Reading other people’s mind by simulation

There is increasing neuropsychological evidence that, in order to interpret and predict other people`s motor activities, people emulate them covertly. Psychologically, this emulation comes as imitation, and it appears that imitation plays a significant role in our ability to understand other peoples` actions, based on an understanding of the mental life (goals, intentions, etc.) driving those actions. Motor behavior can be emulated because other people`s bodies can be mapped onto our own bodies; similarly mental processes can be simulated because other people`s structure of mind can be mapped onto our own minds. This general idea is applied to the understanding of other people`s minds and to the understanding of one`s own mind in different situations (i.e, to hypothetical decisions). Empirically, we investigate the role of simulation in five different areas using a variety of procedures. (i) In the perceptual realm we predict that nonconceptual perceptions (e.g., of different hues of a color that we can differentiate perceptually while failing to be able to label them differently) can only be arrived at by simulation. (ii) In the area of the perceived duration of an activity (e.g. why does an interesting activity appear short, and a dull activity appear long?) we propose that the influence of duration on thought processes cannot be simulated. (iii) In the area of the influence of feelings on cognitive processes we expect that empathy (a sort of emotional simulation) depends on the imitation of relevant bodily expressions of the people to be understood. (iv) For metacognitions we predict that judgments of learning are based on simulation, while judgments of forgetting cannot be based on simulation (e.g., how could you have a metacognitive feeling about a forgotten item?). Finally (v) we plan to further develop knowledge about the neurocognitive basis of simulation by using modern brain imaging techniques in conjunction with behavioral data. All this aims at identifying the limits of simulation. Knowledge of these limits leads to a better understanding of other people`s thoughts, and to a better prediction of one`s own future behavior.

Various strategies exist for reading other peoples thoughts and of predicting their behavior. One groups of strategies uses knowledge: knowledge about some specific person, some specific group of people, or people in general. The view that people use knowledge in predicting thoughts and behavior of other people is called theory-theory. Another group makes use of privileged access to ones own preferences, by exploiting the similarity between oneself and other people: one imagines being the other person and predict ones own reactions for the other person. This strategy is called simulation. Mental simulation is possible if the other person is not physically present, but has to be imagined hypothetically. The project Reading other peoples mind by simulation has shown that (1) simulation is a common strategy for predicting other peoples thoughts, feelings, and behavior; (2) prediction by simulation is in most cases successful, and (3) people use a mix of simulation and theory concurrently in most situations. This mix depends on the situation at hand: simulation is more prevalent when predicting unknown people as compared to well-known people.A related topic to the prediction of the thoughts and feelings of other people is to predict ones own thoughts, feelings, and choices in hypothetical situations. Again, theory and simulation can be used for doing this. The project was able to demonstrate the use of simulation for some specific cases. For instance, if people have to predict how much they will recall from a learning list, they simulate recall: judgments of learning thus are the result of simulated recall. Likewise, judgments of the duration of some processes are simulations of exactly these processes. That is, for judging the duration of a process, this process is reused, constituting a case of simulation.Another goal was to investigate the limits of successful simulation and how simulation depends on the current physical and emotional situation of the simulator. The current situation has a bigger influence on predictions in case of simulation than in case of theory. We were able to show this for curiosity: people, who were (made to be) curious predicted much more curiosity for other people than predicted people who themselves were not curious.In sum, we showed that simulation is a useful prediction strategy that tends to be used in various situations. Our findings enable predictions about when people will use simulation rather than theory, and which biases are likely to result from reliance on a simulative prediction strategy. Practical applications abound: these findings offer a basis for developing decision aids in all situations, where own, or other, judgments and choices have to be predicted. Theoretical relationships exist to similar processes investigated mainly in social psychology, like social projection, egocentric bias, or false consensus.