Actions really do speak louder than words—but only implicitly: Young children’s understanding of false belief in action Wendy A. Garnham Laboratory of Experimental Psychology, University of Sussex, UK Josef Perner* Department of Psychology, University of Salzburg, Austria Children show understanding of a mistaken story character’s actions in their visual- orienting responses before they show this in their answers to test questions. Clements and Perner (1994) interpreted the visual responses as reflecting implicit understanding (implicit-knowledge hypothesis). The present study explores three possible ways of saving the hypothesis that different bodies of exclusively explicit knowledge are involved (explicit-knowledge-only hypothesis): the lack-of-con- fidence hypothesis asserts that children are just not confident of the novel but correct answer and the misinterpretation hypothesis claims that children are simply misinterpreting the test question. The temporal stacking hypothesis assumes that children consider first the novel idea that the protagonist will go where he or she thinks the object is and then they consider the more established idea that the protagonist will go where the object really is. It explains the original finding by assuming that visual responses are governed by the earlier and the verbal answers by the later considered idea. The results offered little support for the first two of these attempts to save the explicit-knowledge-only hypothesis. Although parts of the results are compatible with the temporal stacking hypothesis, the overall pattern of results is not. Rather, it is very similar to findings from implicit visual perception, where people experience a lack of conscious awareness. This similarity reinforces the original interpretation of a dissociation between implicit and explicit understanding of belief-based action. The development of children’s theory of mind makes an important step with the understanding of misinformation, in particular the understanding of false belief. Although different tasks for assessing this understanding have some effect, overall the age trend is quite robust, located between 3 and 5 years (Wellman, Cross, & Watson, 2001). However, Clements and Perner (1994) reported a substantially earlier, but implicit , understanding of false belief. Such precocious, implicit understanding has also * Requests for reprints should be addressed to Dr. Josef Perner, Institute fu ¨ r Psychologie, University Salzburg, Hellbrunnerstrasse 34, A-5020 Salzburg, Austria. 413 British Journal of Developmental Psychology (2001), 19, 413–432 Printed in Great Britain # 2001 The British Psychological Society