Reut Avinun

Parenting as a Reaction Evoked by Children’s Genotype A Meta-Analysis of Children-as-Twins Studies

Parenting has been extensively studied but mostly as a causal factor influencing child outcomes. The aim of the current article is to examine the child’s side of the relationship by meta-analyzing studies which used quantitative genetic methods that provide leverage in understanding causality. A meta-analysis of 32 children-as-twins studies of parenting revealed a heritability estimate of 23%, thus indicating that genetically influenced behaviors of the child affect and shape parental behavior. The shared- and nonshared-environmental estimates, which amounted to 43% and 34%, respectively, indicate not only substantial consistency in parental behavior but also differential treatment within the family. Assessment method, age, and parenting dimension were found to be significant moderators of these influences. Our findings stress the importance of accounting for genotype-environment correlations in child-development studies and call into question previous research that interpreted correlational results in unidirectional terms with parenting as the sole causal factor.

AVPR1A Variant Associated with Preschoolers' Lower Altruistic Behavior

The genetic origins of altruism, defined here as a costly act aimed to benefit non-kin individuals, have not been examined in young children. However, previous findings concerning adults pointed at the arginine vasopressin receptor 1A (AVPR1A) gene as a possible candidate. AVPR1A has been associated with a range of behaviors including aggressive, affiliative and altruistic phenotypes, and recently a specific allele (327 bp) of one of its promoter region polymorphisms (RS3) has been singled out in particular. We modeled altruistic behavior in preschoolers using a laboratory-based economic paradigm, a modified dictator game (DG), and tested for association between DG allocations and the RS3 “target allele.” Using both population and family-based analyses we show a significant link between lower allocations and the RS3 “target allele,” associating it, for the first time, with a lower proclivity toward altruistic behavior in children. This finding helps further the understanding of the intricate mechanisms underlying early altruistic behavior.

Human maternal behaviour is associated with arginine vasopressin receptor 1A gene

Parenting is one of the main influences on childrens early development, and yet its underlying genetic mechanisms have only recently begun to be explored, with many studies neglecting to control for possible child effects. This study focuses on maternal behaviour and on an allele at the RS3 promoter region of the arginine vasopressin receptor 1A (AVPR1A) gene, previously associated with autism and with higher amygdala activation in a face-matching task. Mothers were observed during a free-play session with each of their 3.5-year-old twins. Multilevel regression analyses revealed that mothers who are carriers of the AVPR1A RS3 allele tend to show less structuring and support throughout the interaction independent of the childs sex and RS3 genotype. This finding advances our understanding of the genetic influences on human maternal behaviour.

Differential Genetic Susceptibility to Child Risk at Birth in Predicting Observed Maternal Behavior

This study examined parenting as a function of child medical risks at birth and parental genotype (dopamine D4 receptor; DRD4). Our hypothesis was that the relation between child risks and later maternal sensitivity would depend on the presence/absence of a genetic variant in the mothers, thus revealing a gene by environment interaction (GXE). Risk at birth was defined by combining risk indices of childrens gestational age at birth, birth weight, and admission to the neonatal intensive care unit. The DRD4-III 7-repeat allele was chosen as a relevant genotype as it was recently shown to moderate the effect of environmental stress on parental sensitivity. Mothers of 104 twin pairs provided DNA samples and were observed with their children in a laboratory play session when the children were 3.5 years old. Results indicate that higher levels of risk at birth were associated with less sensitive parenting only among mothers carrying the 7-repeat allele, but not among mothers carrying shorter alleles. Moreover, mothers who are carriers of the 7-repeat allele and whose children scored low on the risk index were observed to have the highest levels of sensitivity. These findings provide evidence for the interactive effects of genes and environment (in this study, children born at higher risk) on parenting, and are consistent with a genetic differential susceptibility model of parenting by demonstrating that some parents are inherently more susceptible to environmental influences, both good and bad, than are others.

The longitudinal Israeli study of twins (LIST) - an integrative view of social development

The Longitudinal Israeli Study of Twins (LIST) is a social developmental study, which implements social-developmental, molecular genetic, epigenetic, and behavioral genetic methods to advance knowledge on the development of individual differences in social behavior. Twins are followed from the age of three and both observational and parental-questionnaire data are collected on their empathy, temperament, and pro-social behavior. The parenting styles of parents are also evaluated using self-reports and observations and DNA samples are collected from parents and twins. In the current paper, we provide a review of our recent work and discuss the future aims of the LIST.

Parental brain-derived neurotrophic factor genotype, child prosociality, and their interaction as predictors of parents’ warmth

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 childs prosocial behavior and parents’ genotype, specifically a Valine to Methionine substitution at codon 66 in the brain‐derived neurotrophic factor (BDNF) gene.

Oxytocin and vasopressin in human sociality and social psychopathologies

The mammalian neurohypophyseal peptide hormones oxytocin and vasopressin act to mediate human social behavior – they affect trust and social relationships and have an influence on avoidance responses. Describing the evolutionary roots of the effects that these neuropeptides have on behavior, this book examines remarkable parallel findings in both humans and non-human animals. The chapters are structured around three key issues: the molecular and neurohormonal mechanisms of peptides; phylogenetic considerations of their role in vertebrates; and their related effects on human behavior, social cognition, and clinical applications involving psychiatric disorders such as autism. A final chapter summarizes current research perspectives and reflects on the outlook for future developments. Providing a comparative overview and featuring contributions from leading researchers, this is a valuable resource for graduate students, researchers, and clinicians in this rapidly developing field.

Oxytocin, Vasopressin and Related Peptides in the Regulation of Behavior: Oxytocin and vasopressin in human sociality and social psychopathologies

The mammalian neurohypophyseal peptide hormones oxytocin and vasopressin act to mediate human social behavior – they affect trust and social relationships and have an influence on avoidance responses. Describing the evolutionary roots of the effects that these neuropeptides have on behavior, this book examines remarkable parallel findings in both humans and non-human animals. The chapters are structured around three key issues: the molecular and neurohormonal mechanisms of peptides; phylogenetic considerations of their role in vertebrates; and their related effects on human behavior, social cognition, and clinical applications involving psychiatric disorders such as autism. A final chapter summarizes current research perspectives and reflects on the outlook for future developments. Providing a comparative overview and featuring contributions from leading researchers, this is a valuable resource for graduate students, researchers, and clinicians in this rapidly developing field.