Individual Differences in Theory of Mind From Preschool to Adolescence: Achievements and Directions

Parents' mental state language and child gender: A scoping review of developmental evidence

Mental state language (MSL) is an important mechanism through which children learn about their social world and place within it. Previous research has suggested that parents may use MSL differently towards children based on their child's gender. However, findings are inconsistent. This scoping review explores the consistency of reported differences in parents' MSL use as a function of children's gender while exploring the methodological variables that may provide insights into these differences. Based on a review of the 27 studies included, 12 found a significant relationship between child gender and parents' MSL, while the remaining did not. The included studies used a range of methodological approaches to elicit MSL. This scoping review allows researchers and practitioners to reflect upon assumptions regarding the associations between child gender and parents' MSL. Further, we call for the use of diverse and informed approaches when studying these associations from a developmental perspective in the future.

Children's and adults' evaluations of self-enhancement and self-deprecation depend on the usual performance of the self-presenter

This study examined how evaluations of self-presentation vary with age depending on the self-presenter's usual performance. People's usual performance is a key factor because it generally influences the social evaluations and judgments that others make about them. Children aged 7 and 8 years (second graders) and 10 and 11 years (fifth graders), as well as adults, were presented with scenarios in which protagonists responded to praise after a good performance using either self-enhancement or self-deprecation. The other person in scenarios knew that the protagonist's usual performance on the task was either good or poor. After the protagonist responded to praise in a self-enhancing or self-deprecating way, the participants judged how the other person would evaluate the protagonist's ability (good/poor) and character (nice/mean). For ability evaluations specifically concerning protagonists who usually performed poorly, the results showed that by around 10 years of age children no longer tended to give more positive ability evaluations for self-enhancement than for self-deprecation. Adults gave less positive ability evaluations for self-deprecation than for self-enhancement, but only when the protagonists usually performed well. In relation to the character evaluations, by around 10 years of age self-enhancement led to less positive character evaluations than self-deprecation, but only when the protagonists usually performed poorly. Overall, second graders evaluated self-presenters as more competent and nicer. These results indicate that the expected evaluation of self-enhancement and self-deprecation is influenced by the usual level of performance but that there are developmental changes in this aspect of social cognition.

Longitudinal relations between theory of mind and academic achievement among deaf and hard-of-hearing school-aged children

This 2-year longitudinal study investigated the bidirectional relations between the development of theory of mind (ToM) and academic competences in a sample of 270 deaf and hard-of-hearing (DHH) children (Mage at Wave 1 = 7.52 years, SD = 0.99; 58.5% boys and 41.5% girls). Across three waves (10 months apart), children were assessed for their ToM abilities, using the ToM scale and a second-order false belief task, as well as for their language and mathematics skills. Cross-lagged correlational analysis revealed significant bidirectional associations between ToM and academic achievement (language and mathematics). That is, ToM predicted academic achievement with similar strength as ToM development itself was predicted by academic achievement. Our results highlight the bidirectional nature of the association between ToM and academic achievement, and they show that ToM development plays a crucial role in DHH children's school functioning.

TANGO: A reliable, open-source, browser-based task to assess individual differences in gaze understanding in 3 to 5-year-old children and adults

Traditional measures of social cognition used in developmental research often lack satisfactory psychometric properties and are not designed to capture variation between individuals. Here, we present the TANGO (Task for Assessing iNdividual differences in Gaze understanding-Open); a brief (approx. 5-10min), reliable, open-source task to quantify individual differences in the understanding of gaze cues. Localizing the attentional focus of an agent is crucial in inferring their mental states, building common ground, and thus, supporting cooperation. Our interactive browser-based task works across devices and enables in-person and remote testing. The implemented spatial layout allows for discrete and continuous measures of participants' click imprecision and is easily adaptable to different study requirements. Our task measures inter-individual differences in a child (N = 387) and an adult (N = 236) sample. Our two study versions and data collection modes yield comparable results that show substantial developmental gains: the older children are, the more accurately they locate the target. High internal consistency and test-retest reliability estimates underline that the captured variation is systematic. Associations with social-environmental factors and language skills speak to the validity of the task. This work shows a promising way forward in studying individual differences in social cognition and will help us explore the structure and development of our core social-cognitive processes in greater detail.

Measures of individual differences in adult theory of mind: A systematic review

Theory of mind (ToM), the ability to understand and reason about mental states, has been extensively studied in young children and clinical populations. A growing interest in examining ToM in adults has emerged over the past two decades, but the extent to which existing measures are suitable for studying adults, especially in detecting individual differences, remains understudied. In this systematic review of 273 studies, 75 measures used to investigate individual differences in adults' ToM were identified. Their sensitivity to individual differences, reliability, and validity were examined. Results suggest that ceiling effects were prevalent, and there was limited evidence to establish the reliability or validity of these measures due to the lack of reports of psychometric properties. Interrelations among measures were inconsistent. These findings highlight the need for future empirical and theoretical work to broaden the evidence base regarding psychometric properties of measures, to develop new measures, and to lay out more specific hypotheses about the relevance of ToM for different social outcomes.

Holding multiple category representations: The role of age, theory of mind, and rule switching in children's developing cross-classification abilities

Cross-classification, the ability to categorize multifaceted entities in many ways, is a remarkable cognitive milestone for children. Past work has focused primarily on documenting the timeline for when children reach cross-classification competence. However, it is not well understood what cognitive factors underpin children's improvements. The current study aimed to examine the contributions of age, theory of mind, and rule switching to children's cross-classification development. We tested 3- to 5-year-old children (N = 75) using a cross-classification task, the Theory of Mind Task Battery, and the Three-Dimensional Change Card Sort test. The results revealed that age and theory of mind predict children's cross-classification over and above the effects of rule switching. The results also revealed that advanced-level theory of mind reasoning is a particularly strong predictor of cross-classification development. These findings increase understanding of cross-classification within children's broader cognitive development.

Atypical Interpersonal Problem-Solving and Resting-state Functional Connectivity in Adolescents with Maltreatment Experience

BACKGROUND

Childhood maltreatment is associated with altered neurocognitive functioning, which is thought to reflect, in part, adaptation to early adverse environmental experiences. However, we continue to lack a precise mechanistic understanding linking atypical neurocognitive processing with social functioning and psychiatric outcomes following early adversity.

OBJECTIVE

The present work investigated interpersonal problem-solving, resting-state functional connectivity (rsFC), and mental health symptoms in adolescents with documented maltreatment experience and explored whether altered neural function contributes in part to poorer social functioning.

METHODS

Forty adolescents (aged 12-17) with documented experiences of abuse or neglect and a carefully matched group of 42 non-maltreated peers participated in this study that measured task-based interpersonal problem-solving skills and rsFC.

RESULTS

Adolescents with maltreatment experience showed poorer interpersonal problem-solving performance, which partly accounted for their elevated mental health symptoms. Resting-state seed-based analyses revealed that adolescents with maltreatment experience showed a significant increase in rsFC between medial Default Mode Network (DMN) hubs, the medial prefrontal cortex (mPFC), with a posterior cluster, including the posterior cingulate cortex (PCC), precuneus (PCu), retrosplenial cortex (RSC), and lingual gyrus (LG). Moderation analyses revealed that maltreatment-related increased DMN rsFC partly accounted for poorer performance in interpersonal problem-solving.

CONCLUSION

Poorer interpersonal problem-solving, partly accounted for by atypical coupling between DMN medial hubs, was associated with maltreatment exposure. Interventions tailored to enhance interpersonal problem-solving represents a promising avenue to promote resilience and reduce the likelihood of mental health disorder following maltreatment experience.

Assessing the construct validity of a theory of mind battery adapted to Tunisian school-aged children

Background

Theory of mind (ToM) refers to the ability to understand others' states of mind, desires, emotions, beliefs, and intentions to predict the content of their mental representations. Two major dimensions within ToM have been studied. The first is the type of inferred mental state, which can be cognitive or affective. The second comprises the types of processes involved according to their degree of complexity (first- and second-order false belief and advanced ToM). ToM acquisition is fundamental-a key component in the development of everyday human social interactions. ToM deficits have been reported in various neurodevelopmental disorders through various tools assessing disparate facets of social cognition. Nevertheless, Tunisian practitioners and researchers lack a linguistically and culturally appropriate psychometric tool for ToM assessment among school-aged children.

Objective

To assess the construct validity of a translated and adapted French ToM Battery for Arabic-speaking Tunisian school-aged children.

Methods

The focal ToM Battery was designed with neuropsychological and neurodevelopmental theory and composed of 10 subtests distributed evenly in three parts: Pre-conceptual, cognitive, and affective ToM. Translated and adapted to the Tunisian sociocultural context, this ToM battery was individually administered to 179 neurotypical Tunisian children (90 girls and 89 boys) aged 7-12 years.

Results

After controlling for the age effect, construct validity was empirically confirmed on two dimensions (cognitive and affective) via structural equation modeling (SEM) analysis, demonstrating that this solution has a good fit. The results confirmed that the age affected differentially the performance obtained on ToM tasks based on the two components of the battery.

Conclusion

Our findings confirm that the Tunisian version of the ToM Battery has robust construct validity for the assessment of cognitive and affective ToM in Tunisian school-aged children; hence, it could be adopted in clinical and research settings.

The complex associations between scientific reasoning and advanced theory of mind

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 end-of-elementary-school variance. Individual but not developmental differences were related to language abilities (0.39), mindreading skills (0.33), and parental education (0.36). In early elementary school, mindreading skills predicted scientific reasoning (0.15), but not vice versa; in late elementary school, bidirectional associations emerged (0.11-0.33). Our findings suggest that mindreading is a precursor for the development of scientific reasoning and that older children use scientific reasoning to revise their advanced theories of mind.

Accuracy of COVID-19 relevant knowledge among youth: Number of information sources matters

Can comics effectively convey scientific knowledge about COVID-19 to youth? What types and how many sources of information did youth have about COVID-19 during the pandemic? How are sources of information associated with accurate COVID-19 knowledge? To answer these questions, we surveyed youth in grades 5-9 in a Midwestern United States school district in the winter of 2020-2021. The online survey used measures of COVID-19 knowledge and sources, with an embedded experiment on COVID-19 relevant comics. Guided by an integrated science capital and just-in-time health and science information acquisition model, we also measured level of science capital, science identity, and utility of science for health and society. The school district protocol required parental consent for participation; 264 of ~15,000 youth participated. Youth were randomly assigned one of four comic conditions before receiving an online survey. Results indicate that, similar to knowledge gains in comic studies on other science topics, reading the comics was associated with 7 to 29% higher accuracy about COVID-19. We found that youth reported getting information about COVID-19 from between 0-6 sources including media, family, friends, school, and experts. The bivariate positive association of news versus other sources with accuracy of knowledge did not persist in the full model, yet the positive association of a higher number of sources and accuracy did persist in the multivariate models. The degree of valuing the utility of science for their health moderated the number of sources to accuracy association. Those with less value on science for health had a stronger positive association of number of sources and accuracy in COVID-19 knowledge. We conclude that during a pandemic, even with health and science information ubiquitous in the news media, increasing youth access to a variety of accurate sources of information about science and health can increase youth knowledge.

When did you stop speaking to yourself? Age-related differences in adolescents' world knowledge-based audience design

The ability to adapt utterances to the world knowledge of one's addressee is undeniably ubiquitous in human social cognition, but its development and association with other cognitive mechanisms during adolescence have not been studied. In an online production task, we measured the ability of children entering adolescence (ages 11-12, M = 11.8, N = 29 ,   17   girls ) and adolescents (ages 15-16, M = 15.9, N = 29 ,   17   girls ) to tailor referential expressions in accordance with the inferred world knowledge of their addressee-an ability we refer to as world knowledge-based audience design (AD). A post-test survey showed that both age groups held similar assumptions about the addressees' knowledge of referents, but the younger age group did not consistently adapt their utterances in accordance with these assumptions during online production, resulting in a significantly improved AD behaviour across age groups. We also investigated the reliance of AD on executive functions (EF). Executive functioning (as reflected by performance on the Wisconsin card sorting task) increased significantly with age, but did not explain the age-related increase in AD performance. We thus provide evidence in support of an adolescent development of world knowledge-based AD over and above development of EF.

Priming attachment and diversity ideologies: Effects on ethnic bias in children's altruistic sharing in a dictator game

Children often show a positive ingroup bias in altruistic behaviors such as sharing. Insight in factors related to ethnic bias in sharing can help towards understanding the origins of inequality in the distribution of resources in society. The present study examined the effect of priming secure attachment (versus positive affect) and multiculturalism (versus color-evasiveness) on ingroup bias in dominant ethnic group children's altruistic sharing. One hundred twenty-five White Dutch children (45 % boys, 55 % girls) between 7 and 11 years old (M_age = 8.47, SD_age = 0.87) participated in a Dictator game after being primed. The Dictator game was played against three same-gender children with different ethnic backgrounds (White, Black, Middle Eastern). Results support the idea that priming secure attachment and multiculturalism can decrease ingroup bias in dominant ethnic group children's altruistic sharing, although the effects do not strengthen each other and are effective in situations with different trade-offs and interaction partners. Future research is needed to disentangle the effectiveness of secure attachment and multiculturalism messages in different sharing situations and with interaction partners with different ethnic backgrounds. Results from the present study provide starting points from which to further examine which messages potentially positively impact children's interethnic relations.

Development of the mentalizing network structures and theory of mind in extremely preterm youth

Adolescents born preterm (<37 weeks of gestation) are at elevated risk for deficits in social cognition and peer relationships. Theory of Mind (ToM) is a complex form of social cognition important for regulating social interactions. ToM and the underlying mentalizing network continue to develop across adolescence. The present study recruited 48 adolescents (12-17 years old) who were either born extremely preterm (EPT; <28 weeks of gestation) or full-term (FT) at birth. Cortical thickness, gray matter volume and surface area were measured in four regions of the mentalizing network: the temporoparietal junction, anterior temporal cortex, posterior superior temporal sulcus and frontal pole (mBA10). We also assessed the adolescents' performance on a ToM task. Findings revealed both group differences and group-by-age interaction effects in the gray matter indices within the temporal lobe regions of the mentalizing network. The EPT group also performed significantly worse than the FT group on the ToM task. The cortical structural measures that discriminated the EPT and FT groups were not related to ToM performance. These results highlight altered developmental changes in brain regions underlying mentalizing functions in EPT adolescents relative to FT controls.

Advanced scaling and modeling of children’s theory of mind competencies: Longitudinal findings in 4- to 6-year-olds

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; Mage = 4.2; SD = 0.85 months; 68 girls, 87 boys) tests for the scalability of a broader range of ToM tasks, and we model the developmental transition from first-order to advanced ToM in 4- to 6-year-olds. Rasch analyses showed that psychometrically sound and developmentally sequenced scales emerge when measures of morally relevant and second-order false belief, as well as mental verb understanding, metacognition, and recognition of nonliteral speech are included. Individual differences were moderately stable over time, and there were systematic transitions from failure to success in children’s performance, suggesting that conceptual continuity exists between first-order and advanced ToM.

Household clutter and crowding constrain associations between maternal sensitivity and child theory of mind

Social interactions between parents and children are important for developing theory of mind, but these may be disrupted by aspects of the proximal home environment. The current study observed maternal sensitivity and its associations with child theory of mind and the housing environment (index by clutter and crowding) in a sample of mothers and their 3.5-year-old twins (N = 250 children). Maternal sensitivity and housing environment were measured from experimenter report and child theory of mind was measured through behavioural tasks. Results show that the association between maternal sensitivity and child theory of mind was moderated by the housing environment, where the positive associations between maternal sensitivity and child theory of mind were only observed at lower levels of clutter and crowding in the housing environment. Additional contextual variables and processes are discussed.

Theory of Mind and Peer Attachment in Adolescence

A growing body of research on theory of mind (ToM) highlights its significance for childhood social outcomes. Extending the developmental scope of this work, the current study investigated links between advanced ToM abilities and peer attachment in adolescence. Polish adolescents (16 to 18 years old; N = 302; 57.6% girls) completed two advanced ToM measures and reported on their peer attachment. With the effects of age and language controlled, girls scored higher than boys for both advanced ToM and peer attachment. However, the association between these measures was only significant in boys. These results are discussed in terms of theory and research on gender-specific approaches to social cognitive development in adolescence.

Does Advanced Theory of Mind Protect Primary-School Children from Loneliness? Longitudinal Relations from 9-10 Years

Advanced theory of mind (AToM) has been associated with several socioemotional consequences, including loneliness. However, the empirical evidence for this relation is mixed, with some studies finding no significant associations. The present study aimed to replicate and extend previous cross-sectional work. Specifically, we investigated the longitudinal associations between AToM and loneliness in late primary school [from grade 3 (G3) to grade 4 (G4)] by assessing 122 children for AToM (social reasoning) skills, loneliness and self-esteem (aged 9.06 ± .33 years, mean ± SD; 68 girls, 54 boys). Regression analyses showed that G4 loneliness was predicted by G3 self-esteem (β = .231, p <.05). However, in contrast with earlier findings, neither concurrent nor longitudinal associations emerged between AToM (social reasoning) and loneliness, suggesting that AToM alone affects children's real-world social functioning less than currently assumed.

Can theory of mind of healthy older adults living in a nursing home be improved? A randomized controlled trial

BACKGROUND

Research in nursing homes mainly focused on interventions for residents affected by cognitive decline. Few studies have considered healthy older adults living in nursing homes, and this research targeted cognitive functioning.

AIMS

To evaluate whether socio-cognitive abilities can be improved by means of a theory of mind (ToM) training conducted by nursing home's operators.

METHODS

RESULTS: Results revealed that older adults benefitted from the ToM intervention in both practiced and non-practiced tasks, while the control group showed no change from pre- to post-test evaluation. Analyses on errors scores indicated that the ToM intervention led to a reduction of both excessive mentalizing and absence of mental states inference.

DISCUSSION

The conversation-based ToM intervention proved to be effective in improving socio-cognitive skills in cognitively healthy nursing home residents. Notably, older adults were able to transfer the skills acquired during the training to new material.

CONCLUSIONS

Promoting healthy resident's ToM ability could positively impact on their social cognition, consequently increasing their quality of life. Our findings showed that the intervention can be feasibly managed by health care assistants within the residential context.

Measuring advanced theory of mind: Do story-based tasks work?

INTRODUCTION

Although much is known about theory of mind (ToM) development during childhood, data on how these skills develop in adolescence is scarce. This cavity is due in part to the limited knowledge about measures of advanced theory of mind.

METHODS

The study examined the relation among six common story-based tasks designed to measure advanced ToM in two age groups of Polish adolescents: early (13-year-olds; 78 girls) and late (16-year-olds; 143 girls) adolescents.

RESULTS

Factor models for individual tasks were constructed, followed by an examination of the underlying structure that explained the variability of factor scores. Only in half of the tasks, the results revealed an age-related increase in advanced ToM. Contrary to expectation, results showed a lack of correlations among story-based advanced ToM tasks in the two adolescent groups.

CONCLUSIONS

The results suggest a lack of coherence among advanced story-based ToM tasks and the need for further development of reliable and valid advanced ToM measures which are sensitive enough to show increasingly complex social reasoning abilities in adolescence.

But they weren't being careful! Role of theory of mind in moral judgments about victim and transgressor negligence

Previous research showed that children are influenced not only by intentions and outcomes but also by transgressor negligence in their moral judgments. The current study investigated the role of transgressor and victim negligence on children's moral judgments. Children's false-belief theory of mind understanding (FBU ToM) was examined as a possible factor that might shape moral judgments in contexts involving negligence. Children (N = 117, M_age = 5.41 years, range = 3-8) were presented with two stories involving property damage and physical harm where negligence was manipulated and with a series of questions assessing moral judgments regarding act acceptability of the transgressor and victim, punishment, and assessments of alternative actions. FBU ToM was measured with a false-content task. Children with higher FBU ToM were more likely to consider both transgressor and victim negligence in their moral judgments across different transgressions. The findings have implications for how social cognitive abilities interact with transgressor and victim negligence in moral decisions.

Willing and able? Theory of mind, social motivation, and social competence in middle childhood and early adolescence

This study investigated the links between theory of mind, social motivation, and children's social competence in middle childhood and early adolescence. Two hundred and sixty four children (136 girls, 128 boys) aged between 8 and 13 years (M Age = 10.88 years, SD = 1.45) completed theory-of-mind tests and self-report questionnaires measuring social motivation. Teachers rated children's social competence at school. Teacher-rated social competence was associated with individual differences in both theory of mind and children's motivation to develop and maintain social relationships. Results suggest that while individual differences in social motivation and theory of mind are partially overlapping, both theory of mind ability and social motivation contribute to successful social interaction at school.

The Development of Advanced Theory of Mind in Middle Childhood: A Longitudinal Study From Age 5 to 10 Years

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 elementary school, a multicomponent battery was used. Performance on many aspects of AToM was predicted by information-processing skills (intelligence and language at 6 years), but not by the age when children acquired the basic conceptual insight; only some naturalistic, social-interpretative tasks were correlated with children's age at acquisition. This study documents significant developmental progressions in middle-childhood AToM and suggests that different mechanisms may underlie diverse aspects of social cognition.

Advanced theory of mind in children with mild intellectual disability and deaf or hard of hearing children: A two-year longitudinal study in middle childhood

The present study investigates the development of advanced theory of mind (AToM) among typically developing (TD) children, children with mild intellectual disability (MID), and deaf or hard of hearing (DHH) children. The 2-year longitudinal study comprised three waves and included a large sample of children from Poland in middle childhood aged around 7.5-9.5 years (N = 779; M = 7.7, SD = 0.92 at wave 1). The analysis of children's understanding of second-order false belief and the Faux-Pas Recognition Test showed that TD children outperformed children with MID and DHH children on both measures. At 7.5 years, almost 60% of the TD children correctly solved the second-order false belief task; correct performance at 7.5 years in children with MID and DHH children was 27 and 38% respectively. Two years later, correct performance rose to 80% (TD children), 45% (children with MID), and 63% (DHH children). Despite these differences, the speed of AToM development did not differ across the groups. The development of faux-pas recognition followed a non-linear pattern, with TD children showing no further significant development after mid-elementary school. Our findings show differences in AToM development between TD children, children with MID, and DHH children, and they suggest that children's development of AToM may follow different developmental pathways, depending on the aspect of AToM under study.

Parental reflective functioning and theory of mind acquisition: A developmental perspective

This study investigated theory of mind (ToM) development in 83 children aged 3-5 years and its associations with parental reflective functioning (PRF), using a multidimensional and developmental approach. Results showed that ToM dimensions (i.e., affective, belief-desire, and cognitive) gradually increased with age. All dimensions of PRF (i.e., prementalizing modes, certainty about mental states, and interest and curiosity in mental states) were associated with ToM dimensions, with different dimensions being differentially related to ToM, including age-related effects.

Inhibitory Control and Preschoolers' Use of Irregular Past Tense Verbs

We investigated whether children's inhibitory control (IC) is associated with their ability to produce irregular past tense verb forms as well as learn from corrective feedback following overregularization errors. Forty-eight 3;6 to 4;5 year old children were tested on the irregular past tense and provided with adult corrective input via models of correct use or recasts of errors following ungrammatical responses. IC was assessed with a three-item battery of tasks that required suppressing a prepotent response in favor of a non-canonical one. Results showed that IC was associated with children's initial production of irregular forms, but not associated with their post-feedback production. Findings are discussed in terms of current theories of past tense use and acquisition.

Family Experiences and Parent Personality as Antecedents of Pubertal Timing in Girls and Boys

Pubertal timing may be influenced by typical variations in early family environmental events, but questions remain concerning the roles of specific parenting factors, developmental age of exposure to events, moderation by child temperament, and comparability of effects for girls and boys. This study focused on these questions utilizing longitudinal data from 733 same-sex twins (45% girls) in the U.S.; family context was measured at ages 1-3, 4-5, and 6-7 years and pubertal status was assessed annually via self-report at ages 9-15, enabling estimates of pubertal timing. Home environment at ages 4-5 years predicted pubertal timing better than home environment at other ages for both girls and boys, but parent personality was more predictive than home experiences (e.g., divorce, parental harshness, family conflict). Thus, effects of family environment must be considered within the context of parent characteristics, encouraging caution in implicating early environmental experiences as direct influences on early pubertal timing.

The Development of Identity Fusion

The fusion of personal and group identities can lead to self-sacrificial progroup behavior, from acts of charity to violent extremism. Two pathways to identity fusion-via shared biology and shared experiences-have been proposed. In this article, we elucidate a new developmental account of the origins and mechanisms of these two pathways to identity fusion from childhood to adulthood. Whereas fusion based on shared biology occurs from early childhood cued by phenotypic similarity, fusion based on episodic memories of shared experiences is not possible until midadolescence and relies on suitable bonding experiences (e.g., painful initiation rituals, emotionally intense team sports). The critical development that enables fusion based on shared experiences is autobiographical reasoning, which entails connecting one's past experiences to the present self. Autobiographical reasoning begins in adolescence, which may explain the flourishing of fusion in late adolescence and young adulthood relative to other life periods. Fusion via either pathway is linked to strong progroup behavior. We outline a program of empirical research on the development of identity fusion while addressing relevant methodological challenges. A developmental framework may help foster efforts to harness identity fusion for peaceful rather than violent forms of self-sacrifice for the group.

Children's and Adults' Beliefs about the Stability of Traits from Infancy to Adulthood: Contributions of Age and Executive Function

We examined developmental differences and sources of variability in trait reasoning. Four- to 10-year-olds and adults (N=198) rated how mean or nice "medium-mean" and "medium-nice" babies, kids, and teenagers were earlier in their lifetime and would be at older ages. Participants expected nice-labeled characters to be nice throughout their lives (participant age effects were null). In contrast, we documented age-related differences in judgments about meanness. With increasing participant age, individuals expected that meanness present in infancy, childhood, and adolescence would persist into adulthood. We discovered a curvilinear pattern in assessments of whether meanness originates during infancy: Four- to 5-year-olds and adults expected mean-labeled kids and teenagers to have been nicer as babies than did 6- to 10-year-olds. Controlling for age and working memory, participants with better inhibitory control more frequently expected mean-labeled individuals to remain mean across the lifespan, but inhibitory control was unrelated to judgments about nice-labeled individuals.

Reduced neural selectivity for mental states in deaf children with delayed exposure to sign language

Language provides a rich source of information about other people's thoughts and feelings. Consequently, delayed access to language may influence conceptual development in Theory of Mind (ToM). We use functional magnetic resonance imaging and behavioral tasks to study ToM development in child (n = 33, 4-12 years old) and adult (n = 36) fluent signers of American Sign Language (ASL), and characterize neural ToM responses during ASL and movie-viewing tasks. Participants include deaf children whose first exposure to ASL was delayed up to 7 years (n = 12). Neural responses to ToM stories (specifically, selectivity of the right temporo-parietal junction) in these children resembles responses previously observed in young children, who have similar linguistic experience, rather than those in age-matched native-signing children, who have similar biological maturation. Early linguistic experience may facilitate ToM development, via the development of a selective brain region for ToM.

Early Language Competencies and Advanced Measures of Mental State Understanding Are Differently Related to Listening and Reading Comprehension in Early Adolescence

The present study tests a section of the DIET (direct and indirect effects model of text comprehension; Kim, 2017) model and focuses on the relations between early language skills, various facets of mental state understanding, and text comprehension. In a sample of 267 children, I analyzed the relations between language skills (vocabulary, sentence comprehension) at age 3;6, theory of mind (ToM) at age 5;6, mental state language and metacognitive knowledge at age 9;2, and children's listening and reading comprehension of texts at age 13;7 years. For reading comprehension, results favored a total mediation model that included only direct links from metacognitive knowledge and mental state language to reading comprehension. For listening comprehension, by contrast, a model that also included direct relations from language and ToM in preschool was favored. Metacognitive skills did not mediate the relation between early skills and later text comprehension but, along with mental state language, showed direct relations with reading comprehension beyond listening comprehension. Early language skills showed various indirect relations with later reading comprehension via ToM, mental state language, and listening comprehension, whereas ToM showed only small indirect relations with later reading comprehension via later listening comprehension. These different relations of the various components with later listening in contrast to reading comprehension are discussed.

Theory of mind development from adolescence to adulthood: Testing the two-component model

The ability to infer mental and affective states of others is crucial for social functioning. This ability, denoted as Theory of Mind (ToM), develops rapidly during childhood, yet results on its development across adolescence and into young adulthood are rare. In the present study, we tested the two-component model, measuring age-related changes in social-perceptual and social-cognitive ToM in a sample of 267 participants between 11 and 25 years of age. Additionally, we measured language, reasoning, and inhibitory control as major covariates. Participants inferred mental states from non-verbal cues in a social-perceptual task (Eye Test) and from stories with faux pas in a social-cognitive task (Faux Pas Test). Results showed substantial improvement across adolescence in both ToM measures and in the covariates. Analysis with linear mixed models (LMM) revealed specific age-related growth for the social-perceptual component, while the age-related increase of the social-cognitive component fully aligned with the increase of the covariates. These results support the distinction between ToM components and indicate that adolescence is a crucial period for developing social-perceptual ToM abilities. Statement of contribution What is already known on this subject? To date, much research has been dedicated to Theory of Mind (ToM) development in early and middle childhood. However, only a few studies have examined development of ToM in adolescence. Studies so far suggest age-related differences in ToM between adolescents and young adults. What this study adds The study offers several methodological advantages including a large sample size with a continuous distribution of age (age 11-25) and the use of a comprehensive test battery to assess ToM and covariates (language, executive functions, reasoning). The results provide evidence for asymmetries in the development of two ToM components (social-perceptual and social-cognitive; the two-component account) across the studied age range: the social perceptual component showed specific development, while the age-related increase of the social-cognitive component fully aligned with increase of the covariates. Adolescence is a crucial period for developing social-perceptual ToM abilities.

Theory of mind, language, and reading: Developmental relations from early childhood to early adolescence

This study longitudinally investigated the relation between theory of mind (ToM) and verbal language skills in 231 children from preschool to early adolescence. Further, links to reading comprehension of texts at age 13;7 (years;months) were examined. To assess ToM, children completed false belief tasks at 5;6 and the Strange Stories at 12;8. To assess language, children completed a receptive grammar/sentence comprehension test at 3;6 and 5;6, a receptive vocabulary test at 3;6, 5;6 and 12;8, as well as a test of listening comprehension of texts at 13;7. A bidirectional relation between early and advanced measures of children's language skills and ToM was found: Changes in ToM were predicted by language skills, especially by receptive grammar/sentence comprehension; changes in children's receptive vocabulary were predicted by early ToM. However, early ToM had no direct or indirect effect on later listening comprehension or reading comprehension after controlling for early language skills. Only children's advanced ToM had a small indirect effect on reading comprehension, via listening comprehension. The results are discussed in light of ToM stability over time, and theories on how language and ToM development are intertwined.

Secret of the Masters: Young Chess Players Show Advanced Visual Perspective Taking

Playing chess requires perspective taking in order to consistently infer the opponent's next moves. The present study examined whether long-term chess players are more advanced in visual perspective taking tasks than their counterparts without chess training during laboratory visual perspective taking tasks. Visual perspective taking performance was assessed among 11- to 12-year-old experienced chess players (n = 15) and their counterparts without chess training (n = 15) using a dot perspective task. Participants judged their own and the avatar's visual perspective that were either consistent with each other or not. The results indicated that the chess players out-performed the non-chess players (Experiment 1), yet this advantage disappeared when the task required less executive functioning (Experiment 2). Additionally, unlike the non-chess players whose performance improved in Experiment 2 when the executive function (EF) demand was reduced, the chess players did not show better perspective taking under such condition. These findings suggested that long-term chess experience might be associated with children's more efficient perspective taking of other people's viewpoints without exhausting their cognitive resources.

Advanced theory of mind uniquely contributes to children's multiple-text comprehension

This study examined the contribution of advanced theory of mind (AToM), operationalized as second- or higher-order recursive mentalistic reasoning, to multiple-text comprehension in fourth and fifth graders (N = 184). The role of AToM was analyzed by taking into account children's individual characteristics (i.e., age, gender, prior topic knowledge, word reading fluency, vocabulary knowledge, and single-text comprehension) and task features (i.e., contrast between positions on the topic of two sets of texts). Mixed models analysis revealed that AToM uniquely contributed to comprehension of multiple texts over and above the individual and task variables. In addition, the contribution of AToM to the comprehension of multiple texts did not significantly differ for the two tasks despite differences in contrast between positions on the topic. Results indicate that children's ability to consider different perspectives and mental states is a relevant unique predictor of multiple-text comprehension.

Parent-child mentalizing in pediatric epilepsy

BACKGROUND

Child psychopathology involves inappropriate or biased attributions of others' mental states (mentalizing), and parents' assessment of their children's mentalizing significantly predicts the latter's psychosocial outcomes. Behavioral difficulties are frequent in children with epilepsy (CWE) yet biased mentalizing and parental accuracy in understanding their child's mental states reasoning have not been addressed.

METHODS

This study compared the performance of 34 CWE aged 9 to 16 years with 67 language age-matched controls on a biased mentalizing task. The task required children to infer on the mental states of peers in stories involving social scenarios. Responses were scored as positive, negative, or rational mentalizing attributions. To measure parental accuracy, a parent version was administered in the patient group that required a parent to identify their child's responses correctly. Relationships with the child's cognitive, behavioral, and epilepsy-related factors were examined.

RESULTS

Patients made greater negative mental states attributions compared with control children. This negative mentalizing bias was accurately identified by parents and was associated with children's behavioral problems. Parental accuracy was reduced for patients with lower cognitive abilities. Parents did not accurately identify an overly positive (OP) bias in their child's mental states attributions. Children's positive response bias correlated with their lower executive function (EF) skills. Epilepsy factors predicted cognitive deficits but not biased mentalizing or behavioral problems.

CONCLUSION

Biased mentalizing characterizes social cognition in CWE with behavioral problems. Further investigation of the mentalizing biases and parental awareness of children's mental states reasoning is required to fully understand the greater psychosocial and behavioral difficulties found in CWE.

The interaction between oxytocin receptor gene methylation and maternal behavior on children's early theory of mind abilities

Theory of mind, the ability to represent the mental states of others, is an important social cognitive process, which contributes to the development of social competence. Recent research suggests that interactions between gene and environmental factors, such as oxytocin receptor gene (OXTR) polymorphisms and maternal parenting behavior, may underlie individual differences in children's theory of mind. However, the potential influence of DNA methylation of OXTR remains unclear. The current study investigated the roles of OXTR methylation, maternal behavior, and their statistical interaction on toddlers' early emerging theory of mind abilities. Participants included a community sample of 189 dyads of mothers and their 2- to 3-year-old children, whose salivary DNA was analyzed. Results indicated that more maternal structuring behavior was associated with better performance, on a battery of three theory of mind tasks, while higher OXTR methylation within exon 3 was associated with poorer performance. A significant interaction also emerged, such that OXTR methylation was related to theory of mind among children whose mothers displayed less structuring, when controlling for children's age, sex, ethnicity, number of child-aged siblings, verbal ability, and maternal education. Maternal structuring behavior may buffer the potential negative impact of hypermethylation on OXTR gene expression and function.

The Two-Systems Account of Theory of Mind: Testing the Links to Social- Perceptual and Cognitive Abilities

According to the two-systems account of theory of mind (ToM), understanding mental states of others involves both fast social-perceptual processes, as well as slower, reflexive cognitive operations (Frith and Frith, 2008; Apperly and Butterfill, 2009). To test the respective roles of specific abilities in either of these processes we administered 15 experimental procedures to a large sample of 343 participants, testing ability in face recognition and holistic perception, language, and reasoning. ToM was measured by a set of tasks requiring ability to track and to infer complex emotional and mental states of others from faces, eyes, spoken language, and prosody. We used structural equation modeling to test the relative strengths of a social-perceptual (face processing related) and reflexive-cognitive (language and reasoning related) path in predicting ToM ability. The two paths accounted for 58% of ToM variance, thus validating a general two-systems framework. Testing specific predictor paths revealed language and face recognition as strong and significant predictors of ToM. For reasoning, there were neither direct nor mediated effects, albeit reasoning was strongly associated with language. Holistic face perception also failed to show a direct link with ToM ability, while there was a mediated effect via face recognition. These results highlight the respective roles of face recognition and language for the social brain, and contribute closer empirical specification of the general two-systems account.