Evidence for goal- and mixed evidence for false belief-based action prediction in 2- to 4-year-old children: A large-scale longitudinal anticipatory looking replication study.

Unsuccessful replication attempts of paradigms assessing children's implicit tracking of false beliefs have instigated the debate on whether or not children have an implicit understanding of false beliefs before the age of four. A novel multi-trial anticipatory looking false belief paradigm yielded evidence of implicit false belief reasoning in 3- to 4-year-old children using a combined score of two false belief conditions (Grosse Wiesmann, C., Friederici, A. D., Singer, T., & Steinbeis, N. [2017]. Developmental Science, 20(5), e12445). The present study is a large-scale replication attempt of this paradigm. The task was administered three times to the same sample of N = 185 children at 2, 3, and 4 years of age. Using the original stimuli, we did not replicate the original finding of above-chance belief-congruent looking in a combined score of two false belief conditions in either of the three age groups. Interestingly, the overall pattern of results was comparable to the original study. Post-hoc analyses revealed, however, that children performed above chance in one false belief condition (FB1) and below chance in the other false belief condition (FB2), thus yielding mixed evidence of children's false belief-based action predictions. Similar to the original study, participants' performance did not change with age and was not related to children's general language skills. This study demonstrates the importance of large-scaled replications and adds to the growing number of research questioning the validity and reliability of anticipatory looking false belief paradigms as a robust measure of children's implicit tracking of beliefs.

"I know what's inside because you showed me": Training 33-month-old children to attribute knowledge and ignorance to themselves and others.

The present study investigated the role of language in two-year-old children's early understanding of knowledge and ignorance. An intense microgenetic training consisting of 12 to 14 training sessions within six to seven weeks was conducted between 33 and 36 months. One training group experienced and participated in discourse about epistemic states in theoretically relevant situations which highlighted, for instance, the relation between seeing and knowing or contrasts between different people's knowledge states. The other training group was trained on complement syntax using sentence repetition tasks. An age-matched control group received no training. The complement syntax training was not effective in improving complement syntax competence more than in the other two groups. In contrast, the mental state training led to higher improvements in the mental state training group than in the other two groups on tasks assessing comprehension of the targeted concepts (e.g., comprehension of the seeing-knowing relation). The mental state training also had an effect on children's metacognitive awareness of their own ignorance which was, however, not independent of complement syntax competence assessed at 33 months. No effect was obtained on epistemic perspective-taking skills. Our findings indicate that the use of mental state language in discourse promotes children's acquisition of epistemic concepts even before their third birthday.

Does syntax play a role in Theory of Mind development before the age of 3 years?

Language plays an important role in Theory of Mind development. Specifically, longitudinal and training studies indicate that the acquisition of complement syntax has an effect on three- to five-year-old children's mastery of the concept of false belief. There is evidence for both a beginning explicit understanding of the mind and mastery of complement syntax in children before their third birthday. In the present study, we investigated longitudinally whether an early sensitivity to complement syntax is related to early development of Theory of Mind abilities in a sample of N = 159 German-speaking 27- to 36-month-old children. Children's sensitivity to formal properties of complement syntax at 33 months was associated with their perspective-taking skills and their metacognition of own ignorance three months later. This relation remained significant when controlling for the effects of general language abilities. Furthermore, children's sensitivity to complement syntax was concurrently related to their early false belief understanding. These findings support the view that complement syntax shares representational demands with an understanding of epistemic states and that language begins to support the acquisition of epistemic concepts earlier than was previously thought.

33-month-old children succeed in a false belief task with reduced processing demands: A replication of Setoh et al. (2016).

A recent low-inhibition false belief task showed a high success rate with 33-month-old children when response-generation demands were reduced [Setoh, Scott, & Baillargeon (2016). Proceedings of the National Academy of Sciences, 113(47), 13360-13365]. We found correct responding in 74% of N = 58 33-month-old children, replicating the original findings. Within the same sample, we compared this performance with performance in a concurrent measure of false belief understanding which has previously produced competence in children below the age of 3 years [Hughes & Ensor (2007). Developmental Psychology, 43(6), 1447-1459]. Contrasting sharply with findings from the low-inhibition false belief task, we found partial competence in 15%, and full competence in only 5% of the same sample. These results show that the paradigm by Setoh and colleagues generates reliable findings in a different lab and a different language. We discuss this pattern of results in relation to theoretical considerations of early false belief understanding.

Enter the Wild: Autistic Traits and Their Relationship to Mentalizing and Social Interaction in Everyday Life.

Theories derived from lab-based research emphasize the importance of mentalizing for social interaction and propose a link between mentalizing, autistic traits, and social behavior. We tested these assumptions in everyday life. Via smartphone-based experience sampling and logging of smartphone usage behavior we quantified mentalizing and social interaction in our participants' natural environment. Mentalizing occurred less frequently than reasoning about actions and participants preferred to mentalize when alone. Autistic traits were negatively correlated with communication via smartphone. Yet, they were not associated with social media usage, a more indirect way of getting in touch with others. Our findings critically inform recent theories on social cognition, social behavior, and the role of autistic traits in these phenomena.