Simulation induces durable, extensive changes to self-knowledge

The sense of self is a hallmark of the human experience, but it is also unstable. Even simulating another person – thinking about their traits or experiences – can shift how one thinks about their own traits or experiences. Simulating a target shifts self-knowledge such that it becomes more similar to the target; in six studies, we explore how extensively these changes occur. In all studies, participants first rated themselves in a specific context, then simulated another individual in the same context, and finally considered themselves again. We calculated how participants' self-knowledge changed by comparing similarity to the target before vs. after simulation. In Studies 1–2, participants' episodic memories shifted to be more similar to the simulated target; this change persisted at least 48 h. Studies 3–4 show that semantic self-knowledge changes after considering semantically related traits, while Study 5 shows that this effect extends to cross-language traits. Together, these results suggest that simulation causes durable, extensive changes across both episodic and semantic self-knowledge.