No links between genetic variation and developing theory of mind: A preregistered replication attempt of candidate gene studies.

Genetic variability is being discussed as a source of inter-individual differences in Theory of Mind development. Previous studies documented an association between variations in DRD4 VNTR 48 bp, OXTR rs53576, COMT rs4680, and Theory of Mind task performance. As empirical evidence on these associations is sparse, we conducted a preregistered replication attempt of a study reporting a link between DRD4 VNTR 48 bp and false belief understanding in 50-month-old children [Lackner, C., Sabbagh, M. A., Hallinan, E., Liu, X., & Holden, J. J. (2012). Developmental Science, 15(2), 272-280.]. Additionally, we attempted a replication of studies on the role of OXTR rs53576 and COMT rs4680 in Theory of Mind. In both replication attempts, we did not find any evidence for associations between the sampled genetic markers and Theory of Mind ability in a series of analyses. Extending the replication attempt of Lackner et al., we employed longitudinal data from several tasks and measurement points, which allowed us to run follow-up robustness checks with more reliable scores. These extensive analyses corroborated our null finding. This comprehensive non-replication is important to balance current research on genetic markers of Theory of Mind. In a combined evaluation of our own and previous studies, we point to substantial methodological issues that research on the genetic basis of Theory of Mind development faces. We conclude that these limitations currently prevent firm conclusions on genetic influences on Theory of Mind development.

Direct and indirect admission of ignorance by children.

Research has shown that children are able to admit their own ignorance directly (i.e., verbally) by 3years of age when they are totally ignorant about what is hidden in a box (total ignorance task) but fail to do so until 5 or 6years of age when having seen different objects without seeing which of them is being hidden (partial exposure task). This study investigated whether an earlier understanding of own ignorance in the partial exposure task is found when using an indirect measure-when children are allowed to either opt out from a risky decision (Experiment 1) or seek clarifying information by peeking inside (Experiment 2). No evidence for an earlier understanding was found in Experiment 1. In Experiment 2, however, 3- and 4-year-olds searched for clarifying information under partial exposure more often when being ignorant than when being knowledgeable. We argue that this discrepancy is related to whether spontaneous information seeking involves metacognitive processes or not.

Escape from metaignorance: how children develop an understanding of their own lack of knowledge.

Previous research yielded conflicting results about when children can accurately assess their epistemic states in different hiding tasks. In Experiment 1, ninety-two 3- to 7-year-olds were either shown which object was hidden inside a box, were totally ignorant about what it could be, or were presented with two objects one of which was being put inside (partial exposure). Even 3-year-olds could assess their epistemic states in the total ignorance and the complete knowledge task. However, only children older than 5 could assess their ignorance in the partial exposure task. In Experiment 2 with one hundred and one 3- to 7-year-olds, similar results were found for children under 5 years even when more objects were shown in partial exposure tasks. Implications for children's developing theory of knowledge are discussed.

Knowing minds: Linking early perspective taking and later metacognitive insight.

Recent metacognitive research using a partial knowledge task indicates that a firm understanding of 'knowing about knowing' develops surprisingly late, at around 6 years of age. To reveal the mechanisms subserving this development, the partial knowledge task was used in a longitudinal study with 67 children (33 girls) as an outcome measure at 5;9 (years;months). In addition, first- and second-order false belief was assessed at 4;2, 5;0, and 5;9. At 2;6, perspective taking and executive abilities were evaluated. Metacognition at 5;9 was correlated with earlier theory of mind and perspective taking - even when verbal intelligence and executive abilities were partialled out. This highlights the importance of perspective taking for the development of an understanding of one's own mind.

Retro- and prospection for mental time travel: emergence of episodic remembering and mental rotation in 5- to 8-year old children.

We investigate the common development of children's ability to "look back in time" (retrospection, episodic remembering) and to "look into the future" (prospection). Experiment 1 with 59 children 5 to 8.5 years old showed mental rotation, as a measure of prospection, explaining specific variance of free recall, as a measure of episodic remembering (retrospection) when controlled for cued recall. Experiment 2 with 31 children from 5 to 6.5 years measured episodic remembering with recall of visually experienced events (seeing which picture was placed inside a box) when controlling for recall of indirectly conveyed events (being informed about the pictures placed inside the box by showing the pictures on a monitor). Quite unexpectedly rotators were markedly worse on indirect items than non-rotators. We speculate that with the ability to rotate children switch from knowledge retrieval to episodic remembering, which maintains success for experienced events but has detrimental effects for indirect information.

Theory of Mind and diverse intelligences in 4-year-olds: Modelling associations of false beliefs with children's numerate-spatial, verbal, and social intelligence.

Theory of Mind (ToM) and the structure of intelligence were investigated in 115 4-year-olds. Specifically, we asked whether children's intelligence involves both general and specific aspects and whether standard ToM measures of false belief can serve as indicators of social intelligence. Psychometric intelligence and children's domain-specific understanding of number concepts and of mental states (false belief) were measured in the laboratory; communication and social skills were assessed through mothers' report. A confirmatory factor analysis revealed poor fit for a one-factor model, but good fit for a model with three correlated factors, suggesting that children's intelligence involves both general and specific aspects. Numerate-spatial and verbal intelligence were correlated (.70), and social intelligence correlated to a stronger degree with verbal (.66) than with numerate-spatial intelligence (.37). Laboratory assessment of false belief and mothers' reports about children's social skills loaded on a single factor, pointing to real-world consequences of ToM abilities. Statement of contribution What is already known on this subject? The structure of intelligence in 4-year-olds comprises domain-general and domain-specific dimensions. Some domain-specific dimensions are numerate-spatial, verbal, and social intelligence. What does this study add? Theory of Mind emerges as an aspect of children's social intelligence. Social intelligence (including Theory of Mind) is related to children's numerate-spatial abilities.

The developmental stability of inhibition from 2 to 5 years.

Executive functions or cognitive self-regulatory control processes are critical for children's ability to successfully navigate their academic and social environment. In this study, we focused on the development of one critical executive function skill, that of inhibitory control. In a longitudinal study, we tested 96 children at 24, 30, 36, 50, and 60 months of age with age-appropriate measures of inhibition. We found evidence for the developmental stability of inhibitory abilities. Inhibitory control at 30 months of age was strongly related to inhibitory control at 60 months of age even when verbal IQ was partialled out. Statement of contribution What is already known on this subject? Prior research has shown that executive functions play a key role in children's academic as well as social development. However, evidence on the stability of individual differences in executive functions, especially in preschool children, is sparse and contradictory. What the present study adds? The present work was designed to investigate the stability of one particular executive function, namely inhibitory control, over a relatively large period of time, from 24 to 60 months of age. The most important finding is a robust correlation between Reverse Categorization at 30 months and Simon Says at 60 months (r = .56). We argue that this further highlights the importance of early EF interventions due to a possible 'ripple effect'.

The direct way may not be the best way: Children with ADHD and their understanding of self-presentation in social interactions.

Knowledge and use of self-presentational tactics is an important social skill. We examined understanding of the function of three different self-presentational tactics (self-promotion, ingratiation and blasting) in 11 8-12-year-old boys with attention-deficit/hyperactivity disorder (ADHD) and 11 matched comparison children. Children were given six different self-presentation stories, two for each one of the three different tactics. After each story, they were asked to evaluate the effects of the self-presentational tactic used. Children with ADHD rated self-promotion and blasting as more positive and more effective-and ingratiation as less positive and less effective-than children in the control group. This implicates that children with ADHD prefer simple and direct self-presentational strategies (like self-promotion), and, therefore, may not as easily understand more subtle strategies (like ingratiation). They also seem to be more inclined to use negatively connoted strategies (like blasting). We suggest that this limited understanding of self-presentational strategies in children with ADHD may explain some of their problems in social interactions. Therefore, social skill interventions in children with ADHD should incorporate elements focusing on use and understanding of different self-presentational strategies.

Sorting between dimensions: conditions of cognitive flexibility in preschoolers.

The Dimensional Change Card Sorting task frequently is used to measure extradimensional shifting abilities in preschool children. In two studies, we investigated what makes this extradimensional shifting task difficult. In Study 1 with 61 2- to 4-year-olds, we showed that extradimensional shifts from one dimension to another are more difficult than reversal shifts within a dimension (even with irrelevant variation on a second dimension). Study 2 with 77 3- and 4-year-olds further confirmed this finding using a computerized paradigm and showed that sorting instructions are critical for 3-year-olds' difficulties with extradimensional shifts. This finding is taken to suggest that 3-year-olds have particular problems with spontaneously classifying one object in two different ways.

Disentangling dimensions in the dimensional change card-sorting task.

The dimensional change card-sorting task (DCCS task) is frequently used to assess young children's executive abilities. However, the source of children's difficulty with this task is still under debate. In the standard DCCS task, children have to sort, for example, test cards with a red cherry or a blue banana into two boxes marked with target cards showing a blue cherry and a red banana. Typically, 3-year-olds have severe problems switching from sorting by one dimension (e.g. color) to sorting by the other dimension (e.g. shape). Three experiments with 3- to 4-year-olds showed that separating the two dimensions as properties of a single object, and having them characterize two different objects (e.g. by displaying an outline of a cherry next to a red filled circle on the card) improves performance considerably. Results are discussed in relation to a number of alternative explanations for 3-year-olds' difficulty with the DCCS task.

Training transfer between card sorting and false belief understanding: helping children apply conflicting descriptions.

Two studies investigated the parallel developmental progress in theory of mind and executive control, as exemplified by correlations between the Dimensional Change Card Sorting task (DCCS; Frye, Zelazo, & Palfai, 1995) and the false-belief task. Experiment 1 with sixty 3-year-old children confirmed earlier studies (e.g., Perner & Lang, 2002), suggesting that children's problem with the DCCS lies in the redescription of stimulus objects. Experiment 2 with forty-four 3- to 4-year-olds reinforced the correlational evidence for a developmental link by showing transfer of training: False-belief training improved DCCS performance, and DCCS training significantly increased children's performance on the false-belief task. Results are discussed in relation to 5 theories explaining the existing correlational evidence.

Theory of mind and self-control: more than a common problem of inhibition.

This study tested the theory that advances on theory-of-mind tasks and on executive function tasks show a strong correlation because the typically used theory-of-mind tasks pose the same executive demands. In Experiment 1 with fifty-six 3- to 6-year-old children, performance on the dimensional change card-sorting task as an executive function task was correlated with performance on the usual false-belief prediction task, r = .65, and the false-belief explanation task, r = .65, as measures of theory-of-mind development. Because the explanation version of the false-belief test is supposed to be free of the alleged executive demands inherent in the prediction version, the equally strong correlation with the executive function task suggests that this correlation cannot be due to common executive demands. In Experiment 2, the basic finding of Experiment 1 was replicated on another sample of 73 children, ages 3 to 5.5 years. The need for new theories to explain the developmental link between theory of mind and executive function development is discussed, and some existing candidates are evaluated.