Simulation theory of empathy is a theory that holds that humans anticipate and make sense of the behavior of others by activating mental processes that, if carried into action, would produce similar behavior. This includes intentional behavior as well as the expression of emotions. The theory states that children use their own emotions to predict what others will do. Therefore, we project our own mental states onto others.
Simulation theory is not primarily a theory of empathy, but rather a theory of how people understand others—that they do so by way of a kind of empathetic response. This theory uses more biological evidence than other theories of mind, such as the theory-theory.