The knowledge ("true belief") error in 4- to 6-year-old children: When are agents aware of what they have in view?

Published: 20 June 2022| Version 1 | DOI: 10.17632/3jk5pmnfc3.1
, Sarah Leikard,
, Anna Mangstl,


The standard view on explicit theory of mind development holds that children around the age of 4 years start to ascribe beliefs to themselves and others, typically tested with false belief (FB) tasks. The present study (N = 95, 53 female, Austrian, 41 to 80 months) systematically investigated the puzzling phenomenon that FB achievers (FB+) fail knowledge (often subsumed under “true belief”) tasks: Despite the story protagonist witnessing the displacement of an object these children predict that the protagonist will look for it in its original location. We replicate this result in Experiment 1. Interestingly, some of our children indicated uncertainty about the protagonist’s awareness of the relevant event. Thus, in Experiment 2 a new active watching condition was designed to help children understand that the protagonist attended to the critical event. This practically eradicated the knowledge error. Experiment 3 successfully replicated these results. Implications for existing explanations, perceptual access reasoning (PAR, Fabricius, et al., 2010) and pragmatic difficulties (Oktay-Gür and Rakoczy, 2017) are discussed.


Steps to reproduce

We used three animated stories for each child (also used in Perner, Mauer & Hildenbrand, 2011; Priewasser, Fowles, Schweller & Perner, 2020; Priewasser, Roessler & Perner, 2013) which were presented on a laptop. Each child faced one standard change-of-location FB and two knowledge tasks of the same structure as the FB task except that the protagonist was present when the object was transferred. The two knowledge tasks differed with respect to the timing of object transfer and posing the test question; the test question followed either immediately or with a delay. For further details see the article.


Universitat Salzburg


Knowledge, Theory of Mind