The simulation theory of empathy holds that humans anticipate and make sense of the behavior of others by activating mental processes that, if they culminated in action, would produce similar behavior. This includes intentional behavior as well as the expression of emotions. The theory says that children use their own emotions to predict what others will do; we project our own mental states onto others. Simulation theory is not primarily a theory about 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. Simulation theory is based in philosophy of mind, a branch of philosophy that studies the nature of the mind and its relationship to the brain, especially the work of Alvin Goldman and Robert Gordon. The discovery of mirror neurons in macaque monkeys provides a physiological mechanism to explain the common coding between perception and action (see Wolfgang Prinz) and the hypothesis of a similar mirror neuron system in the human brain. Since the discovery of the mirror neuron system, many studies have been carried out to examine the role of this system in action understanding, emotion, and other social functions. Mirror neurons are activated both when actions are executed and when actions are observed. This function of mirror neurons may explain how people recognize and understand the states of others: they mirror the observed action in the brain as if they conducted the observed action. Two sets of evidence suggest that mirror neurons in the monkey have a role in action understanding. First, the activation of mirror neurons requires biological effectors such as the hand or mouth. Mirror neurons do not respond to actions undertaken by tools like pliers. Mirror neurons respond to neither the sight of an object alone nor to an action without an object (intransitive action). Umilta and colleagues demonstrated that a subset of mirror neurons fired in the observer when a final critical part of the action was not visible to that observer.
Roland John Tormey, Nihat Kotluk