Behavior Genetics最新文献

This study examined the degree to which genetic and environmental factors contribute to externalizing and internalizing problems in early adolescence, and the role of ethnic discrimination in moderating genetic and environmental influences. The sample included 740 racially/ethnically minoritized adolescent twins (50.3% female, mean age = 11.04 years) from the Adolescent Brain Cognitive Development (ABCD) Study. Adolescents reported on their ethnic discrimination experiences, and parents reported on adolescents' externalizing and internalizing problems. Using univariate biometric twin modeling, we found that both genetic and environmental factors contributed to individual differences in externalizing and internalizing problems. Ethnic discrimination experiences moderated genetic influences on externalizing and internalizing problems, such that genetic influences were higher among youth who experienced higher levels of ethnic discrimination. Ethnic discrimination experiences exacerbate genetic influences on externalizing and internalizing problems among racial/ethnic minoritized adolescents. These findings advance our understanding of the interplay between genetic and cultural factors underlying externalizing and internalizing psychopathology among racially/ethnically minoritized adolescents.

Individuals with high self-esteem experience less social anxiety, fewer depressive symptoms, and exhibit lower neuroticism and higher extraversion. We aimed to explore the genetic and environmental influences behind these associations. Self-esteem, four mental health indicators, and five personality factors were assessed in 1,288 Finnish young adult twins, including 583 complete pairs. The mean age of the participants was 21.9 years (SD = 0.8). Classical twin modelling was used to estimate genetic and environmental correlations. Additionally, regression models were used to examine the association between self-esteem and polygenic scores (PGS) of several mental health traits. Among all participants, self-esteem associated positively with extraversion, agreeableness, and conscientiousness and negatively with depressive symptoms, alexithymia, schizotypal personality, overall mental health problems and neuroticism. These associations were explained by additive genetic factors (19-66% of covariation) and unique environmental factors (36-81% of covariation) when using twin modelling. Self-esteem correlated only with the PGS of subjective well-being in men and women. The proportion of variance of self-esteem explained by the PGSs was minor (1.5% or less). These findings suggest that while self-esteem shares a genetic background with mental health and personality traits, unique environmental factors can also influence these connections. Our findings are consistent with a hypothesis that enhancing self-esteem can have a positive impact on mental health.

In the classical twin design, the assumption that the additive genetic (A) and shared environment (C) variance components are uncorrelated may not hold. If there is positive AC covariance, the C component is overestimated. While many processes can lead to AC covariance, in this study, we focus on two widely-studied mechanisms: Cultural transmission (e.g., genetic nurture), when the parents' genotypes contribute to the effective environment of the child, and sibling interaction, when the genotype of one sibling contributes to the effective environment of another. Several designs use polygenic scores of parents or siblings to detect AC covariance, but these models cannot unambiguously identify the source. A combined model has been proposed, but its power to identify both processes has not been well-studied yet. This study uses exact data simulation to investigate the power to disentangle these processes. Results demonstrated that we can detect AC covariance using either genotyped-sibling or genotyped-parent data, but we cannot resolve its source and thus risk making wrong inferences. These sources of AC covariance can be resolved using genotyped data of both siblings and parents. However, the power analyses show that large samples are required to do so. The sample sizes of published studies may be too small to unambiguously resolve the contributions of the two processes to AC covariance, especially if the effect of one is relatively small compared to the effect of the other. We implement these findings in an R package for genomic simulations, gnomesims, and emphasize the need for whole-family genotyping and modeling.

Gene-environment interaction (G×E) studies analyze how environmental conditions cushion or exacerbate differences in genetic endowments. A gene-environment correlation (rGE) between the polygenic index (PGI) and the environmental condition employed in these G×E studies could bias the estimation of the interaction effect. In this brief report, we discuss the limitations of the commonplace correlation-based test used to verify the orthogonality of the PGI and the environment, and propose to complement it with an additional assessment of the genetic correlation between the phenotype corresponding to the PGI of interest and the environmental condition in the G×E analysis sample using bivariate GREML. Our proposed test is straightforward to perform with the data typically available to G×E researchers, and bypasses that the PGI reflects the environmental conditions of the training sample used to calibrate it. Using UK Biobank data, we provide empirical illustrations covering three environmental conditions relevant for educational attainment. We confirm the orthogonality of the Raising of School Leave Age 1972 educational reform and of gender, although gender did not pass the correlation-based test. However, birth district social class and the genetic propensity for educational attainment appear to be intrinsically intertwined.

The conduct and translation of scientific research is shaped by academic and journalistic publishing. Academic journals issue editorial guidelines and policies that inform how researchers shape and present their studies. Journalists select and report on academic studies for public audiences. Despite the potential importance of journal editors and journalists in the scientific process, little has been done to examine how these groups think about their roles and responsibilities-especially when it comes to ethically sensitive scientific domains like social and behavioral genomics (SBG): the study of whether and how genetic differences between individuals correlate with differences in behaviors such as aggression and outcomes such as educational attainment. To begin filling this gap, we conducted semi-structured interviews with editors working at academic journals that publish SBG research (n = 10) and journalists who have reported on SBG studies (n = 13). Journal editors largely saw themselves as mediators between authors and peer reviewers who help to shepherd along research. Journalists frequently described themselves as translators of science for wide audiences; at times they also saw themselves as interrogators of science. While both groups considered SBG especially ethically sensitive and prone to risks such as misinterpretation, many expressed that systematic ethical review processes and guidelines for SBG are lacking. Further, many deferred the ethical responsibility to minimize risks associated with SBG to others. Our findings highlight the need for more explicit frameworks in academic and journalistic publishing to support the ethically responsible conduct and communication of SBG.

The lack of racial and ethnic diversity in samples used within the field of human genetics research has been well-documented. However, factors driving the under-representation of individuals who are not of European ancestry remains under-explored. The present study aimed to investigate whether willingness to participate in genetic research differed by race and ethnicity, as well as other demographic (e.g., age, gender, religion affiliation, education level) and psychological or individual factors (e.g., trust in research, knowledge of genetics, trait-level worry, health anxiety, altruism, health status) in two ethnically- and racially-diverse samples (N = 2000 via Prolific and N = 264 via an undergraduate psychology research pool). Participants indicated the types of research they would be willing to participate in, including providing saliva or blood samples for genetic research. Approximately, one third of participants endorsed willingness to provide a saliva sample, whereas one quarter endorsed willingness to provide a blood sample. Demographic factors associated with lower willingness included non-white racial/ethnic identities and lower income. Odds did not differ by age or gender identity. Mistrust of research was consistently associated with lower odds of providing a biological sample, whereas higher health anxiety, altruism, and the experience of a health condition was associated with higher odds of participation. Reasons for reluctance were explored, including the influence of compensation, additional information, opportunity for feedback, and study topic. Findings suggest that increasing transparency about how biological samples can be used, involving community leaders, and providing equitable compensation may increase engagement in genetic research, particularly among historically marginalized populations.

Mendelian Randomization (MR) has become an important tool for causal inference in the health sciences. It takes advantage of the random segregation and independent assortment of alleles to control for background confounding factors. In brief, the method works by using genetic variants as instrumental variables, but it depends on the assumption of exclusion restriction, i.e., that the variants affect the outcome exclusively via the exposure variable. Equivalently, the assumption states that there is no horizontal pleiotropy from the variant to the outcome, i.e., no association with the outcome except via the exposure. This assumption is unlikely to hold in nature, so several MR extensions have been developed to increase its robustness against horizontal pleiotropy, though not eliminating the problem entirely (Sanderson et al., in Nat Rev Methods Primer 2:6, 2022). The Direction of Causation (DoC) twin model, which includes information from cross-twin cross-trait correlations to estimate causal paths, was extended with polygenic scores to explicitly model horizontal pleiotropy and a causal path (MR-DoC, Minică et al., in: Behav Genet 48:337-349, 2018). MR-DoC was further extended to accommodate bidirectional causation (MR-DoC2; Castro-de-Araujo et al., in: Behav Genet 53:63-73, 2023). In the present paper, we compared the performance of the DoC, MR-DoC, and MR-DoC2 models to evaluate the effects of phenotypic measurement error, potential unshared (individual-specific) environmental confounding, and statistical power across the three models. It was found that MR-DoC2 is less vulnerable to measurement error than is standard DoC or MR-DoC. The latter two models have biased estimates of causal paths when unshared environmental covariance between exposure and outcome is assumed to be absent.

Past research indicates that genetic and environmental sources contribute to Right-Wing Authoritarianism (RWA) and Social Dominance Orientation (SDO). However, less is known about the differences between the sources of variance in RWA and SDO, and how these sources differ across different developmental stages. Based on data from 1440 twin families, including 1198 complete twin pairs, 435 non-twin full siblings, and 2016 parents of twins from the German TwinLife project, nuclear twin family modeling was used to estimate different genetic and environmental variance components of RWA and SDO, and to examine the extent to which the variance components vary across three age cohorts of twins (average age 15, 21, and 27 years). We hypothesized increasing levels of genetic variance across age cohorts, reflecting more active genotype-environment transactions with development, and declining levels of passive genotype-environment correlation (rGE). The model analyses yielded additive and nonadditive genetic factors as well as influences shared in families due to non-genetic intergenerational transmission from parents to offspring and significant passive rGE for RWA. For SDO, passive rGE components, nonadditive genetic components and non-genetic intergenerational transmission were negligible. However, significant individual environmental sources and those only shared by twins were found for both RWA and SDO. Inconsistent with our expectations, passive rGE and genetic variance did not vary significantly across age cohorts. Counterintuitively, the influence of twin-specific shared environmental factors on RWA was larger in adulthood than adolescence, suggesting increasingly relevant environmental influences across developmental periods. These results have important implications for socio-developmental theories on socio-political attitudes.

Suicidal thoughts and behaviors (STBs) represent a significant public health concern. This study aimed to examine the extent to which polygenic risk scores (PRSs) for suicide attempt and major depression (MD) explain variance in suicidal ideation, plans, and attempts among young adult twins. Data from 2876 participants of European ancestry in the Brisbane Longitudinal Twin Study were analyzed. PRSs for MD and suicidal behavior (SB PRS) were calculated. Multivariate twin modeling was used to estimate genetic and environmental influences on DSM-IV Major Depressive Disorder (MDD) diagnosis and STBs, as well as their associations with PRSs. Heritability estimates were higher for STB phenotypes (51-80%) compared to DSM-IV MDD (39-41%). The MD PRS showed more consistent genetic correlations with DSM-IV MDD, while both PRSs showed modest correlations with suicide outcomes. Multivariate analyses revealed remarkably high genetic correlations among STBs (rA = 0.85-0.99) and moderate genetic correlations with MDD (rA = 0.48-0.65). Environmental factors contributing to DSM-IV MDD risk were largely distinct from those influencing suicide-related phenotypes. This study provided compelling evidence for shared genetic architecture between DSM-IV MDD and STBs. The MD PRS demonstrated more consistent prediction of MDD compared to the SB PRS, though both showed modest correlations with suicide outcomes. These results have important implications for risk assessment strategies, though the substantial unique environmental influences highlight the need to address modifiable environmental risk factors. Future research should focus on replication in larger, more diverse samples and exploring the interactions between genetic risk factors and environmental influences across the lifespan.