This 6-wave longitudinal study (2014-2018) of 161 German 5- to 10-year-olds from a midsized city and rural area in southern Germany (89 females, 72 males; predominantly White; mostly middle class) found that scientific-reasoning abilities first develop at 6 years. Abilities were highly stable, with the kindergarten score predicting 25% of…

The metarepresentational aspect of early pretend play (make-believe activities where children create or participate in creating a new situation different from a real one) has been theoretically debated. In the present longitudinal study of N = 83 children, we tested for predictive relations of shared attention at 12-18 months, implicit false…

In a longitudinal study (N = 54), we investigated the developmental relation between children's implicit and explicit theory of mind and executive functions. We found that implicit false belief understanding at 18 months was correlated with explicit false belief understanding at 4 to 5 years of age, with the latter being closely related to…

This 5-year longitudinal study investigated advanced theory-of-mind (AToM) development in 161 German 5- to 10-year-olds (89 females, 72 males). Core aspects of AToM developed nonlinearly, with children reaching a milestone at the age of 7 years, around when they attained the conceptual insight that mental states can be recursive. In late…

It has been argued that the distinction between factivity and non-factivity is more fundamental to mental state understanding than that between false beliefs and reality. The present study examined children's growing understanding of all possible contrasts between the factive verb "know" and the non-factive verbs "think" and…

Identifying correlates of aggressive behavior in children might help to find potential candidates for interventions in aggression reduction. While some previous studies found that children's Theory of Mind (ToM) and inhibitory control (IC) correlate with aggressive behavior, others did not confirm this relation. One explanation for these mixed…

First-order theory of mind (ToM) development has shown to conform to a Guttman scale, with desire reasoning developing before belief reasoning. There have been attempts to test for internal consistency and scalability in advanced ToM, but not over a broad age range and only with a limited set of tasks. This 2-year longitudinal study (N = 155;…

Early scientific thinking in kindergarten (6-year-olds) was investigated in a large study involving 227 participants. We investigated (1) whether individual differences across 3 scientific-thinking components (experimentation, data interpretation, and understanding the nature of science) are stable across children, (2) whether children's increased…

Theory of Mind (ToM), the ability to attribute mental states to agents, has usually been measured with explicit verbal tasks and found to develop slowly during the preschool years. New implicit ToM measures have lately revolutionized the field by suggesting that ToM may be present much earlier in development. However, recent replication studies of…

Pretend play may be beneficial for young children's social development. However, empirical results to date are inconsistent and limited, which is partly due to a lack of psychometrically sound measures for children's social pretend play competence. The current study aimed to compare and validate different assessment methods for children's social…

First-order and advanced theory of mind (ToM and AToM), and their structures and relations were investigated in 229 children aged 5-8 years. ToM was assessed using 6 tasks from the first-order ToM scale, while AToM was measured using an 18-item battery (higher-order false-belief understanding; strange stories; faux pas test; eyes test;…

Theory of mind is one of the most important cognitive factors in social information-processing, and deficits in theory of mind have been linked to aggressive behavior in childhood. The present longitudinal study investigated reciprocal links between theory of mind and two forms of aggression--physical and relational--in middle childhood with three…

Do social cognition and epistemological understanding promote elementary school children's experimentation skills? To investigate this question, 402 children (ages 8, 9, and 10) in 2nd, 3rd, and 4th grades were assessed for their experimentation skills, social cognition (advanced theory of mind [AToM]), epistemological understanding (understanding…

Previous cross-cultural research using false-belief tasks has explored whether children's theory of mind develops synchronously across cultures. Success on false-belief tasks is usually interpreted as an important indicator of children's mental state understanding, but inconsistent findings have led to questions regarding the interpretation of…

Theories of social-cognitive development have attributed a foundational role to declarative joint attention. The present longitudinal study of 83 children, who were assessed on a battery of social-cognitive tasks at multiple measurement points from the age of 12 to 50 months, tested a predictive model of theory of mind (false-belief…