Personal likelihood and event familiarity influence the simulation of future events.

Episodic future thinking is the ability to project the self forward in time to preexperience a potential future event. It has been hypothesized that two components enhance simulations of future events: personal likelihood and event familiarity. Personal likelihood varies depending on the dynamics of personal goals throughout an individual's lifetime. In contrast, event familiarity varies depending on a person's accumulated schematic (also called event or semantic) knowledge about a type of event. We investigated these two components through individuals' belief in the likelihood of an event's occurrence during the next 10 years and their familiarity with a type of event. We predicted that likelihood and familiarity enhance future event simulations, making them clearer and more detailed. We used two norming studies to develop participant-specific sets of future events. In the experiment, participants simulated and described events, and they rated phenomenological aspects of their simulations. Likelihood and familiarity played individual and combined roles during future event simulation. The strongest effects were found with phenomenological ratings, with likelihood and familiarity influencing three of four measures, including interacting for other sensory details ratings. For internal details as measured using the Autobiographical Interview, likelihood influenced total details and perceptual details, and familiarity influenced total, perceptual, and time details, including their interaction for perceptual details. We conclude that event future thinking is a dynamic simulation process that uses event knowledge learned from past experience and is influenced by a person's belief of how likely an event is to occur via mental rehearsal of likely events. (PsycInfo Database Record (c) 2025 APA, all rights reserved).