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Externalizing behavior is substantially affected by genetic effects, which are moderated by environmental exposures. However, little is known about whether these moderation effects differ depending on individual characteristics, and whether moderation of environmental effects generalizes across different environmental domains. With a large sample (N = 1,441 individuals) of early adolescent twins (ages 11 and 13), using a longitudinal multi-informant design, we tested interaction effects between negative emotionality and both positive and negative aspects of three key social domains: parents, peers, and schools, on the phenotypic variance as well as the etiology of externalizing. Negative emotionality moderated some of the environmental effects on the phenotypic, genetic, and environmental variance in externalizing, with adolescents at both ends of the negative emotionality distribution showing different patterns of sensitivity to the tested environmental influences. This is the first use of gene-environment interaction twin models to test individual differences in environmental sensitivity, offering a new approach to study such effects.

Twin relationships have a significant effect on the twins’ life and their families. In the first comprehensive study of this topic, our purpose was to examine the developmental courses of four dyadic dimensions of twins’ relationships: closeness, dependence, conflict and rivalry, and the impact of zygosity and parenting on their relationships. Parents reported on their twins’ relationships ( N = 1547 mothers and 536 fathers with data from at least one of four measurement points from 3 to 8–9 years of age). The sample included 322 monozygotic twin dyads (sharing virtually 100% of their genes), and 1194 dizygotic twin dyads (sharing 50% of their genetic variance, on average). Our findings indicated that closeness and dependence decreased while rivalry increased through childhood. Dependence and rivalry also presented quadratic change. The twins’ conflict increased only for dizygotic twins. As expected, we found that the twins’ closeness and dependence were highly associated, as did the associations between conflict and rivalry. The mostly nonsignificant associations of closeness with conflict and rivalry reinforced the notion that they are not bi-polar opposites. However, dependence was positively related to the twins’ conflict and rivalry. A zygosity effect was also evident as monozygotic twins had higher levels of closeness and dependence than dizygotic twins through childhood, but there was no significant difference in the levels of their conflict and rivalry. In congruence with family system theories, parental positivity predicted the twins’ closeness and dependence, and parental negativity predicted the twins’ dependence, conflict and rivalry. The results were discussed in light of an evolutionary perspective and the twins’ developmental challenges through childhood.

Children's negative emotionality (NE) is frequently associated with parental negativity, but causal understanding of this relationship is limited. In addition, little is known about how genetic and environmental factors affect this relationship during middle childhood. We addressed these gaps by applying a quantitative genetic analysis to cross-lagged associations between mothers' and fathers' parental negativity and children's NE during middle childhood. The sample comprised of 456 families when the children were 6.5 years old, and 401 families when the children were 8/9 years old. Mothers' and fathers' negativity and children's NE were assessed using questionnaires. Results showed that variation in parental negativity was mainly accounted for by the environment shared by children, with some indication of an evocative effect of the children's genes on mothers, but not fathers. Children's NE was accounted for by both genetic and shared environmental influences. Parental negativity and children's NE had moderate continuity over the course of two years. Mothers' (but not fathers') negativity when the children were 6.5 years old predicted change in children's NE (rated by the same or the other parent) toward age 8/9 years, but not the other way around. Shared environmental influences were the main contributor to the association between earlier mothers' negativity and later children's NE. Thus, although children's NE was partially heritable, and parenting too was partially accounted for by children's genes, the association between parental negativity and children's NE, at this age, reflects environmental effects and is compatible with mothers' influence on children. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

The Longitudinal Israeli Study of Twins (LIST) focuses on the developmental, genetic and environmental contributions to individual differences in children’s and adolescents’ social behavior. Key variables have been empathy, prosocial behavior, temperament and values. Another major goal of LIST has been to study gene–environment correlations, mainly concerning parenting. LIST includes 1657 families of Hebrew-speaking Israeli twins who have participated at least once in the study. Children’s environment and their development are assessed in a multivariate, multimethod fashion, including observed, parent-reported and self-reported data. The current article summarizes and updates recent findings from LIST. For example, LIST provided evidence for the heritability of human values with the youngest sample to date, and the first genetic investigation of adolescents’ identity formation. Finally, future aims of LIST are discussed.

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.

Objective Infants' sleeping patterns can influence parents' sleep and their well-being. Infants' sleeping problems can evoke negative emotions from their parents because of the influence the problems have on parents' lives. However, little is known regarding the associations between infants' night sleep patterns and parents' overall negativity toward their children. The objective of this study was to study this association. Methods In a longitudinal design, we followed infants and their parents from 9 to 18 months. Overall, 392 families participated in the study. Parents' negativity and children's sleeping patterns were assessed with questionnaires. Results Parents' negativity and children's sleeping problems showed moderate continuity through the study's 9-month period. Children's sleeping problems at 9 months predicted an increase in mothers' (but not fathers') negativity at 18 months. Parents' negativity was not associated with infants' sleep problems. Conclusion The results of this study suggest that already in infancy, children's tendencies, in this case sleep, can evoke negative emotions in their mothers and highlight infants' roles in the intricate parent-child relationship.

Unraveling factors that influence parenting is of great importance, since parents play an important role in their children's development. In this study we focused on parental prenatal expectations, parents' gender and child's distress to limitations as possible influences on parental behavior and observed the longitudinal associations between mothers' and fathers' parenting and their children's distress to limitations. The first wave of the study took place during early pregnancy, while the second and third waves took place when the children were 9 and 18 months old, respectively. Children's distress to limitations was assessed using observations and parental behavior was assessed using questionnaires. All parental variables showed moderate continuity from pregnancy until the child was 18 months, while children's distress did not. Children's distress when they were 9 months predicted an increase in both parents' negativity at 18 months, while fathers' control at 9 months predicted a decrease in children's distress from 9 to 18 months. The results shed light on the intricate parent-child relationship and emphasize children's role in the parenting they receive, as well as differences between mothers and fathers and their associations with children's distress to limitations. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Human values are abstract goals, affecting decisions, choices and behavior (Schwartz, 1992). Despite much value research, there is a lack of research on the etiology of values, specifically potential genetic influences. We therefore reviewed all published twin studies on human values, classified as representing four higher order values across two bipolar dimensions: Self-transcendence versus Self-enhancement and Openness to change versus Conservation. Across most studies, and most values, monozygotic twins correlated more strongly than dizygotic twins, indicating genetic contribution to values. Significant heritability estimates ranged from 24.5 to 85.7%. The effects of the environment shared by family members were generally weaker. Finally, there was a contribution of the non-shared environment for all values. After discussing the implications for the neuropsychological research on values, we suggest several future research directions, which may help guide the future science of the etiology of values. We also discuss the possible discrepancy between our findings and theory and research on value socialization and discuss the interplay of genes and the environment in the development of values.

Empathy is considered a cornerstone of human social experience, and as such has been widely investigated from psychological and neuroscientific approaches. To better understand the factors influencing individual differences in empathy, we reviewed and meta-analyzed the behavioral genetic literature of emotional empathy- sharing others’ emotions (k=13), and cognitive empathy- understanding others’ emotions (k = 15), as manifested in twin studies. Results showed that emotional empathy is more heritable, 48.3 % [41.3 %–50.6 %], than cognitive empathy, 26.9 % [18.1 %–35.8 %]. Moreover, cognitive empathy as examined by performance tests was affected by the environment shared by family members, 11.9 % [2.6 %–21.0 %], suggesting that emotional understanding is influenced, to some degree, by environmental factors that have similar effects on family members beyond their genetic relatedness. The effects of participants’ age and the method used to asses empathy on the etiology of empathy were also examined. These findings have implications for understanding how individual differences in empathy are formed. After discussing these implications, we suggest theoretical and methodological future research directions that could potentially elucidate the relations between genes, brain, and empathy.

Delayed gratification is the ability to postpone an immediate gain in favor of greater and later reward. Although delayed gratification has been studied extensively, little is known about the motivation behind children's decisions. Since values are cognitive representations of individuals' motivations, which serve to guide behavior, we studied the relationship between children's values and delayed gratification. Two main distinct motivations overlapping with values may underlie this decision: conservation - the desire to reduce uncertainty and preserve the status quo, and self-enhancement - the desire to maximize resources and profit for the self. Accordingly, we hypothesized that conservation values would relate to children's preference to hold on to what is given as soon as possible, and that self-enhancement values would relate to children's preference for delaying gratification. Seven-year old children (N = 205) ranked their values with the Picture-Based Values Survey (Doring et al., 2010) as part of the Longitudinal Israeli Study of Twins (LIST) (Avinun and Knafo, 2013). The children also played a decision-making animation game that included delayed gratification decisions. In support of our hypotheses, greater delayed gratification related negatively to conservation values, specifically to security and tradition, and related positively to self-enhancement values, especially power and achievement. This is one of the first demonstrations that children's values relate meaningfully to their behaviors.

Background Genomic analysis of the child might offer new potential to illuminate human parenting. We examined whether offspring (G2) genome-wide genotype variation (SNPs) is associated with their mother's (G1) emotional warmth and intolerance, indicating a gene-environment correlation. If this association is stronger than between G2 ' s genes and their emotional warmth and intolerance toward their own children, then this would indicate the presence of an evocative gene-environment correlation. To further understand how G1 mother's parenting has been evoked by genetically influenced characteristics of the child (G2), we examined whether child (G2) temperament partially accounted for the association between offspring genes and parental responses. Methods Participants were from the Young Finns Study. G1 mothers (N = 2,349; mean age 39 years) self-reported the emotional warmth and intolerance toward G2 in 1980 when the participants were from 3 to 18 years old. G2 participants answered the same parenting scales in 2007/2012 (N = 1,378; mean age = 38 years in 2007; 59% female) when their children were on average 11 years old. Offspring temperament traits were self-reported in 1992 (G2 age range 15-30 years). Estimation of the phenotypic variance explained by the SNPs of G2 was done by genome-wide complex trait analysis with restricted maximum likelihood (GCTA-GREML). Results Results showed that the SNPs of a child (G2) explained 22.6% of the phenotypic variance of maternal intolerance (G1; p-value = .039). G2 temperament trait negative emotionality explained only 2.4% points of this association. G2 genes did not explain G1 emotional warmth or G2 ' s own emotional warmth and intolerance. However, further analyses of a combined measure of both G1 parenting scales found genetic effects. Parent or child gender did not moderate the observed associations. Conclusions Presented genome-wide evidence is pointing to the important role a child plays in affecting and shaping his/her family environment, though the underlying mechanisms remain unclear.

Identity formation is a key developmental task in adolescence. Although many adolescents in modern societies face issues of identity, there are substantial individual differences in identity exploration and commitment. Little is known about the origins of these individual differences. The current study investigated the genetic and environmental contributions to identity formation. In total, 571 11-year-old twins (85 monozygotic complete pairs and 176 dizygotic complete pairs) reported on their identity formation, using the Dimensions of Identity Development Scale (DIDS; Luyckx, Schwartz, Berzonsky, et al., 2008), as part of the Longitudinal Israeli Study of Twins (LIST; Avinun & Knafo, 2013). Multidimensional scaling analysis and confirmatory factor analysis supported the presence of all 5 dimensions at this young age: commitment making, exploration in-breadth, ruminative exploration, identification with commitment, and exploration in-depth. However, a model where exploration in-depth was divided into two subscales had a better fit to the data. Monozygotic twins were more similar to each other than dizygotic twins on all dimensions, except for one of the exploration in-depth subscales, supporting the idea that individual differences in various dimensions of identity formation are at least partially influenced by genetics (18-45%). For these dimensions, the rest of the variance was explained by nonshared environment effects (55-82%). Only one of the exploration in-depth subscales, that is, the tendency to explore commitments through discussion with others, showed evidence for the influence of the environment shared by twins (21%) but no genetic effect. Implications of the findings regarding the role of genetics and environment to identity formation are discussed. (PsycINFO Database Record

As they inhabit complex social worlds, adolescents often learn competing values, resulting in value-differentiation, within-individual variability in value importance across contexts. But what are the implications of value-differentiation across age groups and cultures? A study of 4007 adolescents aged 11 to 18 (M = 14.41, SD = 2.16), of three Israeli groups (majority, former Soviet Union immigrants, Arabs) discovered negative relations between value-differentiation and self-esteem, suggesting that confusion may result from value incoherence. The relations were stronger among younger adolescents than older ones and were especially strong among younger first-generation immigrant adolescents, pointing to the need to address the value-differentiation of immigrant adolescents.

Externalizing problems are among the most common mental health problems of children. Research suggests that these problems are heritable, yet little is known about the specific genes involved in their pathophysiology. The current study examined a genotype-endophenotype-phenotype model of externalizing problems in 320 preschool-aged children. Markers of the oxytocin (OXT) and arginine vasopressin (AVP) hormone genes were selected as candidates owing to their known association with psychopathology in other domains. We tested whether OXT and AVP variants were related to children's externalizing problems, as well as two cognitive endophenotypes presumed to underlie these problems: theory of mind (ToM) and executive functioning (EF). Externalizing problems were assessed at age 4.5 using a previously-validated rating scale. ToM and EF were measured with age-appropriate tasks. Using a family-based association design and controlling for non-genomic confounds, support was found for an association between a two-marker OXT haplotype (rs2740210-rs2770378) and a two-marker AVP haplotype (rs1887854-rs3761249) and externalizing problems. Specific associations of these haplotypes with ToM and EF were also observed. Further, ToM and EF were shown to independently and jointly predict externalizing problems, and to partially mediate the effects of OXT and AVP on externalizing problems. This study provides the first evidence that genetic variation in OXT and AVP may contribute to individual differences in childhood externalizing problems, and that these effects may operate through emerging neurocognitive abilities in the preschool period.

Empathy is relevant to many psychiatric conditions. Empathy involves the natural ability to perceive and be sensitive to the emotional states of others. Thus, emotion recognition (ER) abilities are key to understanding empathy. Despite the importance of ER to normal and abnormal social interactions, little is known about how it develops throughout childhood. We examined genetic and environmental influences on children’s ER via facial and vocal cues in 344 7-year- old twin children (59 MZ and 113 same-sex DZ pairs), who were part of the Longitudinal Israeli Study of Twins. ER was assessed with the child version of the Diagnostic Assessment of Nonverbal Accuracy (Nowicki, 2010). For both facial and vocal cues of emotion, twin correlations were not higher for MZ twins than for DZ twins, indicating no heritability for ER in this population. In contrast, correlations were positive for both types of twins (and somewhat higher for DZ twins), indicating a shared environmental effect. This was supported by a bivariate genetic analysis, which did not show a genetic effect but did show shared-environment and non-shared environment effects. This pattern was robust to controlling for twins being of the same sex and age. Effects remained after controlling for background variables such as family income and number of additional siblings. The analysis found a shared environmental correlation between facial and vocal ER (rc =.63), indicating that the shared environmental factors contributed to the overlap between vocal and facial ER. The study highlights the importance of the shared environment to children’s ER.

Empathy has great effect on human well-being, promoting healthy relationships and social competence. Although it is increasingly acknowledged that infants show empathy toward others, individual differences in infants' empathy from the first year of life have rarely been investigated longitudinally. Here we examined how negative reactivity and regulation, two temperament traits that predict empathic responses in older children and adults, relate to infants' empathy. Infants were studied at the ages of nine (N = 275) and 18 (N = 301) months (194 infants were studied at both ages). Empathic responses were assessed by infants' observed reactions to an experimenter's simulated distress. Negative reactivity (fear, sadness, and distress to limitations) and regulation (soothability and effortful control) were assessed by parental reports. Negative reactivity was also examined by infants' observed reactions to an adult stranger (fear) and during interaction with their mothers (displays of sadness/distress). When examined cross-sectionally, infants' fear and distress to limitations associated with self-distress in response to others' distress. In contrast, when examined longitudinally, early sadness and distress to limitations, but not fear, associated with later empathic concern and inquisitiveness. Moreover, this longitudinal relation was moderated by infants' soothability and was evident only for children that had high soothability by the later time-point. Our findings suggest that infants who at an earlier age show negative reactivity, react later in development with more empathy if they achieve sufficient regulation abilities. By that, the findings stress the developmental nature of temperament-empathy relations during infancy.

Research into values at an early age has only started recently, although it has expanded quickly and dynamically in the past years. The purpose of this article is twofold: First, it provides an introduction to a special section that aims to help fill the gap in value development research. The special section brings together four new longitudinal and genetically informed studies of value development from the beginning of middle childhood through early adulthood. Second, this article reviews recent research from this special section and beyond, aiming to provide new directions to the field. With new methods for assessing children's values and an increased awareness of the role of values in children's and adolescents' development, the field now seems ripe for an in-depth investigation. Our review of empirical evidence shows that, as is the case with adults, children's values are organized based on compatibilities and conflicts in their underlying motivations. Values show some consistency across situations, as well as stability across time. This longitudinal stability tends to increase with age, although mean changes are also observed. These patterns of change seem to be compatible with Schwartz's (1992) theory of values (e.g., if the importance of openness to change values increases, the importance of conservation values decreases). The contributions of culture, family, peers, significant life events, and individual characteristics to values are discussed, as well as the development of values as guides for behavior.

Genetically informed research of phenotypes related to morality has proliferated rapidly in the last few years, sparking paradigm shifts from theories based solely on socialization toward ones integrating biological influences. Here, we review recent genetic research in the area of morality that has received the most attention in genetic studies: prosociality — positive emotions, attitudes, and behaviors directed toward others. Individual differences in prosociality emerge early in life, increase in heritability as children develop, and are related to variation in genes regulating neurotransmitter systems central to social affect, cognition, and behavior. The majority of molecular genetic studies have been candidate-based, however genome-wide studies are emerging, with the potential to elucidate novel biological pathways associated with individual differences in morality.

Theories of value development often identify adolescence as the period for value formation, and cultural and familial factors as the sources for value priorities. However, recent research suggests that value priorities can be observed as early as in middle childhood, and several studies, including one on preadolescents (Knafo & Spinath, 2011), have suggested a genetic contribution to individual differences in values. In the current study, 174 pairs of monozygotic and dizygotic 7-year old Israeli twins completed the Picture-Based Value Survey for Children (PBVS–C; Doring et al., 2010). We replicated basic patterns of relations between value priorities and variables of socialisation – gender, religiosity, and socioeconomic status– that have been found in studies with adults. Most important, values of Self-transcendence, Self-enhancement, and Conservation, were found to be significantly affected by genetic factors (29%, 47% and 31% respectively), as well as non-shared environment (71%, 53% and 69% respectively). Openness to change values, in contrast, were found to be unaffected by genetic factors at this age and were influenced by shared (19%) and non-shared (81%) environment. These findings support the recent view that values are formed at earlier ages than had been assumed previously, and they further our understanding of the genetic and environmental factors involved in value formation at young ages.

Early emerging child temperament forms the basis for adult personality and has a multitude of developmental implications. Studies have shown that some aspects of temperament can be observed prenatally, and prenatal parent ratings predict postnatal child temperament, thereby influencing future family dynamics. Little research has examined prenatal mother–father agreement on predictions of temperament, or patterns of cross-dimension associations before birth. Parental expectations of their future child’s temperament were investigated in a sample of pregnant Israeli women and their partners. Three modified temperament questionnaires were used to investigate mother–father agreement and associations between temperament dimensions. There were few significant mean differences between mothers’ and fathers’ expectations of child temperament. Parent agreement within temperament dimensions, and associations across dimensions were consistent with the postnatal literature. Findings indicate that parent impressions of ...

Empathy is the ability to recognize and share in the emotions of others. It can be considered a multifaceted concept with cognitive and emotional aspects. Little is known regarding the underlying neurochemistry of empathy and in the current study we used a neurogenetic approach to explore possible brain neurotransmitter pathways contributing to cognitive and emotional empathy. Both the oxytocin receptor (OXTR) and the arginine vasopressin receptor 1a (AVPR1a) genes contribute to social cognition in both animals and humans and hence are prominent candidates for contributing to empathy. The following research examined the associations between polymorphisms in these two genes and individual differences in emotional and cognitive empathy in a sample of 367 young adults. Intriguingly, we found that emotional empathy was associated solely with OXTR, whereas cognitive empathy was associated solely with AVPR1a. Moreover, no interaction was observed between the two genes and measures of empathy. The current findings contribute to our understanding of the distinct neurogenetic pathways involved in cognitive and emotional empathy and underscore the pervasive role of both oxytocin and vasopressin in modulating human emotions.

Children's prosocial behaviors show considerable variability. Here we discuss the genetic and environmental contributions to individual differences in children's prosocial behavior. Twin research systematically shows, at least from the age of 3 years, a genetic contribution to individual differences in prosocial behavior, both questionnaire-based and observed. This finding is demonstrated across a wide variety of cultures. We discuss the possibility that different prosocial behaviors have different genetic etiologies. A re-analysis of past twin data shows that sharing and comforting are affected by overlapping genetic factors at age 3.5 years. In contrast, the association between helping and comforting is attributed to environmental factors. The few molecular genetic studies of children's prosocial behavior are reviewed, and we point out genome-wide and polygenic methods as a key future direction. Finally, we discuss the interplay of genetic and environmental factors, focusing on both gene×environment interactions and gene-environment correlations.

Corporal punishment (CP) has been associated with deleterious child outcomes, highlighting the importance of understanding its underpinnings. Although several factors have been linked with parents' CP use, genetic influences on CP have rarely been studied, and an integrative view examining the interplay between different predictors of CP is missing. We focused on the separate and joint effects of religiosity, child aggression, parent's gender, and a valine (Val) to methionine (Met) substitution in the brain-derived neurotrophic factor (BDNF) gene. Data came from a twin sample (51% male, aged 6.5 years). We used mothers' and fathers' self-reports of CP and religiosity, and the other parent's report on child aggression. Complete data were available for 244 mothers and their 466 children, and for 217 fathers and their 409 children. The random split method was employed to examine replicability. For mothers, only the effect of religiosity appeared to replicate. For fathers, several effects predicting CP use replicated in both samples: child aggression, child sex, religiosity, and a three-way (GxExE) interaction implicating fathers' BDNF genotype, child aggression and religiosity. Religious fathers who carried the Met allele and had an aggressive child used CP more frequently; in contrast, secular fathers' CP use was not affected by their BDNF genotype or child aggression. Results were also repeated longitudinally in a subsample with age 8-9 data. Findings highlight the utility of a bio-ecological approach for studying CP use by shedding light on pertinent gene-environment interaction processes. Possible implications for intervention and public policy are discussed.

SYNOPSISObjective. Parental expectations before birth may predict children’s development and family environment. Researchers investigated the similarity and differences between expecting mothers and fathers regarding their future parental behavior. Design. Pregnant women (N = 820) and their partners (N = 512) completed questionnaires concerning their future parenting. Results. Mothers’ and fathers’ prenatal parental expectations correlated positively; mothers expected to show more warm, positive parenting and less negative, rejecting parenting compared to fathers; and for most parenting variables, mother–father agreement remained significant only for couples not knowing the fetus’s sex. Conclusions. Patterns of agreement and differences between mothers and fathers regarding future parenting resemble postnatal findings in the literature. Future studies should examine how prenatal expectations relate to postnatal parenting to better understand their significance in child development.

Background Parental warmth has been associated with various child behaviors, from effortful control to callous‐unemotional traits. Factors that have been shown to affect parental warmth include heritability and child behavior. However, there is limited knowledge about which specific genes are involved, how they interact with child behavior, how they affect differential parenting, and how they affect fathers. We examined what affects paternal and maternal warmth by focusing on the child's prosocial behavior and parents’ genotype, specifically a Valine to Methionine substitution at codon 66 in the brain‐derived neurotrophic factor (BDNF) gene. Methods Data was available from a sample of 6.5 year‐old twins, consisting of 369 mothers and 663 children and 255 fathers and 458 children. Self‐reports were used to assess mothers’ and fathers’ warmth. Child prosociality was assessed with the other‐parent report and experimental assessments. Results Mothers’ warmth was not affected by their BDNF genotype, neither as a main effect nor in an interaction with child prosociality. Fathers with the Met allele scored higher on warmth. Additionally, there was a significant interaction between fathers’ BDNF genotype and child prosociality. For fathers with the Met allele there was a positive association between warmth and child prosociality. Conversely, for fathers with the Val/Val genotype there was no association between warmth and child prosociality. Results were repeated longitudinally in a subsample with data on age 8–9 years. A direct within family analysis showed that fathers with the Met allele were more likely than Val/Val carriers to exhibit differential parenting toward twins who differed in their prosocial behavior. The same pattern of findings was found with mother‐rated and experimentally assessed prosociality. Conclusions These results shed light on the genetic and environmental underpinnings of paternal behavior and differential parenting.

This study examined whether children's values, global and abstract motivations serving as guiding principles, are organized similarly to those of adults, whether values can predict individual differences in children's sharing behaviors, and whether the normative nature of the situation influences the expression of these individual differences. Children (N=243, ages 5-12years) participated in a values ranking task as part of a visit to a science museum. The majority of children (n=150) also participated in a task examining costly sharing (i.e., sharing that results in giving up part of one's own resources) and non-costly giving (i.e., giving that does not influence one's own share). Starting from 5years of age, children showed a structure of values similar to that of adolescents and adults, specifically contrasting preferences for opposing values (i.e., self-transcendence with self-enhancement and openness to change with conservation). Importance given to self-transcendence values related positively to costly sharing but not to non-costly giving, indicating that in situations where it is more normative to share, individual differences in values are less expressed in children's actual sharing. In addition, children's sex and age moderated the relation between values and behavior. Children's values are an important aspect of their developing personalities. Taking them into consideration can greatly promote the research of prosocial and normative development as well as our understanding of individual differences in children's behavior.

Based in a transactional framework in which children's own characteristics and the social environment influence each other to produce individual differences in social adjustment, we investigated relationships between children's peer problems and their temperamental characteristics, using a longitudinal and genetically informed study of 939 pairs of Israeli twins followed from early to middle childhood (ages 3, 5, and 6.5). Peer problems were moderately stable within children over time, such that children who appeared to have more peer problems at age 3 tended to have also more peer problems at age 6.5. Children's temperament accounted for 10%–22% of the variance in their peer problems measured at the same age and for 2%–7% of the variance longitudinally. It is important that genetic factors accounted for the association between temperament and peer problems and were in line with a gene–environment correlation process, providing support for the proposal that biologically predisposed characteristics, particularly negative emotionality and sociability, have an influence on children's early experiences of peer problems. The results highlight the need for early and continuous interventions that are specifically tailored to address the interpersonal difficulties of children with particular temperamental profiles.

Views regarding children's influence on their environment and their own development have undergone considerable changes over the years. Following Bell's (1968) seminal paper, the notion of children's influence and the view of socialization as a bidirectional process have gradually gained wide acceptance. However, empirical research implementing this theoretical advancement has lagged behind. This Special Section compiles a collection of new empirical works addressing multiple forms of influential child processes, with special attention to their consequences for children's and others’ positive functioning, risk and resilience. By addressing a wide variety of child influences, this Special Section seeks to advance integration of influential child processes into myriad future studies on development and psychopathology and to promote the translation of such work into preventive interventions.

Affective knowledge, the ability to understand others’ emotional states, is considered to be a fundamental part in efficient social interaction. Affective knowledge can be seen as related to cognitive empathy, and in the framework of Theory of Mind (ToM) as affective ToM. Previous studies found that cognitive empathy and ToM are heritable, yet little is known regarding the specific genes involved in individual variability in affective knowledge. Investigating the genetic basis of affective knowledge is important for understanding brain mechanisms underlying socio-cognitive abilities. The 7-repeat (7R) allele within the third exon of the Dopamine D4 receptor gene (DRD4-III) has been a focus of interest, due to accumulated knowledge regarding its relevance to individual differences in prosocial behavior. A recent study suggests that an interaction between the DRD4-III polymorphism and sex is associated with cognitive empathy among adults. We aimed to examine the same association in two childhood age groups. Children (N = 280, age 3.5 years, N = 283, age 5 years) participated as part of the Longitudinal Israel Study of Twins (LIST). Affective knowledge was assessed through children’s responses to an illustrated story describing different emotional situations, told in a laboratory setting. The findings suggest a significant interaction between sex and the DRD4-III polymorphism, replicated in both age groups. Boy carriers of the 7R allele had higher affective knowledge scores than girls, whereas in the absence of the 7R there was no significant sex effect on affective knowledge. The results support the importance of DRD4-III polymorphism and sex differences to social development. Possible explanations for differences from adult findings are discussed, as are pathways for future studies.

Several related and complementary theoretical frameworks have been proposed to explain the existence of prosocial behavior, despite its potential fitness cost to the individual. These include kin selection theory, proposing that organisms have a propensity to help those to whom they are genetically related, and reciprocity, referring to the benefit of being prosocial, depending on past and future mutual interactions. A useful paradigm to examine prosociality is to compare mean levels of this behavior between monozygotic (MZ) and dizygotic (DZ) twins. Here, we examined the performance of 883 6.5-year-old twins (139 MZ and 302 DZ same-sex 6.5-year-old full twin pairs) in the Differential Productivity Task. In this task, the twins' behaviors were observed under two conditions: working for themselves vs. working for their co-twin. There were no significant differences between the performances of MZ and DZ twins in the prosocial condition of the task. Correlations within the twin dyads were significantly higher in MZ than DZ twins in the self-interested condition. However, similar MZ and DZ correlations were found in the prosocial condition, supporting the role of reciprocity in twins' prosociality towards each other.

This article is part of a Special Issue "Parental Care". Parenting is best understood as a transactional process between parents and their offspring. Each responds to cues in the other, adapting their own behavior to that of their partner. One of the goals of parenting research in the past twenty years has been to untangle reciprocal processes between parents and children in order to specify what comes from the child (child effects) and what comes from the parent (parent effects). Child effects have been found to relate to genetic, pre and perinatal, family-wide, and child-specific environmental influences. Parent effects relate to stresses in the current context (e.g. financial strain, marital conflict), personality and ethnicity but also to adverse childhood experiences (e.g. parental mental health and substance abuse, poverty, divorce). Rodent models have allowed for the specification of biological mechanisms in parent and child effects, including neurobiological and genomic mechanisms, and of the causal role of environmental experience on outcomes for offspring through random assignment of offspring-mother groupings. One of the methods that have been developed in the human and animal models to differentiate between parent and child effects has been to study multiple offspring in the family. By holding the parent steady, and studying different offspring, we can examine the similarities and differences in how parents parent multiple offspring. Studies have distinguished between family average parenting, child-specific parenting and family-wide dispersion (the within family standard deviation). These different aspects of parenting have been differentially linked to offspring behavioral phenotypes.

In this chapter, we review research and some current theory on the development of prosocial responding (including prosocial behavior and empathy-related responding) and possible antecedents/causes, outcomes, and correlates. In the initial section of this chapter, we briefly present a general framework for integrating factors that contribute to prosocial responding. Then the empirical literature related to the development of prosocial behavior, with an emphasis on the emerging literature on early development and development during adolescence, is reviewed. Next we review literature on the potential origins of prosocial responding, including potential biological, cultural, familial, and peer/school factors. Then we address sociocognitive correlates of prosocial responding and the relations of temperamental/personality and social-behavioral individual differences (e.g., aggression) to prosocial behavior and/or empathy-related responding. Due to space constraints, we focus more on current rather than older publications and disproportionately on topics of central importance to prosocial development and issues that have been foci of interest in the past decade. In the final sections of the chapter, gaps in the field and future directions are discussed. Keywords: biological bases; empathy; prosocial behavior; prosocial development; socialization; sympathy

Children vary markedly in their tendency to behave prosocially, and recent research has implicated both genetic and environmental factors in this variability. Yet, little is known about the extent to which different aspects of prosociality constitute a single dimension (the prosocial personality), and to the extent they are intercorrelated, whether these aspects share their genetic and environmental origins. As part of the Longitudinal Israeli Study of Twins (LIST), mothers of 183 monozygotic (MZ) and dizygotic (DZ) 7-year-old twin pairs (51.6% male) reported regarding their children’s prosociality using questionnaires. Five prosociality facets (sharing, social concern, kindness, helping, and empathic concern) were identified. All five facets intercorrelated positively (r > 0.39) suggesting a single-factor structure to the data, consistent with the theoretical idea of a single prosociality trait. Higher MZ than DZ twin correlations indicated genetic contributions to each prosociality facet. A common-factor-common-pathway multivariate model estimated high (69%) heritability for the common prosociality factor, with the non-shared environment and error accounting for the remaining variance. For each facet, unique genetic and environmental contributions were identified as well. The results point to the presence of a broad prosociality phenotype, largely affected by genetics; whereas additional genetic and environmental factors contribute to different aspects of prosociality, such as helping and sharing.

© 2015 Benish-Weisman, Kerem, Knafo-Noam and Belsky. The study considered individual differences in children's ability to adjust to hospitalization and found the length of hospitalization to be related to adaptive psychological functioning for some children. Applying the theoretical framework of three competing models of gene-X-environment interactions (diathesis-stress, differential susceptibility, and vantage sensitivity), the study examined the moderating effect of genetics (DRD4) on the relationship between the length of hospitalization and internalizing and externalizing problems. Mothers reported on children's hospitalization background and conduct problems (externalizing) and emotional symptoms (internalizing), using subscales of the 25-item Strength and Difficulties Questionnaire (1). Data on both hospitalization and genetics were available for 65 children, 57% of whom were females, with an average age of 61.4 months (SD = 2.3). The study found length of hospitalization did not predict emotional and behavior problems per se, but the interaction with genetics was significant; the length of hospitalization was related to diminished levels of internalizing and externalizing problems only for children with the 7R allele (the sensitive variant). The vantage sensitivity model best accounted for how the length of hospitalization and genetics related to children's internalizing and externalizing problems.

The research examined the relationship between multiple social identifications and self-esteem. Early adolescents (M = 11.4, SD = .95) and mid-adolescents (M = 15.9, SD = 1.18) from Germany and Israel (n = 2337) were studied. Respondents described their social identification as students, family members, and as members of the majority national group and reported self-esteem. A longitudinal, cross-sectional and cross-cultural design revealed, as predicted, multiple social identifications related positively to self-esteem concurrently; they also related positively to self-esteem longitudinally over the course of a year. Moreover, multiple social identifications were found to be antecedent to self-esteem, not vice versa. Finally, multiple social identifications were found to decrease over time. The article discusses the contribution of multiple social identifications to self-esteem at different ages and in various contexts.