Two sources of evidence on the non-automaticity of true and false belief ascription.

A recent study by Apperly et al. (2006) found evidence that adults do not automatically infer false beliefs while watching videos that afford such inferences. This method was extended to examine true beliefs, which are sometimes thought to be ascribed by "default" (e.g., Leslie & Thaiss, 1992). Sequences of pictures were presented in which the location of an object and a character's belief about the location of the object often changed. During the picture sequences participants responded to an unpredictable probe picture about where the character believed the object to be located or where the object was located in reality. In Experiment 1 participants were not directly instructed to track the character's beliefs about the object. There was a significant reaction time cost for belief probes compared with matched reality probes, whether the character's belief was true or false. In Experiment 2, participants were asked to track where the character thought the object was located, responses to belief probes were faster than responses to reality probes, suggesting that the difference observed in Experiment 1 was not due to intrinsic differences between the probes, but was more likely to be due to participants inferring beliefs ad hoc in response to the probe. In both Experiments 1 and 2, responses to belief and reality probes were faster in the true belief condition than in the false belief condition. In Experiment 3 this difference was largely eliminated when participants had fewer reasons to make belief inferences spontaneously. These two lines of evidence are neatly explained by the proposition that neither true nor false beliefs are ascribed automatically, but that belief ascription may occur spontaneously in response to task demands.