Behavior Genetics最新文献

Interest in the role of genetics in influencing key life outcomes such as educational attainment has grown quickly. However, the question of whether genetic influences on educational attainment, on average as well as in conjunction with socioeconomic circumstances, are moderated by macro-level factors has not yet received sufficient attention. This study combines polygenic indices for educational attainment (EA PGI) with high-quality register data in a large sample of Swedish twins of European ancestry born 1920-1999. Employing both conventional between-family and within-family models, the analyses suggest that the influences of education-related genetic propensities on educational attainment have increased in Sweden during the twentieth century, a period featuring major expansions of the Swedish educational system, and decreasing economic inequality. The analyses also suggest that the degree to which socioeconomic background enhances genetic influences on education has decreased across cohorts. Genetic influences on education do not appear to have translated into increased genetic influences on income. Additionally, there is some evidence of floor and ceiling effects in the analyses of dichotomous educational outcomes.

The interpersonal circumplex describes two major axes of personality that guide much of social behavior. Agency, one half of the interpersonal circumplex, refers to relatively stable behavioral patterns that center on self-focused dominance and assertiveness assessed in terms of goals, values, or personality traits. However, the psychometric overlap between agency and the most closely linked big five dimension, extraversion, is not well-established, and little behavior genetic work has documented evidence concerning the role of genetic and environmental influences on trait agency. We used the Midlife Development in the United States study to examine agency, big five, and generativity with replication and robustness checks (N_non-twins = 5,194; N_twins = 1,914; N_Milwaukee = 592). Results indicated that agency was higher in men (d = - 0.24), moderately heritable (44.4%), strongly correlated with extraversion (r =.51), moderately correlated with generativity (r =.36), and approximately 41% of the variance in agency was shared with the big five. The current brief measure of agency across two samples reflected smaller gender differences than historical expectations but supported its distinction from the big five traits at the current levels of analysis.

Diverse tests of cognitive abilities correlate about 0.30 phenotypically and about 0.60 genetically. Their phenotypic overlap defines general cognitive ability (g), driven largely by genetic overlap. Consequently, much of our understanding of the genetic landscape of specific cognitive tests likely reflects g rather than the tests themselves. Removing this g-associated genetic variance will sharpen research on cognitive tests. Here, we use Genomic Structural Equation Modelling (Genomic SEM) to remove shared genetic variance among 12 diverse cognitive tests that capture verbal and nonverbal cognitive domains. We applied Genomic SEM to summary statistics from the largest genome-wide association studies of verbal tests (GenLang Consortium, five tests) and largely nonverbal tests (UK Biobank, seven tests) to chart the genetic landscape of the 12 tests independent of g as compared to uncorrected cognitive tests. We found that SNP heritabilities were nearly as high for the tests corrected for g as uncorrected: the average SNP heritability was 0.16 (SE = 0.02) for the uncorrected tests and 0.13 (SE = 0.02) for the tests corrected for g. Despite this, the genetic landscape of the cognitive tests transformed after controlling for genomic g. The matrix of positive genetic correlations for the cognitive tests (average 0.45) disappeared after g-correction, and some strong negative correlations emerged; for instance, Memory and Word (-0.72), Fluid and Symbol (-0.72), and Tower and Spelling (-0.79). The summary statistics for these g-corrected cognitive tests can be used by researchers to create polygenic scores that focus on the specificity of the tests.

Previous research has supported the use of latent variables as the gold-standard in measuring executive function. However, for logistical reasons genome-wide association studies (GWAS) of executive function have largely eschewed latent variables in favour of singular task measures. As low correlations have traditionally been found between individual executive function (EF) tests, it is unclear whether these GWAS have truly been measuring the same construct. In this study, we addressed this question by performing a factor analysis on summary statistics from eleven GWAS of EF taken from five studies, using GenomicSEM. Models demonstrated a bifactor structure consistent with previous research, with factors capturing common EF and working memory- specific variance. Furthermore, the GWAS performed on this model identified 20 new genomic risk loci for common EF and 4 for working memory reaching genome-wide significance beyond what was found in the constituent GWAS, together resulting in 29 newly mapped EF genes. These results help to clarify the underlying genetic structure of EF and support the idea that EF GWAS are capable of measuring genetic variance related to latent EF constructs even when not using factor scores. Furthermore, they demonstrate that GenomicSEM can combine GWAS with divergent and non-ideal measures of the same phenotype to improve statistical power.

Breastfeeding is hypothesised to benefit child health and cognitive functioning by providing long-chain polyunsaturated fatty acids, which are essential for brain development. In 2007, Caspi et al. found evidence in two cohorts for an interaction between genetic variation in the FADS2 gene (a gene involved in fatty acid metabolism) and breastfeeding on IQ. However, subsequent studies have provided mixed evidence for the existence of an interaction. We investigated the relationship between genetic variation in the FADS2 region, breastfeeding, and their interaction in up to 335,650 individuals from the UK Biobank. We tested for the interaction over a range of cognitive functioning tests, as well as educational attainment and other traits thought to be influenced by breastfeeding, including cardiometabolic traits, number of offspring, and atopic allergy. FADS2 alleles associated with an increase in docosahexaenoic acid in blood serum (the C allele of rs174575) were associated with decreased verbal-numerical reasoning ( $p=2.28\times {10}^{-5}$ ) and triglycerides ( $p=1.40\times {10}^{-41}$ ), increased number of offspring ( $p=3.40\times {10}^{-5}$ ), total cholesterol ( $p=5.28\times {10}^{-36}$ ), HDL ( $p=1.42\times {10}^{-51}$ ), and LDL cholesterol ( $p=1.46\times {10}^{-21}$ ). We observed no evidence of an interaction in any of the traits, regardless of the modelling strategy on any cognitive or non-cognitive traits. We postulate that the previous positive findings are likely to be spurious, perhaps due to lack of appropriate control for latent population structure.

This paper provides an overview of the most recent assessment, collected in early midlife, of the FinnTwin12 cohort, a population-based study of Finnish twins born in 1983-1987. The twins were invited to complete an online survey assessing a range of variables, including physical and mental health, alcohol use and problems, other substance use, and early midlife environments (e.g., parenthood). In total, 2,085 individuals (~ 40% of the original sample) completed the survey (551 complete twin pairs, 58.7% female, 37.3% monozygotic, M_age = 37.2 years, SD = 1.47 years, age range = 34-39 years). Individuals who participated were more likely to be female, monozygotic, and have higher parental education and less hyperactivity/impulsivity and aggression at age 12 when compared to individuals who were invited but did not participate. Parental alcohol misuse and the twins' alcohol use and misuse at age 14 were not related to study retention. Alcohol misuse in early midlife was positively associated with nicotine dependence, lifetime use of cannabis and other drugs, trauma exposure, and depressive symptoms, and negatively associated with physical health and having biological children. These new data expand upon the wealth of measures collected as part of previous assessments, expanding the scope of work on the etiology and correlates of alcohol misuse within a longitudinal, genetically-informed framework. In addition to these new survey measures, we are planning an in-person assessment to collect physiological measurements and conduct additional in-depth phenotyping on a subset of twins who have been more intensively studied over the years.

Tattooing has become increasingly common in recent decades, yet little is known regarding factors that influence tattoo behavior. Sources of influence will be important, for instance in aiding studies of long-term health effects. From the population-based Danish Twin Tattoo Cohort established in 2021, the study included 9,173 randomly selected twins born 1920-2004. Among these were 4,790 (52%) responders to a questionnaire on tattooing and lifestyle factors. There were 55% females, 22% were monozygotic twins, and the median age was 51 years. Shared influence of tattooing over time was assessed by comparing monozygotic and dizygotic twin pairs. Responders were population representative on sex, age, and lifestyle factors. The cumulative incidence of being tattooed before age 25 years increased markedly from 6% (95% CI: 4-7%) for males and 0% (0-1%) for females born in 1925-1960 to 30% (25-35%) for males and 41% (37-46%) for females born in 1981-2004. Tattooing was over twice as common among ever smokers compared to never smokers born in 1981-2004 (average smoking effect at age 25 years: 36% (29-43%)). The likelihood of a twin getting tattooed if the co-twin is tattooed, was 2.0 (1.4-2.6) and 1.8 (1.5-2.2) times higher, for monozygotic and dizygotic twins, respectively. The findings indicate that variation in the likelihood of becoming tattooed is primarily explained by shared environmental factors 65% (35-95%), and that genetic influences explained little of this variation. This study demonstrates that strong environmental exposures shared by twin siblings irrespective of degree of genetic relatedness drive the choice for getting tattooed. We conclude that tattooing is a cultural group clustering phenomenon that goes beyond genetically oriented behavioral characteristics.

Social behavior is a common though variable trait across animal species. How much of the variation in social behavior is due to biological common mechanisms across animal species is unknown. In this study we examined to what extent human genetic variation in sociability is affected by pathways shared with Caenorhabditis elegans and whether any conserved sociability-linked genes show enhanced levels of essential functions and interactivity. We found inconsistent evidence of increased conservation with more thorough analyses resulting in no evidence of increased conservation of human sociability-linked genes. Conserved genes were highly interactive compared to nonconserved and random genes, while only a limited number of genetic interactions were found to be conserved. No evidence was found for enrichment of social phenotypes in C. elegans orthologs of human sociability-linked genes while evidence for associations with essential functions were limited. The activin A receptor type 2A (ACVR2A) gene appears to play a role in social behavior in both humans and C. elegans, making it an interesting gene for further study.

This study examined whether adolescent depressive and anxiety symptoms were differentially associated with alcohol use behaviors, and how these associations were explained by genetic, shared, and nonshared environmental influences. Participants were from the Nonshared Environment and Adolescent Development project of same-sex twin/sibling pairs from 720 families. Twin/sibling depressive and anxiety symptoms were measured by self-report at Time 1 (M_age = 13.71 years, range = 9-18 years). Alcohol initiation and alcohol use severity were measured by self-report three years after Time 1 (age range = 12-21 years). Phenotypic Cholesky models were used to estimate the variance of depressive symptoms and the unique variance of anxiety symptoms (independent of depressive symptoms), and how these variances were associated with alcohol initiation and alcohol use severity. Biometric Cholesky models then estimated contributions of genetic, shared and nonshared environmental influences to these variances and covariances. Antisocial behaviors were included in all analyses to account for their associations with depressive symptoms, anxiety symptoms and alcohol use behaviors. Analyses were conducted using the full, the younger half, and the older half of the sample to explore age differences in all associations. Depressive or anxiety symptoms were not associated with alcohol use behaviors after controlling for variance shared with antisocial behaviors, although age-specific analyses suggested some potential effects to explore in future studies for late adolescence. To conclude, longitudinal associations between depressive or anxiety symptoms and alcohol use behaviors during adolescence were mainly driven by the general psychopathology factor shared between internalizing and externalizing problems.