Differential susceptibility to rearing environment depending on dopamine-related genes: new evidence and a meta-analysis

Examining the associations between microglia genetic capacity, early life exposures and white matter development at the level of the individual

There are inter-individual differences in susceptibility to the influence of early life experiences for which the underlying neurobiological mechanisms are poorly understood. Microglia play a role in environmental surveillance and may influence individual susceptibility to environmental factors. As an index of neurodevelopment, we estimated individual slopes of mean white matter fractional anisotropy (WM-FA) across three time-points (age 4.5, 6.0, and 7.5 years) for 351 participants. Individual variation in microglia reactivity was derived from an expression-based polygenic score(ePGS) comprised of Single Nucleotide Polymorphisms (SNPs) functionally related to the expression of microglia-enriched genes.A higher ePGS denotes an increased genetic capacity for the expression of microglia-related genes, and thus may confer a greater capacity to respond to the early environment and to influence brain development. We hypothesized that this ePGS would associate with the WM-FA index of neurodevelopment and moderate the influence of early environmental factors.Our findings show sex dependency, where a significant association between WM-FA and microglia ePGS was only obtained for females.We then examined associations with perinatal factors known to decrease (optimal birth outcomes and familial conditions) or increase (systemic inflammation) the risk for later mental health problems.In females, individuals with high microglia ePGS showed a negative association between systemic inflammation and WM-FA and a positive association between more advantageous environmental conditions and WM-FA. The microglia ePGS in females thus accounted for variations in the influence of the quality of the early environment on WM-FA.Finally, WM-FA slopes mediated the association of microglia ePGS with interpersonal problems and social hostility in females. Our findings suggest the genetic capacity for microglia function as a potential factor underlying differential susceptibility to early life exposuresthrough influences on neurodevelopment.

Developmental cascades from early childhood attachment security to adolescent level of personality functioning among high-risk youth

This study examines associations between early childhood attachment security and adolescent personality functioning in a high-risk sample within a developmental psychopathology framework. Data from 2,268 children (1165 male; 1103 female) and caregivers participating in Future of Families and Child Well-Being Study (FFCWS) were used to examine (1) effects of genetic polymorphisms of the serotonin transporter (5-HTTLPR) and dopamine D4 receptor (DRD4) genes and adverse childhood experiences (ACEs) on attachment security and emotional and behavioral dysregulation in early childhood and (2) longitudinal associations and transactional relationships among attachment security, dysregulation, negative parenting attitudes and behaviors, social competence, and adolescent personality functioning. Results revealed that ACEs predicted attachment security over and above sex or the genetic risk, and gene × environment interactions did not increment prediction. Results of cascade models showed that greater early childhood attachment security predicted higher adolescent level of personality functioning via pathways through intermediary variables. Limitations and future research directions are discussed.

Developmental authenticity - underlying dynamics of inner work processes

An emerging body of research attends to grasp the concept of authenticity. Nonetheless, a view on the developmental part with its underlying facets of Inner Work processes, is rare. In this paper, we aim to take a deeper look into the dynamics of inner work processes, that define certain authenticity developmental stages. Building upon our recently proposed "4C-view" of authenticity, we approach this developmental perspective from two different angles: from a process characteristic angle and a developmental level angle. Using vignettes of authentic client personality coaching processes, we propose that the interwoven dynamic between those two aspects yields several combinations of maturity levels within the individual. Continuity as an overarching concept thus contains various developmental authenticity stages that could be identified through different markers and vary in particular contexts.

Individuals being high in their sensitivity to the environment: Are sensitive period changes in play?

All individuals on planet earth are sensitive to the environment, but some more than others. These individual differences in sensitivity to environments are seen across many animal species including humans, and can influence personalities as well as vulnerability and resilience to mental disorders. Yet, little is known about the underlying brain mechanisms. Key genes that contribute to individual differences in environmental sensitivity are the serotonin transporter, dopamine D4 receptor and brain-derived neurotrophic factor genes. By synthesizing neurodevelopmental findings of these genetic factors, and discussing them through the lens of mechanisms related to sensitive periods, which are phases of heightened neuronal plasticity during which a certain network is being finetuned by experiences, we propose that these genetic factors delay but extend postnatal sensitive periods. This may explain why sensitive individuals show behavioral features that are characteristic of a young brain state at the level of sensory information processing, such as reduced filtering or blockade of irrelevant information, resulting in a sensory processing system that 'keeps all options open'.

Annual Research Review: 'There, the dance is - at the still point of the turning world' - dynamic systems perspectives on coregulation and dysregulation during early development

During development we transition from coregulation (where regulatory processes are shared between child and caregiver) to self-regulation. Most early coregulatory interactions aim to manage fluctuations in the infant's arousal and alertness; but over time, coregulatory processes become progressively elaborated to encompass other functions such as sociocommunicative development, attention and executive control. The fundamental aim of coregulation is to help maintain an optimal 'critical state' between hypo- and hyperactivity. Here, we present a dynamic framework for understanding child-caregiver coregulatory interactions in the context of psychopathology. Early coregulatory processes involve both passive entrainment, through which a child's state entrains to the caregiver's, and active contingent responsiveness, through which the caregiver changes their behaviour in response to behaviours from the child. Similar principles, of interactive but asymmetric contingency, drive joint attention and the maintenance of epistemic states as well as arousal/alertness, emotion regulation and sociocommunicative development. We describe three ways in which active child-caregiver regulation can develop atypically, in conditions such as Autism, ADHD, anxiety and depression. The most well-known of these is insufficient contingent responsiveness, leading to reduced synchrony, which has been shown across a range of modalities in different disorders, and which is the target of most current interventions. We also present evidence that excessive contingent responsiveness and excessive synchrony can develop in some circumstances. And we show that positive feedback interactions can develop, which are contingent but mutually amplificatory child-caregiver interactions that drive the child further from their critical state. We discuss implications of these findings for future intervention research, and directions for future work.

The contribution of Sensory Processing Sensitivity and internalized attachment representations on emotion regulation competencies in school-age children

Introduction

As captured by the individual trait of Sensory Processing Sensitivity (SPS), highly sensitive children perceive, process, and responds more strongly to stimuli. This increased sensitivity may make more demanding the process of regulating and managing emotions. Yet, developmental psychology literature also showed that other variables, as those related to the rearing environment, are likely to contribute to the process of regulating emotions. With the current contribution, we aim to bridge two lines of research, that of attachment studies and that of SPS, by investigating the additive and interactive contribution of SPS and internal working models of attachment representations on emotion regulation competencies in school-aged children.

Method

Participants were N = 118 Italian children (mean age: 6.5, SD = 0.58 years, and 51.8% female) with their mothers. Children's positive attachment representations were rated observationally through the Manchester Child Attachment Story Task procedure during an individual session at school. Mothers reported on children SPS trait and emotion regulation competencies completing the Highly Sensitive Child Scale-parent report and the Emotion Regulation Checklist. We performed and compared a series of main and interaction effect models.

Results

SPS was not directly associated with emotion regulation but it was significantly associated with positive attachment representations in predicting emotion regulation. Highly sensitive children showed poorer emotion regulation when the internalized representations were low in maternal warmth and responsiveness. When driven by sensitive and empathic attachment representation, highly sensitive children showed better emotion regulation than less-sensitive peers, suggesting a for better and for worse effect.

Discussion

Highly sensitive children are not only more vulnerable to adversities but also show better emotion regulation competencies when supported by positive internal working models of attachment relationships. Overall, findings shed light on the link between SPS and attachment and suggest that working for promoting secure attachment relationships in parent-child dyads may promote better emotion regulation competences, particularly in highly sensitive children.

Serotonergic multilocus genetic variation moderates the association between interpersonal relationship and adolescent depressive symptoms

BACKGROUND

Research suggests that genetic variants linked to serotonin functioning moderate the association between environmental stressors and depressive symptoms, but examining gene-environment interactions with single polymorphisms limits power.

METHODS

A multilocus genetic profile score (MGPS) approach to measuring serotonergic multilocus genetic variation and examined interactions with interpersonal relationship, insomnia with depressive symptoms as outcomes in an adolescent sample (average age = 14.15 ± 0.63 years since first measurement; range: 13 to 15).

RESULTS

(1) interpersonal relationship predicted adolescent depressive symptoms; (2) insomnia mediated the effect of interpersonal relationships on adolescent depressive symptoms; (3) the THP2 gene rs4570625 polymorphism G allele was a key risk factor for depressive symptom, and the MGPS moderated the effects of teacher-student relationship and insomnia on adolescent depressive symptom. Specifically, as the MGPS increased, the effects of insomnia on adolescent depressive symptom were enhanced; further, when the MGPS score increased, the effect of teacher-student relationship on depression showed a similar phenomenon with an increased slope and enhanced prediction; and (4) the results of sensitivity analysis showed that multilocus genetic interaction with the environment had a better explanatory power and stability for depression than single polymorphism studies.

CONCLUSION

MGPS provides substantial power to examine gene-environmental interactions linked to affective outcomes among adolescents.

Practitioner Review: Differential susceptibility theory: might it help in understanding and treating mental health problems in youth?

Diathesis-stress models conceptualise individual differences in propensity for psychopathology as an interaction between environmental risk factors and intra-individual vulnerabilities. In contrast, the differential susceptibility theory and related frameworks view intra-individual differences as variations in sensitivity to the environments rather than merely vulnerability to them. Specifically, they suggest that more sensitive individuals are more affected by the quality of their context, whether positive or negative, than others who are less sensitive. Empirical research over the last two decades has found support for this notion in that greater sensitivity is associated with a greater risk of psychopathology in adverse contexts, but also with lower risk in positive environments. However, despite growing academic and public interest in this field, it is currently unclear to what extent the differential susceptibility model is relevant, or applicable, to clinical practice. The purpose of this review is to focus on the differential susceptibility theory as an alternative explanation of individual differences in mental health and examine its relevance in the treatment of mental health problems in young people. We provide an overview of differential susceptibility and related theories, and current relevant research in the field. We identify potential implications of differential susceptibility models for understanding and treating mental health problems in young people, whilst also highlighting important gaps in research that limit their application at present. Finally, we suggest directions for future research that will assist in the translation of differential susceptibility theories into clinical practice.

Exploring the interplay of dopaminergic genotype and parental behavior in relation to executive function in early childhood

Child genotype is an important biologically based individual difference conferring differential sensitivity to the effect of parental behavior. This study explored dopaminergic polygenic composite × parental behavior interactions in relation to young children's executive function. Participants were 135 36-month-old children and their mothers drawn from a prospective cohort followed longitudinally from pregnancy. A polygenic composite was created based on the number of COMT, DAT1, DRD2, and DRD4 alleles associated with increased reward sensitivity children carried. Maternal negative reactivity and responsiveness were coded during a series of structured mother-child interactions. Executive function was operationalized as self-control and working memory/inhibitory control. Path analysis supported a polygenic composite by negative reactivity interaction for self-control. The nature of the interaction was one of diathesis-stress, such that higher negative reactivity was associated with poorer self-control for children with higher polygenic composite scores. This result suggests that children with a higher number of alleles may be more vulnerable to the negative effect of negative reactivity. Negative reactivity may increase the risk for developing behavior problems in this population via an association with poorer self-control. Due to the small sample size, these initial findings should be treated with caution until they are replicated in a larger independent sample.

Environmental susceptibility for all: A data-driven approach suggests individual differences in domain-general and domain-specific patterns of environmental susceptibility

How we are influenced by our environment is a fundamental question in developmental science. Theories and empirical research have claimed that some individuals are susceptible to environmental influences and others are much less susceptible. The present study addressed four questions: (1) Is environmental susceptibility a continuous or categorical construct? (2) Is environmental susceptibility unidimensional (i.e., domain general) or multidimensional (i.e., domain specific)? (3) Are there genetic contributions to individual differences in environmental susceptibility? (4) What are the temperamental characteristics of different environmental susceptibility patterns? We used child- and mother-report data from a sample of 11-year-old twins (N = 1,507) and applied a novel data-driven approach to assess an environmental susceptibility space, based on simultaneous associations between multiple environmental exposures (18 measures relating to parenting, parent, peer, and twin relationships) and developmental outcomes (10 measures relating to empathy, prosocial behavior, aggression, and self-esteem). The results suggest that the environmental susceptibility space we assessed is better conceptualized as continuous and multidimensional. Different children showed susceptibility to different contexts and variation in domain-general versus domain-specific patterns. A comparison of distances between monozygotic and dizygotic twins within the space demonstrated genetic contributions. Finally, susceptibility patterns could not be differentiated based on a specific temperament trait, but rather related to temperament profiles.

Sensory processing sensitivity and social pain: a hypothesis and theory

Sensory-processing sensitivity (SPS) defined, as a personality trait, seems to be characterized by emotional sensitivity, and stronger reactivity to both external and internal stimuli. SPS can represent a risk factor for developing clinical conditions during childhood and adolescence. This personality trait is not to be considered a pathological clinical condition, however, can expose to greater environmental vulnerability. In particular, the recent studies about SPS can be contextualized to social situations that evoke traumatic and stressful emotional responses such as social exclusion. We hypothesize that highly sensitive people (HSP) are more vulnerable to social exclusion and social pain. This hypothesis could help structure new educational and intervention models designed to improve coping strategies and promote HSP's psychophysical and social well-being.

Epigenetic Analysis of the Dopamine Transporter Gene DAT1 with a Focus on Personality Traits in Athletes

Human phenotypes (traits) are determined by the selective use of a person's unique genotype (DNA sequence), following exposure to environmental stimuli, such as exercise. Inducing profound changes in epigenetics may be an underlying factor of the beneficial effects of exercise. This study aimed to investigate the association between methylation in the promoter region of the DAT1 gene and personality traits measured by the NEO-FFI questionnaire in a group of athletes. The study group included 163 athletes, and the control group consisted of 232 non-athletes. The obtained results show several significant differences between the studied groups of subjects. The Extraversion scale and the Conscientiousness scale results of the NEO-FFI are significantly higher in the group of athletes compared to controls. The total methylation and the number of methylated islands in the promoter region of the DAT1 gene are higher in the study group. Pearson's linear correlation between the total methylation, the number of methylated islands and the NEO-FFI shows significant results for the Extraversion and Agreeability scales. The total methylation and the number of methylated islands in the promoter region of the DAT1 gene are higher in the study group. Pearson's linear correlation between the total methylation, the number of methylated islands and the NEO-FFI shows significant results for the Extraversion and Agreeability scales. Our analysis of the methylation status of individual CpG sites revealed a new direction of research into the biological aspects of regulating dopamine release and personality traits in people practicing sports.

The impact of dopamine receptor D4, temperamental negativity, and household chaos on young twins' externalizing behaviors

Biological and genetic factors, as well as contextual influences, contribute to the etiology of externalizing behaviors in children and adolescents. The current project used a longitudinal design to examine how individual vulnerability for externalizing behavior is influenced by the interplay among biological/genetic and environmental factors, and how this occurs across development. We investigated the influence of dopamine receptor D4 genotype (DRD4), child temperament, and household chaos on children's externalizing behaviors using a sample of twins/triplets tested at the ages of 4 and 5 years (n = 229), including a subset of these who were tested again in middle childhood (ages 7-13 years; n = 174). Multilevel linear regression modeling demonstrated that the DRD4-7repeat genotype, 4-year-old negative affectivity, and household chaos at the age of 4 years were related to 5-year-old externalizing behaviors. Stability in externalizing behaviors from the age of 5 years to middle childhood was demonstrated. A significant interaction between DRD4 and household chaos showed that children with no 7-repeat DRD4 alleles had significantly higher levels of externalizing in homes with extremely low levels of parent-reported chaos, suggesting a "goodness-of-fit" pattern of gene-environment interaction. These findings suggest that risk for childhood externalizing behaviors is likely multifaceted and differs across developmental periods.

Factors related to the development of executive functions: A cumulative dopamine genetic score and environmental factors predict performance of kindergarten children in a go/nogo task

BACKGROUND

This study aimed at investigating the interaction between genetic and environmental factors in predicting executive function in children aged four to six years.

METHODS

Response inhibition as index of EF was assessed in 197 children using a go/nogo task. A cumulative dopamine (DA) genetic score was calculated, indexing predisposition of low DA activity. Dimensions of parenting behavior and parental education were assessed.

RESULTS

Parental education was positively related to accuracy in nogo trials. An interaction between the cumulative genetic score and the parenting dimension Responsiveness predicted go RT indicating that children with a high cumulative genetic score and high parental responsiveness exhibited a careful response mode.

CONCLUSION

The development of EF in kindergarten children is related to parental education as well as to an interaction between the molecular-genetics of the DA system and parenting behavior.

Biological sensitivity to context as a dyadic construct: An investigation of child-parent RSA synchrony among low-SES youth

Parenting behaviors are significantly linked to youths' behavioral adjustment, an association that is moderated by youths' and parents' self-regulation. The biological sensitivity to context theory suggests that respiratory sinus arrhythmia (RSA) indexes youths' varying susceptibility to rearing contexts. However, self-regulation in the family context is increasingly viewed as a process of "coregulation" that is biologically embedded and involves dynamic Parent×Child interactions. No research thus far has examined physiological synchrony as a dyadic biological context that may moderate associations between parenting behaviors and preadolescent adjustment. Using a two-wave sample of 101 low-socioeconomic status (SES) families (children and caretakers; mean age 10.28 years), we employed multilevel modeling to examine dyadic coregulation during a conflict task, indicated by RSA synchrony, as a moderator of the linkages between observed parenting behaviors and preadolescents' internalizing and externalizing problems. Results showed that high dyadic RSA synchrony resulted in a multiplicative association between parenting and youth adjustment. High dyadic synchrony intensified the relations between parenting behaviors and youth behavior problems, such that in the context of high dyadic synchrony, positive and negative parenting behaviors were associated with decreased and increased behavioral problems, respectively. Parent-child dyadic RSA synchrony is discussed as a potential biomarker of biological sensitivity in youth.

Added value of neurotechnology for forensic psychiatric and psychological assessment

The attention for neuroscience in relation to criminal behavior is growing rapidly, and research shows that neurobiological factors have added value to the understanding of psychological and social factors in explaining delinquency. There is evidence that neurotechnology can be used in criminal justice and may be of relevance for forensic psychiatric and psychological assessment. However, the question is whether scientific knowledge of neurobiological factors is applicable in daily practice of forensic assessment. Incorporation of basic technologies, e.g., psychophysiology (heart rate, skin conductance, wearables), hormonal measures (cortisol, testosterone), and neuropsychological testing might be evident, since they can be applied relatively easy. Moreover, a body of research shows the additive value of these technologies in this field. In addition, first steps are taken to apply these technologies in individual diagnostics, treatment, and risk assessment. Complex neurotechnologies like functional MRI (e.g., brain reading) and EEG show potential to be applicable in criminal justice, once it is known what additional information these indices offer for individual cases.

Parental rejection in early adolescence predicts a persistent ADHD symptom trajectory across adolescence

Despite a general decrease of attention-deficit/hyperactivity disorder (ADHD) symptoms during adolescence, these may persist in some individuals but not in others. Prior cross-sectional studies have shown that parenting style and their interaction with candidate genes are associated with ADHD symptoms. However, there is a lack of longitudinal research examining the independent and interactive effects of parenting and plasticity genes in predicting the course of attention-deficit/hyperactivity disorder (ADHD) symptoms across adolescence. Here, we investigated how children perceived their parents' parenting style (i.e., rejection, overprotection, and emotional warmth) at the age of 11, and their interaction with DRD4, MAOA, and 5-HTTLPR genotypes on parent-reported ADHD symptoms at three time points (mean ages 11.1, 13.4, and 16.2 years) in 1730 adolescents from the TRacking Adolescents' Individual Lives Survey (TRAILS). Growth Mixture Modeling in Mplus identified four ADHD symptom trajectories: low, moderate stable, high decreasing, and high persistent. Perceived parental rejection predicted class membership in the high persistent trajectory compared to the other classes (p < 0.001, odds ratios between 2.14 and 3.74). Gene-environment interactions were not significantly related to class membership. Our results indicate a role of perceived parental rejection in the persistence of ADHD symptoms. Perceived parental rejection should, therefore, be taken into consideration during prevention and treatment of ADHD in young adolescents.

From temperament and parenting to attachment: a review of the interplay of gene and environment factors in the developmental pathway to attachment

PURPOSE OF REVIEW

Attachment represents an aspect of the parent-child relationship by encapsulating behaviours and stress management strategies. Although attachment is not considered a measure of psychopathology, some attachment styles place children at higher risk for psychopathologies. The origins of attachment have historically thought to be either parenting-related variables, or temperament. More recently, there has been accumulated evidence of gene × environment interactions in attachment, temperament, and parenting. This review aims to cover shared gene × environment pathways between these variables, introduce recent relevant insights from prenatal programming research, and offer a synthesized developmental cascade model of attachment.

RECENT FINDINGS

Carriers of gene polymorphisms related to stress neurobiology respond differently to environments than noncarriers according to two patterns: attachment research shows inconsistent diathesis-stress between gene polymorphisms and environment, and temperament, stress physiology, and prenatal programming research show clear patterns of differential susceptibility.

SUMMARY

By synthesizing prenatal and postnatal findings, a model of attachment emerges in which individuals more susceptible to environmental influences are carriers of specific genes, whose endophenotypic markers include stress biology and phenotypic markers include temperament. Intervention should, therefore, focus on parenting and stress regulation strategies for these individuals.

Differential associations of maternal behavior to preschool boys' and girls' executive function

Boys are more sensitive to environmental factors like parental behavior, an important predictor of executive function. This study examined whether the interaction between child sex and maternal behavior was associated with children's executive function in a manner consistent with the vulnerability or differential susceptibility model. Participants were 146 36-month-old children and their mothers. Maternal responsiveness and negative reactivity were coded during structured mother-child interactions. Executive function was operationalized as latent self-control and working memory/inhibitory control (WMIC). Structural equation modelling supported a sex by responsiveness interaction for self-control but not WMIC. Consistent with a vulnerability model, less responsiveness was associated with poorer self-control for boys relative to girls. Boys' self-control may be more vulnerable to the negative effect of unresponsive maternal behavior helping explain boys increased risk for externalizing behavior problems.

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.

Individual differences in sensitivity to positive home environment among children "at risk" for attention-deficit/hyperactivity disorder: A review

Although the evidence for the genetic basis of attention-deficit/hyperactivity disorder (ADHD) is strong, environmental factors, such as the quality of parenting or the home environment, may moderate such genetic liability. The plausible negative effect of a low-quality home environment and negative parenting on child outcomes is well-established; however, the positive effect of a high-quality environment and positive parenting remained largely uninvestigated. Due to the presence of genetic, temperamental, or physiological factors, children who were traditionally considered at-risk for ADHD may be more sensitive to aspects of their environment compared to children who are not at such risk. Therefore, they would be more affected by their environmental experience, either for good or bad. Under supportive environmental conditions, such at-risk individuals might actually outperform their non-vulnerable peers, suggesting that these individual factors might be considered susceptibility factors rather than risk factors. Little is known regarding the positive effect of the environment in the ADHD literature, but it has been demonstrated in cognitive functions that are closely associated with ADHD, such as executive functions (EF). We review this literature and examine the extant empirical support for sensitivity to aspects of the home environment and parenting in the case of ADHD and EF. Moreover, we review factors that could help identify the specific aspects of the home environment and parenting that these children might be more susceptible to. Such knowledge could be valuable when designing preventive interventions and identifying those children that are especially sensitive and could benefit from such interventions. Recommendations for future studies are discussed as well.

I Want More! The Role of Child, Family and Maternal Characteristics on Child Dispositional Greed and Sharing Behavior

Abstract

Greed is often regarded as a negative trait that impedes prosocial behavior in adults. Yet, relatively little is known about the development of greed and its effects on children. We examine the effect of dispositional greed on sharing behavior in 4-to-6-year-olds. In addition, we identified potential factors associated with child greed, including child, family, and maternal characteristics. This study with 63 mother–child dyads (Agechild = 5.11, SD = 0.88, 50.8% female) revealed that child greed was associated with less prosocial behavior in an observational sharing task. More specifically, children who were reported as greedier by their mothers shared less than less greedy children. Having fewer siblings, less mindful maternal parenting style, and high maternal trait anxiety was associated with higher dispositional greed in children. Additionally, their mother rated greedier children as having higher negative affectivity. These findings suggest that child greed is an important developmental trait that warrants further investigation.

Highlights

• 63 mother–child dyads revealed that child greed was associated with less pro-social behavior in an observational sharing task

• Child greed was associated with higher rates of child negative affectivity.

• Having fewer siblings, less mindful parenting style, high maternal trait anxiety predicted dispositional greed in 4-to-6-year-old children

Longitudinal Influences of DRD4 Polymorphism and Early Maternal Caregiving on Personality Development and Problem Behavior in Middle Childhood and Adolescence

Most studies examining gene-environment effects on self-regulation focus on outcomes early childhood or adulthood. However, only a few studies investigate longitudinal effects during middle childhood and adolescence and compare two domains of early caregiving. In a longitudinal follow-up with a sample of N = 87, we studied the effects of differences in the DRD4 tandem repeat polymorphisms and two domains of early maternal caregiving quality on children's personality development using Block's California Child Q-Set (CCQ) at age six and age 12 and on problem behavior at ages six and seven. Early maternal regulation quality predicted later ego-resiliency and aggressiveness. In addition, significant gene-environment interactions revealed that children with the 7+ DRD4 tandem repeat polymorphism and poor maternal regulation quality in infancy showed lower scores in ego-resiliency and higher scores in ego-undercontrol and CCQ aggressiveness. In contrast, children who had experienced effective maternal regulation in infancy showed a comparable level in personality traits and problem behavior as the DRD4 7- group independent of the levels of maternal regulatory behavior. Similarly, longitudinal caregiving × DRD4 interactions were found for behavior problems in middle childhood, especially for oppositional-aggression, inattentive-hyperactivity, and social competence. Early caregiving effects were only found for maternal regulation quality, but not for maternal responsiveness. Effective early maternal regulation in infancy can moderate the negative effect of DRD4 7+ on children's self-regulation in middle childhood and adolescence. However, maternal responsiveness has no comparable effects. It seems relevant to consider several dimensions of early caregiving and to also measure the environment in more detail in gene-environment studies.

Early experience unpredictability in child development as a model for understanding the impact of the COVID-19 pandemic: A translational neuroscience perspective

Extensive evidence links adverse experiences during childhood to a wide range of negative consequences in biological, socioemotional, and cognitive development. Unpredictability is a core element underlying most forms of early adversity; it has been a focus of developmental research for many years and has been receiving increasing attention recently. In this article, we propose a conceptual model to describe how unpredictable and adverse early experiences affect children's neurobiological, behavioral, and psychological development in the context of the COVID-19 pandemic. We first highlight the critical role of unpredictability in child development by reviewing existing conceptual models of early adversity as they relate to subsequent development across the lifespan. Then, we employ a translational neuroscience framework to summarize the current animal- and human-based evidence on the neurobiological alterations induced by early experience unpredictability. We further argue that the COVID-19 pandemic serves as a global "natural experiment" that provides rare insight to the investigation of the negative developmental consequences of widespread, clustered, and unpredictable adverse events among children. We discuss how the pandemic helps advance the science of unpredictable early adverse experiences. As unpredictability research continues to grow, we highlight several directions for future studies and implications for policymaking and intervention practices.

Differential Relations of Parental Behavior to Children's Early Executive Function as a Function of Child Genotype: A Systematic Review

Child genotype is an important biologically based indicator of sensitivity to the effects of parental behavior on children's executive function (EF) in early childhood, birth to age 5. While evidence for gene × parental behavior interactions on children's early EF is growing, researchers have called the quality of evidence provided by gene × environment interaction studies into question. For this reason, this review comprehensively examined the literature and evaluated the evidence for gene × parental behavior interactions on children's early EF abilities. Psychology and psychiatry databases were searched for published peer-reviewed studies. A total of 18 studies met inclusion criteria. Twenty-nine of 89 (33%) examined interactions were significant. However, a p-curve analysis did not find the significant interactions to be of evidential value. A high rate of false positives, due to the continued use of candidate gene and haplotype measures of child genotype and small sample sizes, likely contributed to the high rate of significant interactions and low evidential value. The use of contemporary molecular genetic measures and larger sample sizes are necessary to advance our understanding of child genotype as a moderator of parental effects on children's EF during early childhood and the biopsychosocial mechanisms underlying children's EF development during this critical period. Without these changes, future research is likely to be stymied by the same limitations as current research.

ANKK1 and TH gene variants in combination with paternal maltreatment increase susceptibility to both cognitive and attentive impulsivity

Recent scientific findings suggest that dopamine exerts a central role on impulsivity, as well as that aversive life experiences may promote the high levels of impulsivity that often underlie violent behavior. To deepen our understanding of the complex gene by environment interplay on impulsive behavior, we genotyped six dopaminergic allelic variants (ANKK1-rs1800497, TH-rs6356, DRD4-rs1800955, DRD4-exonIII-VNTR, SLC6A3-VNTR and COMT-rs4680) in 655 US White male inmates convicted for violent crimes, whose impulsivity was assessed by BIS-11 (Barratt Impulsiveness Scale). Furthermore, in a subsample of 216 inmates from the whole group, we also explored the potential interplay between the genotyped dopaminergic variants and parental maltreatment measured by MOPS (Measure of Parental Style) in promoting impulsivity. We found a significant interaction among paternal MOPS scores, ANKK1-rs1800497-T allele and TH-rs6356-A allele, which increased the variance of BIS-11 cognitive/attentive scores explained by paternal maltreatment from 1.8 up to 20.5%. No direct association between any of the individual genetic variants and impulsivity was observed. Our data suggest that paternal maltreatment increases the risk of attentive/cognitive impulsivity and that this risk is higher in carriers of specific dopaminergic alleles that potentiate the dopaminergic neurotransmission. These findings add further evidence to the mutual role that genetics and early environmental factors exert in modulating human behavior and highlight the importance of childhood care interventions.

A neural model of vulnerability and resilience to stress-related disorders linked to differential susceptibility

Expert opinion remains divided concerning the impact of putative risk factors on vulnerability to depression and other stress-related disorders. A large body of literature has investigated gene by environment interactions, particularly between the serotonin transporter polymorphism (5-HTTLPR) and negative environments, on the risk for depression. However, fewer studies have simultaneously investigated the outcomes in both negative and positive environments, which could explain some of the inconclusive findings. This is embodied by the concept of differential susceptibility, i.e., the idea that certain common gene polymorphisms, prenatal factors, and traits make some individuals not only disproportionately more susceptible and responsive to negative, vulnerability-promoting environments, but also more sensitive and responsive to positive, resilience-enhancing environmental conditions. Although this concept from the field of developmental psychology is well accepted and supported by behavioral findings, it is striking that its implementation in neuropsychiatric research is limited and that underlying neural mechanisms are virtually unknown. Based on neuroimaging studies that examined how factors mediating differential susceptibility affect brain function, we posit that environmental sensitivity manifests in increased salience network activity, increased salience and default mode network connectivity, and increased salience and central executive network connectivity. These changes in network function may bring about automatic exogenous attention for positive and negative stimuli and flexible attentional set-shifting. We conclude with a call to action; unraveling the neural mechanisms through which differential susceptibility factors mediate vulnerability and resilience may lead us to personalized preventive interventions.

An interaction between early threat exposure and the oxytocin receptor in females: Disorder-specific versus general risk for psychopathology and social-emotional mediators

Early threat exposure is a transdiagnostic risk factor for psychopathology, and evidence suggests that genetic variation in the oxytocin receptor (OXTR) moderates this association. However, it is unclear if this gene-by-environment (G×E) interaction is tied to unique risk for disorder-specific outcomes or instead increases shared risk for general psychopathology. Moreover, little is known about how this G×E interaction increases risk. The current study utilized a prospective, longitudinal sample of females (n = 2,020) to examine: (a) whether the interaction between early threat exposure and OXTR variation (rs53576, rs2254298) confers risk for disorder-specific outcomes (depression, anxiety, borderline and antisocial personality disorders) and/or general psychopathology in early adulthood; and (b) whether social-emotional deficits (emotion dysregulation, callousness, attachment quality) during adolescence constitute mediating mechanisms. Consistent with hypotheses, the interactive effects of early threat exposure and OXTR variation (rs53576) predicted general psychopathology, with threat-exposed women carrying at least one copy of the rs53576 A-allele at greatest risk. This interaction was mediated via emotional dysregulation in adolescence, with threat-exposed A-allele carriers demonstrating greater emotion dysregulation, and greater emotion dysregulation predicting general psychopathology in early adulthood. Findings suggest that this G×E places women at risk for a broad range of psychopathology via effects on emotion dysregulation.

Dopamine-Related Genes Moderate the Association Between Family Environment and Executive Function Following Pediatric Traumatic Brain Injury: An Exploratory Study

OBJECTIVE

This study examined whether carrying dopamine-related "risk" genes-either the dopamine transporter (DAT1) 10-repeat allele or dopamine receptor-4 (DRD4) 7-repeat allele-moderated the association of family environment and executive function (EF) following traumatic brain injury (TBI) in early childhood.

METHODS

Caregivers of children with TBI or orthopedic injury (OI) completed the Behavior Rating Inventory of Executive Function (BRIEF) at postinjury visits. General linear models examined gene by environment interactions as moderators of the effects of TBI on EF at 12 months and 7 years postinjury.

RESULTS

At 12 months, we did not find any significant gene by environment interactions. At 7 years, we found a significant 3-way interaction among combined carrier status, level of permissive parenting, and injury type. For children exposed to more optimal parenting, carriers of DAT1 and/or DRD4 risk alleles with TBI showed significantly worse parent-reported EF than carriers with OI. In those with less optimal parenting, carriers and noncarriers with TBI, as well as carriers with OI, showed significantly worse parent-reported EF than noncarriers with OI, with medium to large effect sizes.

CONCLUSIONS

The findings highlight the importance of considering polygenetic and environmental factors in future studies of recovery following TBI and other injuries in childhood.

Sensitivity, but to which environment? Individual differences in sensitivity to parents and peers show domain-specific patterns and a negative genetic correlation

The idea that individuals differ in their sensitivity to the environment's effects is a cornerstone of developmental science. It has been demonstrated repeatedly, for different kinds of stressors, outcomes, and sensitivity markers. However, almost no empirical work was done to examine whether environmental sensitivity is domain-general (i.e., the same individuals are sensitive to different environmental contexts) or domain-specific (i.e., different individuals are sensitive to different environmental contexts), despite its importance to understanding human development, learning, and behavior. To address this question, phenotypic sensitivity to parents and to peers were compared in 1313 11-year-old Israeli adolescent twins. We found that, (1) our phenotypic markers indeed moderate environmental influences, with a discriminant predictive utility, (2) adolescents who are sensitive to their parents are not necessarily sensitive to their peers, and (3) sensitivity to parents and sensitivity to peers have different etiologies and show a negative genetic correlation, indicating that adolescents carrying genetic markers for sensitivity to parents are less likely to carry genetic markers for sensitivity to peers. These findings suggest that environmental sensitivity shows domain-specific patterns, as different individuals can be sensitive to different environments. We discuss the theoretical, empirical, and practical implications of domain-specificity of environmental sensitivity.

The gray matter volume of the temporoparietal junction varies across cultures: a moderating role of the dopamine D4 receptor gene (DRD4)

Prior work shows that compared to European Americans, East Asians show an enhanced propensity to take the perspective of another person. In the current work, we tested whether this cultural difference might be reflected in the gray matter (GM) volume of the temporoparietal junction (TPJ), a brain region selectively implicated in perspective taking and mentalizing. We also explored whether the cultural difference in the TPJ GM volume might be moderated by dopamine D4 receptor gene (DRD4) exon 3 variable-number tandem repeat polymorphism. Structural magnetic resonance imaging of 66 European Americans and 66 East Asian-born Asians were subjected to voxel-based morphometry. It was observed that the GM volume of the right TPJ was greater among East Asians than among European Americans. Moreover, this cultural difference was significantly more pronounced among carriers of the 7- or 2-repeat allele of DRD4 than among the non-carriers of these alleles. Our findings contribute to the growing evidence that culture can shape the brain.

Reckless Generosity, Parkinson's Disease and Dopamine: A Case Series and Literature Review

BACKGROUND

Impulse control disorders (ICDs) are a frequent side effect of dopamine replacement therapy (DRT) in Parkinson's disease (PD). Reckless generosity might expand the spectrum of known ICDs.

CASES

Over 18 months, we encountered three PD patients exhibiting reckless generosity under DRT, leading to disastrous financial and social consequences.

LITERATURE REVIEW

Except for another case series describing reckless generosity in three PD patients, only one study has examined generosity in PD patients; with findings suggesting that PD patients with ICDs are less sensitive to the aversive aspects of the lack of reciprocation in social settings. Studies with healthy individuals suggest that increased availability of dopamine might reduce social discounting and promote egalitarian behavior, and thereby increase generous behavior towards strangers. Genetic studies show that polymorphisms in dopamine D4 receptors influence generous behavior.

CONCLUSIONS

Reckless generosity in PD patients with DRT might be underreported and should therefore be carefully be screened for by clinicians. A potential mechanism underlying this ICD-related behavior might be a sensitization of the mesolimbic and mesocortical dopaminergic system, leading to reduced social discounting and maladaptive reward-learning. Further research is needed to investigate the prevalence and underlying mechanisms of reckless generosity in PD patients.

Planned missing data in early literacy interventions: A replication study with an additional gold standard

INTRODUCTION

In a digital early literacy intervention RCT, children born late preterm fell behind peers when in a control condition, but outperformed them when assigned to the intervention. Results did however not replicate previous findings. Replication is often complicated by resource quality. Gold Standard measures are generally time-intensive and costly, while they closely align with, and are more sensitive to changes in, early literacy and language performance. A planned missing data approach, leaving these gold standard measures incomplete, might aid in addressing the origin(s) of non-replication.

METHODS

Participants after consent were 695 p Dutch primary school pupils of normal and late preterm birth. The high-quality measures, in additional to simpler but complete measures, were intentionally administered to a random subsample of children. Five definitions of gold standard alignment were evaluated.

RESULTS

Two out of five gold standard levels improved precision compared to the original results. The lowest gold standard level did not lead to improvement: precision was actually diminished. In two gold standard definitions, an alphabetical factor and a writing-only factor the model estimates were comparable to the original results. Only the most precise definition of the gold standard level replicated the original results.

CONCLUSION

Gold standard measures could only be used to improve model efficiency in RCT-designs under sufficiently high convergent validity.

Life-course effects of early life adversity exposure on eating behavior and metabolism

Environmental variations in early life influence brain development, making individuals more vulnerable to psychiatric and metabolic disorders. Early life stress (ELS) has a strong impact on the development of eating behavior. However, eating is a complex behavior, determined by an interaction between signals of energy homeostasis, neuronal circuits involved in its regulation, and circuits related to rewarding properties of the food. Although mechanisms underlying ELS-induced altered feeding behavior are not completely understood, evidence suggest that the effects of ELS on metabolic, mood, and emotional disorders, as well as reward system dysfunctions can contribute directly or indirectly to altered feeding behavior. The focus of this chapter is to discuss the effects of ELS on eating behavior and metabolism, considering different factors that control appetite such as energy homeostasis, hedonic properties of the food, emotional and cognitive status. After highlighting classic studies on the association between ELS and eating behavior alterations, we discuss how exposure to adversity can interact with genetics characteristics to predict variable outcomes.

Adverse Childhood Experience, Genes, and PTSD Risk in Soldiers: A Methylation Study

INTRODUCTION

Epigenetics can serve as a marker of susceptibility to many known psychiatric diseases. DNA methylation patterns of multiple genes have been studied in both civilian populations and military personnel with post-traumatic stress disorder (PTSD). Many of these genes serve various functions that span the hypothalamic-pituitary-adrenal axis, immune system, and central nervous system (CNS) growth factors and neurotransmission. It is thought that the methylation levels of such genes may be able to identify individuals who are at higher risk of developing PTSD. Our study seeks to establish whether previously reported PTSD genes possess a particular methylation pattern that is predictive of PTSD in active duty military members with combat exposure.

MATERIALS AND METHODS

This is an institutional review board (IRB)-approved, cross-sectional, case control, gene-environment interaction study. About 170 active military members with and without PTSD were recruited. Patients with a history of structural brain damage, traumatic brain injury (TBI) resulting in loss of consciousness, predeployment diagnosis of PTSD or anxiety disorder, and predeployment prescription of an antidepressant or psychoactive medication were excluded. Validated measures of childhood trauma and adversity (adverse childhood experience [ACE] score), PTSD symptoms (PTSD check-list military version [PCL-M]), and combat exposure scales (CES) were measured via validated questionnaires for all subjects. After extracting DNA from peripheral blood provided by the 170 subjects, we determined methylation percentages, via pyrosequencing assays, for nine target areas within the following seven genes: BDNF, NR3C1, MAN2C1, TLR8, SLC6A4, IL-18, and SKA2. These genes are commonly reported in the literature as being highly correlated with PTSD and early-life traumatic experiences.Methylation levels were measured as a percentage at specific sites within the previously mentioned genes. Data were examined with SPSS v 22.0 Statistics and JMP v13.1 software using a general linear model for methylation × trauma (CES scores) split by diagnosis of PTSD or not, methylation versus childhood trauma (ACE scores), and methylation versus PTSD severity (PCL-M score). Two-way ANOVA was performed to control for antidepressant use. A two-tailed Student t-test was performed for PTSD analyses and was correlated with PTSD diagnosis, demographic information as well as ACE score, PCL-M score, and CES scores.

RESULTS

Differentially methylated sites that were highly associated with PTSD diagnosis were found in three of seven candidate genes: BDNF, NR3C1, and MAN2C1. When compared to controls, patients with PTSD diagnosis had significantly lower levels of methylation, even after controlling for antidepressant use. PCL-M, ACE, and CES scores were significantly associated with PTSD diagnosis.

CONCLUSION

Our study suggests that methylation of key genes involved in synaptic plasticity and the hypothalamic-pituitary-adrenal axis is associated with lower levels of methylation in military PTSD subjects exposed to combat when compared to their non-PTSD counterparts. Strengths of this study include controlling for antidepressant use and excluding TBI patients. Similar studies in an active duty population of this size are scarce. What is not clear is whether methylation changes are driving PTSD symptomology or whether they are merely a marker of disease. Future areas of research include prospective studies that measure methylation pre- and postcombat exposure in the same individual.

Catechol-O-Methyltransferase Gene Val158Met Polymorphism Moderates the Effect of Social Exclusion and Inclusion on Aggression in Men: Findings From a Mixed Experimental Design

Accumulating research has identified the interactive effects of catechol-O-methyltransferase (COMT) gene Val158Met polymorphism and environmental factors on aggression. However, available evidence was mainly based upon correlational design, which yields mixed findings concerning who (Val vs. Met carriers) are more affected by environmental conditions and has been challenged for the low power of analyses on gene–environment interaction. Drawing on a mixed design, we scrutinized how COMT Val158Met polymorphism (between-group variable) impacts on aggression, assessed by hostility, aggressive motivation, and aggressive behavior, under different social conditions (exclusion vs. inclusion, within-group variable) in a sample of 70 Chinese male undergraduate students. We found that both Val/Val homozygote and Met alleles carriers showed differences in the feelings of hostility and aggressive motivation under conditions of exclusion versus inclusion, but these differences were more pronounced for Met allele carriers. These findings implied that COMT Val158Met polymorphism did not respond to environmental stimuli in an all-or-none way and shed light on the importance of examining the gene–environment interaction using a mixed design.

The etiology of maternal postpartum depressive symptoms: Childhood emotional maltreatment, couple relationship satisfaction, and genes

There is a call for integrative studies examining the roles of biological and psychosocial factors and their interrelations in shaping maternal postpartum psychopathology. Using longitudinal data from 198 primiparous mothers, we tested a biopsychosocial model for the etiology of maternal postpartum depressive symptoms that integrated childhood emotional maltreatment, couple relationship satisfaction, and oxytocin and dopamine D4 receptor genes (i.e., OXTR rs53576 and DRD4). Results indicate (a) two indirect effects from childhood emotional maltreatment and DRD4 to depressive symptoms at 1 year postpartum through couple relationship satisfaction at 6 months postpartum; (b) an interactive effect between DRD4 and couple relationship satisfaction at 6 months postpartum in predicting depressive symptoms at 1 year postpartum, which is in concert with the differential susceptibility hypotheses; and (c) no mediating effects or moderating effects (after adjusting for multiple testing with Bonferroni correction) involving OXTR rs53576. Notably, all associations were identified after controlling for several key covariates (e.g., maternal prenatal depressive symptoms). Last, robustness of the currently identified interactive effect involving DRD4 was demonstrated by an extensive set of additional analyses considering the effects of rGE, G × Covariates, and/or E × Covariates. Taken altogether, this study represents one of the initial efforts for a more sophisticated portrayal of how nature and nurture forces may work in conjunction with each other to shape new mothers' psychopathology. Yet given the current modest sample size and candidate gene approach, our findings are preliminary, should be cautiously interpreted, and need to be replicated with more rigorous designs. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Early childhood psychosocial family risks and cumulative dopaminergic sensitizing score: Links to behavior problems in U.S. 9-year-olds

BACKGROUND

We examined, (a) whether in early childhood exposure to risky family environment in different domains (socioeconomic, mental, parenting practices, health behavior, and child-related risks) and accumulatively across various domains (cumulative risk) is associated with child's problem behavior at age 9, and (b) whether the association is more pronounced in children carrying cumulative dopaminergic sensitizing genotype or living in low-income families.

METHODS

Participants were 2,860 9-year old children (48% females; 48% Black) and their mothers from the 'Fragile Families and Child Wellbeing Study', a probability birth cohort from large U.S. cities. Mothers responded to questions on child's problem behavior (CBCL). Children responded to questions about their vandalism and substance use.

RESULTS

Cumulative family risk was associated with higher internalizing and externalizing behavior and higher vandalism and substance use. All domain-specific risk clusters were associated with higher internalizing behavior and, with the exception of child-related risk, with higher externalizing behavior. Mental health risks, risky parenting practices, and risky health behavior were associated with higher vandalism. Risky parenting practices were associated with higher substance use. The associations were robust to adjustment for cumulative dopaminergic sensitizing genotype. No G x E interactions with dopaminergic genotype and family SES were observed.

LIMITATIONS

Sample size was relatively small for genetic analysis and polygenic risk scores were not available.

CONCLUSIONS

Exposure to cumulative psychosocial family risks from early childhood is associated with early indicators of problem behavior in adolescence.

Examining the Effects of Media-Generated Stereotypes on Receivers’ Trust and Attitude in Pakistan. Moderating Influence of Ethnicity and Gender

There is a long-standing debate about the effects of media-generated stereotypes on receivers’ trust and attitude. However, there is insufficient consensus about their influence on the media receiver’s ecological perspective in determining their extent of trust and attitudes. Drawing an analogy from Differential Susceptibility to Media Effect Model (hereafter DSMM) notion that media effects are conditional and are contingent on differential-susceptibility, this study examines the influence of dispositional and social susceptibility to media. To do so, the study validates the influence of media user’s gender (dispositional susceptibility) and ethnicity (social susceptibility) in determining the outcomes of media-generated stereotypes, media trust (MT), and attitude towards media organization (AO). The survey method has been employed to collect data through a self-administered questionnaire from 1061 university students in public sector institutions in Pakistan. The results provide empirical evidence that media-generated stereotypes are a substantially negative predictor of media trust and attitudes towards the media organization. The results also validate that the influence of the stereotyping manifested by the receiver’s ecological perspective such as ethnicity and gender are crucial determinants of the receiver’s trust and attitudes. Managerially, the study urges that journalistic practices must be more ethnoculturally inclusive, to cope with the contemporary media landscape.

Comportamento Altruísta na Infância: O que a Literatura nos Mostra

Resumo Uma variedade de comportamentos altruístas diferenciados tem sido evidenciada na infância. O presente artigo objetivou sistematizar estudos empíricos produzidos nos anos de 2010 a 2015 sobre o altruísmo infantil. Após a elaboração e aplicação de um protocolo sistematizado de seleção, foram encontrados 14 artigos, os quais foram analisados na íntegra. Os estudos contemplaram o altruísmo infantil (1 a 11 anos de idade) em associação a diferentes variáveis, tais como avaliação moral, custos de resposta, renda familiar, distância social, capacidade de abster-se de prêmios imediatos, eventos adversos, representações de apego, dominância social, composição genética, entre outras. Concluiu-se que crianças ainda muito jovens em contextos variados demonstram altruísmo por meio de ações topograficamente diversas à medida que encontram oportunidades para isso.

Neonatal hippocampal volume moderates the effects of early postnatal enrichment on cognitive development

Environmental enrichment, particularly during the early life phases of enhanced neuroplasticity, can stimulate cognitive development. However, individuals exhibit considerable variation in their response to environmental enrichment. Recent evidence suggests that certain neurophenotypes such as hippocampal size may index inter-individual differences in sensitivity to environmental conditions. We conducted a prospective, longitudinal investigation in a cohort of 75 mother-child dyads to investigate whether neonatal hippocampal volume moderates the effects of the postnatal environment on cognitive development. Newborn hippocampal volume was quantified shortly after birth (26.2 ± 12.5 days) by structural MRI. Measures of infant environmental enrichment (assessed by the IT-HOME) and cognitive state (assessed by the Bayley-III) were obtained at 6 months of age (6.09 ± 1.43 months). The interaction between neonatal hippocampal volume and enrichment predicted infant cognitive development (b = 0.01, 95 % CI [0.00, 0.02], t = 2.08, p = .04), suggesting that exposure to a stimulating environment had a larger beneficial effect on cognitive outcomes among infants with a larger hippocampus as neonates. Our findings suggest that the effects of the postnatal environment on infant cognitive development are conditioned, in part, upon characteristics of the newborn brain, and that newborn hippocampal volume is a candidate neurophenotype in this context.

Dopamine Functioning and Child Externalizing Behavior: A Longitudinal Analysis of Polygenic Susceptibility to Parenting

OBJECTIVE

This study investigated how genetic susceptibility may affect children's sensitivity to parenting practices in their development of externalizing behavior. We created a continuous polygenic index composed of 5 dopamine polymorphisms to investigate the moderating role of dopamine-related genes in shaping parent-child gene-by-environment (Gc×E) interactions. Accumulating research supports that differences in children's dopamine neurotransmission make certain children more susceptible to both negative and positive parenting practices, a "for-better and for-worse" effect.

METHODS

Data from a 3-wave longitudinal study (4 months between waves) on 190 at-risk families with children aged 4 to 8 were used to investigate whether a heightened polygenic index score amplified the associations between negative and positive parenting and later children's externalizing behavior. Parenting practices and child externalizing behavior were assessed by parent-reported questionnaires.

RESULTS

Findings were not in line with the expectation that there was a stronger association between positive and negative parenting and later externalizing behavior for children with higher scores on the polygenic susceptibility index. Rather, children with a lower score on the polygenic susceptibility index showed more later externalizing behavior in response to positive parenting behavior, whereas for children with a higher score on the polygenic index, positive parenting was predictive of relatively lower levels of later child externalizing behavior.

CONCLUSION

The results indicate that not only are children with higher but also lower scores on the polygenic index sensitive to parenting, they suggest that different phenotypical characteristics related to reward processing might underlie these genetic susceptibilities to parenting practices.

Socioemotional Mechanisms of Children's Differential Response to the Effects of Maternal Sensitivity on Child Adjustment

OBJECTIVE

Children differ in the extent to which they reap the benefits of maternal sensitive care or suffer the adverse consequences of insensitive care, and these differences can be accounted for by biological characteristics. However, how susceptible children adapt to maternal sensitivity in ways that either maximize positive development or lead to maladjustment has yet to be determined. Here, we propose a novel model of socioemotional mechanisms by which the joint influences of maternal sensitivity and child biological characteristics influence child adjustment.

DESIGN

We propose a theoretical model, in which children's vagal functioning and polymorphisms in serotonin transporter (5-HTTLPR) and dopamine receptor D4 (DRD4) genes confer susceptibility to the effects of maternal sensitivity on internalizing, externalizing, prosocial and moral behavior via changes in interpersonal strategies for emotion regulation, the threat response system, and empathy.

RESULTS

Theoretical and empirical support for the proposed mechanisms are provided.

CONCLUSIONS

The proposed mechanistic model of susceptibility to maternal sensitivity offers a novel framework of for whom and how children are affected by early maternal care, highlighting multiple reciprocal, interacting influences across genes, physiology, behavior, and the environment.

When mummy and daddy get under your skin: A new look at how parenting affects children's DNA methylation, stress reactivity, and disruptive behavior

Child maltreatment is a global phenomenon that affects the lives of millions of children. Worldwide, as many as one in three to six children encounter physical, sexual, or emotional abuse from their caregivers. Children who experience abuse often show alterations in stress reactivity. Although this alteration may reflect a physiological survival response, it can nevertheless be harmful in the long run-increasing children's disruptive behavior and jeopardizing their development in multiple domains. But can we undo this process in at-risk children? Based on several lines of pioneering research, we hypothesize that we indeed can. Specifically, we hypothesize that highly dysfunctional parenting leads to an epigenetic pattern in children's glucocorticoid genes that contributes to stress dysregulation and disruptive behavior. However, we also hypothesize that it is possible to "flip the methylation switch" by improving parenting with known-effective parenting interventions in at-risk families. We predict that improved parenting will change methylation in genes in the glucocorticoid pathway, leading to improved stress reactivity and decreased disruptive behavior in children. Future research testing this theory may transform developmental and intervention science, demonstrating how parents can get under their children's skins-and how this mechanism can be reversed.

The ego dampening influence of religion: evidence from behavioral genetics and psychology

Religion is a product of evolutionary and biological processes. Thus, understanding why some people are religious and how it impacts their everyday lives requires an integrated perspective. This review presents a theoretical framework incorporating recent findings on religious influences on the behavioral expression of genetic and psychological predispositions. We propose that religion may facilitate ego dampening, or weakening of the impact of one's internal drive, for the service of sociality. Evidence from gene-environment interaction and behavioral studies suggests that religious beliefs and practices may dampen more prepotent, self-focused motives that can be at odds with cooperation and social cohesion. The review underscores the importance of taking an interdisciplinary perspective to understand complex and fundamental questions about religion.

Three phases of Gene × Environment interaction research: Theoretical assumptions underlying gene selection

Some Gene × Environment interaction (G×E) research has focused upon single candidate genes, whereas other related work has targeted multiple genes (e.g., polygenic scores). Each approach has informed efforts to identify individuals who are either especially vulnerable to the negative effects of contextual adversity (diathesis stress) or especially susceptible to both positive and negative contextual conditions (differential susceptibility). A critical step in all such molecular G×E research is the selection of genetic variants thought to moderate environmental influences, a subject that has not received a great deal of attention in critiques of G×E research (beyond the observation of small effects of individual genes). Here we conceptually distinguish three phases of G×E work based on the selection of genes presumed to moderate environmental effects and the theoretical basis of such decisions: (a) single candidate genes, (b) composited (multiple) candidate genes, and (c) GWAS-derived polygenic scores. This illustrative, not exhaustive, review makes it clear that implicit or explicit theoretical assumptions inform gene selection in ways that have not been clearly articulated or fully appreciated.

ADHD symptoms across adolescence: the role of the family and school climate and the DRD4 and 5-HTTLPR genotype

We examined bidirectional relations between attention-deficit/hyperactivity disorder (ADHD) symptoms and family and school climate, and the possible role of DRD4 and/or 5-HTTLPR genotypes herein. Three-wave longitudinal data of 1860 adolescents (mean ages 11, 13.5, and 16 years) from the general population and clinic-referred cohort of TRacking Adolescents' Individual Lives Survey were used. Using a multigroup Random Intercept Cross-Lagged Panel Model, we tested between-person (i.e., stable trait levels) and within-person (i.e., causal processes) associations across ADHD symptoms, family and school climate, and the extent to which these depended on genotype. Findings indicated no influence of genotype. Results did show significant between-person differences (ADHD symptoms with family climate r = .38; and school climate r = .23, p values < .001), indicating that higher stable levels of ADHD symptoms were associated with a less favorable family and school climate. Regarding within-person causal processes, ADHD symptoms predicted a less favorable family climate in early adolescence (β = .16, p < .01), while ADHD symptoms predicted a more favorable family climate in the later phase of adolescence (β = - .11, p < .01), a finding which we explain by normative developmental changes during adolescence. Overall, this study showed that negative associations between ADHD symptoms and both family and school climate are largely explained by stable between-person differences. We recommend applying the Random Intercept Cross-Lagged Path Model to developmental data to tease stable associations and change processes apart.

DRD4 polymorphisms modulate reward positivity and P3a in a gambling task: Exploring a genetic basis for cultural learning

Prior work shows that people respond more plastically to environmental influences, including cultural influences, if they carry the 7 or 2-repeat (7/2R) allelic variant of the dopamine D4 receptor gene (DRD4). The 7/2R carriers are thus more likely to endorse the norms and values of their culture. So far, however, mechanisms underlying this moderation of cultural acquisition by DRD4 are unclear. To address this gap in knowledge, we tested the hypothesis that DRD4 modulates the processing of reward cues existing in the environment. About 72 young adults, preselected for their DRD4 status, performed a gambling task, while the electroencephalogram was recorded. Principal components of event-related potentials aligned to the Reward-Positivity (associated with bottom-up processing of reward prediction errors) and frontal-P3 (associated with top-down attention) were both significantly more positive following gains than following losses. As predicted, the gain-loss differences were significantly larger for 7/2R carriers than for noncarriers. Also, as predicted, the cultural backgrounds of the participants (East Asian vs. European American) did not moderate the effects of DRD4. Our findings suggest that the 7/2R variant of DRD4 enhances (a) the detection of reward prediction errors and (b) controlled attention that updates the context for the reward, thereby suggesting one possible mechanism underlying the DRD4 × Culture interactions.