative future by changing the explicit and implicit meaning of reality

People often anticipate feared, negative future events but still fail to take preventive action-simply imagining feared outcomes does not reliably prompt behavior change. Research has shown that mental contrasting-imagining a negative future and then reflecting on a positive reality in the present-can translate this fear into action. However, the psychological mechanisms underlying this effect remain unexplored. Across five experiments (two cross-sectional and three longitudinal with 1-month follow-ups), we examined how mental contrasting of a negative future promotes preventive behavior by altering interpretations of current reality. Supporting our hypothesis, participants who engaged in mental contrasting evaluated their reality as more precious than those engaged in reverse contrasting (Studies 1 and 3) and those in the valence control condition (Study 2). These shifts in evaluations of reality predicted greater preventive behavior over the following month (Studies 1 and 3). In addition, mental contrasting changed implicit evaluations of reality in the same direction, as measured by the extrinsic affective Simon task (Studies 4 and 5). These implicit changes further predicted preventive action 1 month later (Study 5). Our research identifies a key mechanism by which mental contrasting converts fear into action: It changes how people explicitly and implicitly evaluate the meaning of their current reality. (PsycInfo Database Record (c) 2026 APA, all rights reserved).