Predicting the use of corporal punishment: Child aggression, parent religiosity, and the BDNF gene

Environment by environment interactions (ExE) differ across genetic backgrounds (ExExG)

While the terms "gene-by-gene interaction" (GxG) and "gene-by-environment interaction" (GxE) are widely recognized in the fields of quantitative and evolutionary genetics, "environment-byenvironment interaction" (ExE) is a term used less often. In this study, we find that environmentby-environment interactions are a meaningful driver of phenotypes, and moreover, that they differ across different genotypes (suggestive of ExExG). To support this conclusion, we analyzed a large dataset of roughly 1,000 mutant yeast strains with varying degrees of resistance to different antifungal drugs. Our findings reveal that the effectiveness of a drug combination, relative to single drugs, often differs across drug resistant mutants. Remarkably, even mutants that differ by only a single nucleotide change can have dramatically different drug × drug (ExE) interactions. We also introduce a new framework that more accurately predicts the direction and magnitude of ExE interactions for some mutants. Understanding how ExE interactions change across genotypes (ExExG) is crucial not only for modeling the evolution of pathogenic microbes, but also for enhancing our knowledge of the underlying cell biology and the sources of phenotypic variance within populations. While the significance of ExExG interactions has been overlooked in evolutionary and population genetics, these fields and others stand to benefit from understanding how these interactions shape the complex behavior of living systems.

Maternal use of corporal punishment and behavior problems in early childhood: A sibling comparison analysis

BACKGROUND

Previous research demonstrates that there are environmental and genetic factors associated with the use of corporal punishment (CP) and children's behavior problems. Thus, it is difficult to disentangle whether CP has a causal effect on children's developmental outcomes.

OBJECTIVE

This study explored the relationship between maternal use of CP at ages 3-4 years and symptoms of internalizing and externalizing behavior problems between the ages of 6 and 9 years using a sibling comparison design. In doing so, we were able to control for shared environmental factors and partially control for genetic factors that could explain the relationship between CP and behavior problems.

METHODS

This study analyzed data from 11,506 children from the United States. We used generalized linear models to assess the relationship between the use of CP and behavior problems among biological siblings raised in the same home.

RESULTS

At the population level, CP was significantly associated with the development of internalizing behavior problems (β = 0.134, SE = 0.03, p < .001). When comparing siblings, this relationship was no longer significant. In contrast, CP was significantly associated with externalizing behavior problems at both the population (β = 0.233, SE = 0.02, p < .001) and sibling comparison level (β = 0.107, SE = 0.03, p < .001).

CONCLUSION

We did not find evidence to suggest that the association between CP and externalizing behavior problems is due to environmental and genetic factors exclusively. Corroborating previous research, these results suggest that CP may increase the likelihood of externalizing behavior problems.

"He Who Spareth the Rod Hateth His Son": Perceptions Regarding Corporal Punishment Among Ultra-Orthodox Jewish Fathers in Israel

Based on the findings of substantial research, Western professionals today perceive corporal punishment as a threat to child well-being. They also view it as a violation of children's rights. Nonetheless, many minority groups in Western societies still consider it to be a legitimate child-rearing practice. In response to this gap, this article presents qualitative findings from an exploratory context-informed study of Ultra-Orthodox Jewish fathers in Israel, regarding their perceptions and ascribed meanings of corporal punishment. Our exploration was guided by the following research question: What are the constructions, perceptions, beliefs, and meanings associated with corporal punishment among Ultra-Orthodox Litvak fathers in Israel? The thematic analysis of 15 in-depth semi-structured interviews yielded two central themes. The first is the view of corporal punishment as an educational tool with legitimacy based on religious sources and emotion-focused rationales. The second theme deals with different limitations on and guidelines regarding this legitimacy. Children were struck as a result of behavior that parents experienced as extreme, and striking the child in response to religious wrongdoing was viewed as problematic. The fathers interviewed stressed the need to suit the punishment to the child, in terms of the intensity of the blow, frequency, and the age of the child. The fathers also emphasized the importance of the child's subjective experience being one of education as opposed to humiliation. Implications from these findings illustrate the gaps between the Ultra-Orthodox community and professionals who espouse the Western view that prohibits corporal punishment; at the same time, they portray the fathers as expressing an intricate approach toward corporal punishment, with conditions and limitations, as opposed to absolute approval. This article advocates a context-informed approach toward dealing with corporal punishment in minority groups that legitimize the practice. Adopting such an approach may contribute to better cooperation between professionals and their clients from minority groups, and advance child well-being.

Religiosity as a moderator of the links between parental psychological control and children's prosociality

Three studies examined the links between psychological control and prosociality in middle childhood, and the role of religiosity as a moderator. Study 1 (101 Israeli Jewish families, ages 6-9, 50% girls) found a significant interaction, with a negative association between maternal psychological control and children's prosociality in secular but not in religious families. Study 2 (161 Israeli Jewish families, ages 6-12, 48% girls) replicated this interaction for mothers using a continuous religiosity measure. Study 3 (64 Arab Muslim Israeli families, ages 6-8.5, 50% girls) also found a significant interaction, with a positive link between psychological control and prosociality seen at higher, but not at lower, religiosity levels. The findings suggest that religiosity may alter the meaning and consequences of parenting practices.

Divergence of an association between depressive symptoms and a dopamine polygenic score in Caucasians and Asians

A recent study reported a negative association between a putatively functional dopamine (DA) polygenic score, indexing higher levels of DA signaling, and depressive symptoms. We attempted to replicate this association using data from the Duke Neurogenetics Study. Our replication attempt was made in a subsample of 520 non-Hispanic Caucasian volunteers (277 women, mean age 19.78 ± 1.24 years). The DA polygenic score was based on the following five loci: rs27072 (SLC6A3/DAT1), rs4532 (DRD1), rs1800497 (DRD2/ANKK1), rs6280 (DRD3), and rs4680 (COMT). Because the discovery sample in the original study consisted mostly of Asian participants, we also conducted a post hoc analysis in a smaller subsample of Asian volunteers (N = 316, 179 women, mean age 19.61 ± 1.32 years). In the primary sample of non-Hispanic Caucasians, a linear regression analysis controlling for sex, age, socioeconomic status (SES), body mass index, genetic ancestry, and both early and recent life stress, revealed that higher DA polygenic scores were associated with higher self-reported symptoms of depression. This was in contrast to the original association of higher DA polygenic scores and lower depressive symptoms. However, the direction of the association in our Asian subsample was consistent with this original finding. Our results also suggested that compared to the Asian subsample, the non-Hispanic Caucasian subsample was characterized by higher SES, lower early and recent life stress, and lower depressive symptoms. These differences may have contributed to the observed divergence in associations. Collectively, the current findings add to evidence that specific genetic associations may differ between populations and further encourage explicit modeling of race/ethnicity in examining the polygenic nature of depressive symptoms and depression.

The Longitudinal Israeli Study of Twins (LIST) Reaches Adolescence: Genetic and Environmental Pathways to Social, Personality and Moral Development

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 E Is in the G: Gene-Environment-Trait Correlations and Findings From Genome-Wide Association Studies

Genome-wide association studies (GWASs) have shown that pleiotropy is widespread (i.e., the same genetic variants affect multiple traits) and that complex traits are polygenic (i.e., affected by many genetic variants with very small effect sizes). However, despite the growing number of GWASs, the possible contribution of gene-environment correlations (rGEs) to pleiotropy and polygenicity has been mostly ignored. rGEs can lead to environmentally mediated pleiotropy or gene-environment-trait correlations (rGETs), given that an environment that is affected by one genetically influenced phenotype, can in turn affect a different phenotype. By adding correlations with environmentally mediated genetic variants, rGETs can contribute to polygenicity. Socioeconomic status (SES) and the experience of stressful life events may, for example, be involved in rGETs. Both are genetically influenced and have been associated with a myriad of physical and mental disorders. As a result, GWASs of these disorders may find the genetic correlates of SES and stressful life events. Consequently, some of the genetic correlates of physical and mental disorders may be modified by public policy that affects environments such as SES and stressful life events. Thus, identifying rGETs can shed light on findings from GWASs and have important implications for public health.

Recent advances in genetics of aggressive behavior

One of the most important problems of modern neurobiology and medicine is an understanding of the mechanisms of normal and pathological behavior of a person. Aggressive behavior is an integral part of the human psyche. However, environmental risk factors, mental illness and somatic diseases can lead to increased aggression to be the biological basis of antisocial behavior in a human society. An important role in development of aggressive behavior belongs to the hereditary factors that may be linked to abnormal functioning of neurotransmitter systems in the brain yet the underlying genetic mechanisms remain unclear, which is due to a large number of single nucleotide polymorphisms, insertions and deletions in the structure of genes that encode the components of the neurotransmitter systems. The most studied candidate genes for aggressive behavior are serotonergic (TPH1, TPH2, HTR2A, SLC6A4) and dopaminergic (DRD4, SLC6A3) system genes, as well as the serotonin or catecholamine metabolizing enzyme genes (COMT, MAOA). In addition, there is evidence that the hypothalamic-pituitary system genes (OXT, OXTR, AVPR1A, AVPR1B), the sex hormone receptors genes (ER1, AR), neurotrophin (BDNF) and neuronal apoptosis genes (CASP3, BAX) may also be involved in development of aggressive behavior. The results of Genome-Wide Association Studies (GWAS) have demonstrated that FYN, LRRTM4, NTM, CDH13, DYRK1A and other genes are involved in regulation of aggressive behavior. These and other evidence suggest that genetic predisposition to aggressive behavior may be a very complex process.