Daily general discrimination predicts changes in trait negative affectivity: A 30-year cohort longitudinal study using a random-intercept cross-lagged panel model.

OBJECTIVE: Increasing evidence indicates discrimination is an emerging risk factor for reducing psychological well-being. Negative affectivity is a personality trait that has been associated with discrimination. Yet, few studies to date have examined the longitudinal relationship between discrimination and personality. The current study addresses this gap by examining how general discrimination and negative affectivity influence each other longitudinally. METHOD: The Midlife in the United States (MIDUS) dataset was used for the current study. The MIDUS sample (N = 4244) was predominately white (90.7%), 52% female, and had an average age of 46 years old. Individuals completed follow-up measures 10 and 20 years after baseline. Data were analyzed using a random-intercept cross-lagged panel model. RESULTS: Individuals that scored higher on trait negative affectivity also tended to score higher on perceived daily discrimination. We found general perceived discrimination at age 55 unidirectionally predicted changes in negative affectivity around retirement age, but not from age 45 to 55. In contrast, negative affectivity did not significantly predict increases in perceived discrimination at any timepoint. CONCLUSION: Our results indicate that perceived discrimination has pernicious impacts on well-being up to a decade later and may do so by increasing an individual's tendency to experience negative emotions (i.e., negative affectivity).

Where you live matters: visualizing environmental effects on reading attainment.

BACKGROUND: The way in which socioeconomic status (SES) moderates the etiology of reading attainment has been explored many times, with past work often finding that genetic influences are suppressed under conditions of socioeconomic deprivation and more fully realized under conditions of socioeconomic advantage: a gene-SES interaction. Additionally, past work has pointed toward the presence of gene-location interactions, with the relative influence of genes and environment varying across geographic regions of the same country/state. METHOD: This study investigates the extent to which SES and geographical location interact to moderate the genetic and environmental components of reading attainment. Utilizing data from 2,135 twin pairs in Florida (mean age 13.82 years, range 10.71-17.77), the study operationalized reading attainment as reading comprehension scores from a statewide test and SES as household income. We applied a spatial twin analysis procedure to investigate how twin genetic and environmental estimates vary by geographic location. We then expanded this analysis to explore how the moderating role of SES on said genetic and environmental influences also varied by geographic location. RESULTS: A gene-SES interaction was found, with heritability of reading being suppressed in lower- (23%) versus higher-SES homes (78%). The magnitude of the moderating parameters were not consistent by location, however, and ranged from -0.10 to 0.10 for the moderating effect on genetic influences, and from -0.30 to 0.05 for the moderating effect on environmental influences. For smaller areas and those with less socioeconomic variability, the magnitude of the genetic moderating parameter was high, giving rise to more fully realized genetic influences on reading there. CONCLUSIONS: SES significantly influences reading variability. However, a child's home location matters in both the overall etiology and how strongly SES moderates said etiologies. These results point toward the presence of multiple significant environmental factors that simultaneously, and inseparably, influence the underlying etiology of reading attainment.

Early classroom reading gains moderate shared environmental influences on reading comprehension in adolescence.

BACKGROUND: Reading is important for children's success in school and beyond, yet many adolescents fail to reach expected levels of proficiency. This highlights the need to better understand the factors that influence reading effectiveness over time, including genes and environment. Greater expression of genetic influence on first- and second-grade reading fluency has been observed in higher quality classroom reading environments. To what degree this early environment continues to influence genetic and other environmental influences on later reading is unknown and was tested in this study. METHODS: The quality of the early classroom reading environment was approximated by gains in oral reading fluency (ORF) across the school year among first- or second-grade classmates of 546 MZ and 1,016 DZ twin children (mean age = 7.13 years; SD = 0.45) who had reading comprehension scores from a state-wide mandatory test in school year 2013-2014 when most twin pairs were in seventh to tenth grade (mean age = 14.41; SD = 1.13) in a variable called Class ORF Gain. Biometrical models were fit to the data to assess whether Class ORF Gain moderated the genetic, shared environmental and/or nonshared environmental variance associated with adolescent reading comprehension. RESULTS: Class ORF Gain moderated shared environmental influences on reading comprehension 6-9 years later. When early classroom reading gains were poor, variability in reading comprehension in adolescence was high and was associated largely with shared environmental influences. When early classroom reading gains were good, overall and shared environmentally influenced variability in adolescent reading comprehension was lower so that genetic influences were most relevant in explaining that variability. CONCLUSIONS: Our findings suggested that classroom reading environment experienced when children were learning to read had a lasting influence on the factors underlying variability in later reading effectiveness.

The Florida State Twin Registry.

The Florida State Twin Registry has existed for nearly two decades, and it grew primarily over 10 years as part of the Florida Learning Disability Research Center at Florida State University. The registry contains 2753 sets of twins and other multiples in Florida. The mean age of the sample currently is 17.96 years (SD = 2.05). The registry is diverse in terms of race and ethnicity (49% White, 19% African American, 24% Hispanic and 8% mixed or other). The characteristics of the samples and measures in the studies that served to build the registry are outlined.

The National Project on Achievement in Twins.

The National Project on Achievement in Twins (NatPAT) began in 2017 as part of the third funding cycle of the Florida Learning Disabilities Research Center, a program project grant funded by the Eunice Kennedy Shriver National Institute of Child Health and Development. NatPAT will have a nationally representative sample of elementary school-aged twins in the United States. The overall goal of the project is to uncover salient factors, including genetic and environmental influences, which contribute to the co-development of reading and math performance during the critical developmental period of elementary school. Here we present the specific aims, methods and materials, and future directions of the project.

Twin Family Registries Worldwide: An Important Resource for Scientific Research.

Much progress has been made in twin research since our last special issue on twin registries (Hur, Y.-M., & Craig, J. M. (2013). Twin Research and Human Genetics, 16, 1-12.). This special issue provides an update on the state of twin family registries around the world. This issue includes 61 papers on twin family registries from 25 countries, of which 3 describe consortia based on collaborations of several twin family registries. The articles included in this issue discuss the establishment and maintenance of twin registries, recruitment strategies, methods of zygosity assessment, research aims and major findings from twin family cohorts, as well as other important topics related to twin studies. The papers amount to approximately 1.3 million monozygotic, dizygotic twins and higher order multiples and their family members who participate in twin studies around the world. Nine new twin family registries have been established across the world since our last issue, which demonstrates that twin registers are increasingly important in studies of the determinants and correlates of complex traits from disease susceptibility to healthy development.

Longitudinal Associations Among Reading-Related Skills and Reading Comprehension: A Twin Study.

This study investigated the etiology of longitudinal relations among kindergarten prereading skills, first-grade word level reading skills, and seventh-grade reading comprehension in 265 monozygotic and 459 dizygotic twin pairs (Mage  = 6.29 years in kindergarten) from the Florida Twin Project on Reading. Using a quadvariate Cholesky decomposition, results showed genetic, shared, and nonshared environmental overlap among prereading skills, word level reading skills, and reading comprehension. In addition, genetic and shared environmental overlap was indicated among word level reading skills and reading comprehension, outside the influence of prereading skills. After accounting for overlapping, there remained moderate genetic and nonshared environmental influence specific to reading comprehension. Implications for reading education are discussed.

Examining the Etiology of Reading Disability as Conceptualized by the Hybrid Model.

A fairly recent definition of reading disability (RD) is that in the form of a hybrid model. The model views RD as a latent construct that is manifested through various observable unexpected impairments in reading related skills and through inadequate response to intervention. The current report evaluated this new conceptualization of RD from an etiological perspective. The sample consisted of 2737 twin pairs in first through fourth grade (Mage = 8.52) from the Florida Twin Project on Reading. Using twin analyses, results showed that a substantial proportion of genetic variance, a small proportion of shared environmental, and a small proportion of non-shared environmental variance was attributed to the RD factor. Findings suggest that the etiological architecture of RD closely mirrors the structure of the hybrid model of RD.

Oppositional defiant disorder dimensions: genetic influences and risk for later psychopathology.

BACKGROUND: This study was undertaken to determine how well two oppositional defiant disorder (ODD) dimensions (irritable and headstrong/hurtful) assessed in childhood predict late adolescent psychopathology and the degree to which these outcomes can be attributed to genetic influences shared with ODD dimensions. METHODS: Psychopathology was assessed via diagnostic interviews of 1,225 twin pairs at ages 11 and 17. RESULTS: Consistent with hypotheses, the irritable dimension uniquely predicted overall internalizing problems, whereas the headstrong/hurtful dimension uniquely predicted substance use disorder symptoms. Both dimensions were predictive of antisocial behavior and overall externalizing problems. The expected relationships between the irritable dimension and specific internalizing disorders were not found. Twin modeling showed that the irritable and headstrong/hurtful dimensions were related to late adolescent psychopathology symptoms through common genetic influences. CONCLUSIONS: Symptoms of ODD in childhood pose a significant risk for various mental health outcomes in late adolescence. Further, common genetic influences underlie the covariance between irritable symptoms in childhood and overall internalizing problems in late adolescence, whereas headstrong/hurtful symptoms share genetic influences with substance use disorder symptoms. Antisocial behavior and overall externalizing share common genetic influences with both the irritable and headstrong/hurtful dimensions.

Genetic and environmental influences on early literacy skills across school grade contexts.

Recent research suggests that the etiology of reading achievement can differ across environmental contexts. In the US, schools are commonly assigned grades (e.g. 'A', 'B') often interpreted to indicate school quality. This study explored differences in the etiology of early literacy skills for students based on these school grades. Participants included twins drawn from the Florida Twin Project on Reading (n = 1313 pairs) aged 4 to 10 years during the 2006-07 school year. Early literacy skills were assessed with DIBELS subtests: Oral Reading Fluency (ORF), Nonsense Word Fluency (NWF), Initial Sound Fluency (ISF), Letter Naming Fluency (LNF), and Phoneme Segmentation Fluency (PSF). School grade data were retrieved from the Florida Department of Education. Multi-group analyses were conducted separately for subsamples defined by 'A' or 'non-A' schools, controlling for school-level socioeconomic status. Results indicated significant etiological differences on pre-reading skills (ISF, LNF, and PSF), but not word-level reading skills (ORF and NWF). There was a consistent trend of greater environmental influences on pre-reading skills in non-A schools, arguably representing 'poorer' environmental contexts than the A schools. Importantly, this is the case outside of resources linked with school-level SES, indicating that something about the direct environment on pre-reading skills in the non-A school context is more variable than for A schools.

Nightmares and nonsuicidal self-injury: The mediating role of emotional dysregulation.

INTRODUCTION: Nonsuicidal self-injury (NSSI) is a transdiagnostic behavior associated with significant psychopathology. Research has shown a positive association between sleep disturbances, (e.g., nightmares and insomnia), and suicidal behavior, however, the relation between NSSI and sleep disturbances has yet to be examined. Sleep disturbances have been found to have a causal role in problems with emotional dysfunction. Specifically, sleep disturbances inhibit the emotion processing function of sleep. Importantly, a majority of individuals engage in NSSI to regulate intense emotions, and it is possible that sleep disturbances increase propensity for NSSI by contributing to dysregulated emotions. METHODS: In two cross-sectional studies, the present research examined whether insomnia symptoms and nightmares were related to NSSI in a clinical sample (Study 1, N = 313) and in a university sample (Study 2, N = 152). Furthermore, the hypothesis that emotional dysregulation would atemporally mediate the relationship between sleep disturbances and NSSI was tested in Study 2. RESULTS: Findings showed that nightmares, but not insomnia symptoms, were associated with NSSI while controlling for depressive symptoms. This pattern of findings was consistent across both clinical and university samples, which underscores the robustness of the finding. Further, the relationship between nightmares and NSSI was fully mediated by emotional dysregulation. CONCLUSION: The present research provides initial evidence that nightmares are atemporally associated with an increased propensity for NSSI by contributing to emotional dysregulation, and provides support for the emotion regulation function of dreams.

Exploring the Co-Development of Reading Fluency and Reading Comprehension: A Twin Study.

This study explores the co-development of two related but separate reading skills, reading fluency and reading comprehension, across Grades 1-4. A bivariate biometric dual change score model was applied to longitudinal data collected from 1,784 twin pairs between the ages of 6 and 10 years. Grade 1 skills were influenced by highly overlapping genetic and environmental factors. Growth in both skills was influenced by highly overlapping shared environmental factors. Cross-lagged parameters indicated bidirectional effects, with stronger effects from fluency to comprehension change than from comprehension to fluency change.

Perceived Family Cohesion Moderates Environmental Influences on Prosocial Behavior in Nigerian Adolescent Twins.

Research shows that perceived family cohesion is positively related to prosocial behavior in adolescents. In this study, we investigated heritability of prosocial behavior (PB) and perceived family cohesion (FC) among Nigerian twins attending public schools in Lagos State, Nigeria (mean age = 14.7 years, SD = 1.7 years), and explored the issue of whether children's perception of cohesive family environment moderated genetic and environmental influences on (PB). The PB scale of the Strengths and Difficulties Questionnaire and the FC scale of the Family Adaptability and Cohesion Evaluation Scale III were completed by 2,376 twins (241 monozygotic (MZ) male, 354 MZ female, 440 dizygotic (DZ) male, 553 DZ female, and 788 opposite-sex DZ twins). A general sex-limitation and the bivariate genotype by environment interaction (G×E) models were applied to the data. The general sex-limitation model showed no significant sex differences, indicating that additive genetic and non-shared environmental influences were, 38% (95% CI = 31, 46) and 62% (95% CI = 54, 69) for PB and 33% (95% CI = 24, 40) and 67% (95% CI = 60, 76) for FC in both sexes. These estimates were similar to those found in Western and Asian twin studies to date. The correlation between PB and FC was 0.36. The best-fitting bivariate G×E model indicated that FC significantly moderated non-shared environmental influence unique to PB (E×E interaction). Specifically, non-shared environmental contributions to PB were highest when FC was lowest, and decreased as the levels of FC increased. However, genetic variances in PB were stable across all levels of FC. These findings suggest that FC reduces individual differences in PB by changing non-shared environmental experiences rather than genetic factors in PB.

Home Environmental and Behavioral Risk Indices for Reading Achievement.

The goal of this study was to identify home environmental and temperament/behavior variables that best predict standardized reading comprehension scores among school-aged children. Data from 269 children aged 9-16 (M = 12.08; SD = 1.62) were used in discriminant function analyses to create the Home and Behavior indices. Family income was controlled in each index. The final Home and Behavior models each classified around 75% of cases correctly (reading comprehension at grade level vs. not). Each index was then used to predict other outcomes related to reading. Results showed that Home and/or Behavior accounted for 4-7% of the variance in reading fluency and spelling and 20-35% of the variance in parent-rated problems in math, social anxiety, and other dimensions. These metrics show promise as environmental and temperament/behavior risk scores that could be used to predict and potentially screen for further assessment of reading related problems.

The Effects of Genetic and Environmental Factors on Writing Development.

Researchers have identified sources of individual differences in writing across beginning and developing writers. The aim of the present study was to further clarify the sources of this variability by investigating the extent to which there are differences in genetic and environmental factors underlying the associations between lexical diversity, syntactic knowledge, and semantic cohesion knowledge in relation to writing. Differences were examined across two developmental phases of writing: beginning (i.e., elementary school) and developing (i.e., middle school). Participants included 262 twin pairs (Mage = 10.88 years) in elementary school and 247 twin pairs (Mage = 13.21 years) in middle school. Twins were drawn from the Florida Twin Project on Reading, Behavior, and Environment. Biometric models were conducted separately for subgroups defined by phase of writing development. Results indicated significant etiological differences in writing components across the two phases, such that effects associated with genes and non-shared environment were greater while effects associated with shared environment were lower in developing writers as compared to beginning writers. Furthermore, results showed that child-specific environment was the largest contributor to individual differences in writing components and their covariation for both beginning and developing writers. These results imply that even direct instruction about writing in schools may be having different effects on children based on their unique experiences.

The genome of the emerging barley pathogen Ramularia collo-cygni.

BACKGROUND: Ramularia collo-cygni is a newly important, foliar fungal pathogen of barley that causes the disease Ramularia leaf spot. The fungus exhibits a prolonged endophytic growth stage before switching life habit to become an aggressive, necrotrophic pathogen that causes significant losses to green leaf area and hence grain yield and quality. RESULTS: The R. collo-cygni genome was sequenced using a combination of Illumina and Roche 454 technologies. The draft assembly of 30.3 Mb contained 11,617 predicted gene models. Our phylogenomic analysis confirmed the classification of this ascomycete fungus within the family Mycosphaerellaceae, order Capnodiales of the class Dothideomycetes. A predicted secretome comprising 1053 proteins included redox-related enzymes and carbohydrate-modifying enzymes and proteases. The relative paucity of plant cell wall degrading enzyme genes may be associated with the stealth pathogenesis characteristic of plant pathogens from the Mycosphaerellaceae. A large number of genes associated with secondary metabolite production, including homologs of toxin biosynthesis genes found in other Dothideomycete plant pathogens, were identified. CONCLUSIONS: The genome sequence of R. collo-cygni provides a framework for understanding the genetic basis of pathogenesis in this important emerging pathogen. The reduced complement of carbohydrate-degrading enzyme genes is likely to reflect a strategy to avoid detection by host defences during its prolonged asymptomatic growth. Of particular interest will be the analysis of R. collo-cygni gene expression during interactions with the host barley, to understand what triggers this fungus to switch from being a benign endophyte to an aggressive necrotroph.

Utility of fetal MRI for workup of fetal central nervous system anomalies in an Australian maternal-fetal medicine cohort.

OBJECTIVES: To evaluate how fetal MRI is influencing current clinical practice and outcomes for central nervous system (CNS) anomalies in the Australian maternal-fetal medicine (MFM) setting. MATERIAL AND METHODS: Retrospective audit of cases January 2008-August 2013 referred for MFM ultrasound and MRI for suspected fetal CNS anomaly. Demographics, referral information, initial MFM diagnoses and investigations, MRI diagnoses, subsequent pregnancy management and perinatal outcome were examined. RESULTS: Fifty-seven women (41 singleton, 16 twin pregnancies) were seen at mean gestation of 23.7 ± 6.5 weeks. Major referral indications included ventriculomegaly (VM, 39%) and posterior fossa anomaly (PFA, 18%). MRI was performed at mean 27.2 ± 5.3 weeks. Diagnosis was altered from ultrasound in 31/57 cases (54%); 14 improving and 17 worsening prognosis. MRI findings worsening prognosis were more significant VM and PFA, agenesis of the corpus callosum, neuronal migration disorders and intraventricular haemorrhage. TOP or selective reduction occurred in 11 of 57 cases after full clinical workup (six where MRI worsened prognosis, five where MRI confirmed US poor prognosis). Mean gestation at birth was 37.2 ± 4.1 weeks for continuing pregnancies. There were nine cases of additional postnatal diagnoses, including four CNS anomalies. After neonatal workup, physical and/or developmental delay was anticipated for at least 14 of 43 (33%) infants. CONCLUSIONS: MRI added significant diagnostic information in about half the cases referred for workup of suspected CNS anomaly. In six of 17 cases where MRI worsened prognosis, TOP was chosen. Both additional CNS and non-CNS anomalies were diagnosed postnatally in 20%, emphasising the uncertain prognosis for, and evolution of, suspected CNS anomaly in fetuses.

The association between affective psychopathic traits, time incarcerated, and cortisol response to psychosocial stress.

Previous research has demonstrated that psychopathic personality traits are significantly predictive of blunted cortisol reactivity to a performance-based stressor task (Trier Social Stress Test; TSST) in college students. However, the relationship between cortisol reactivity and psychopathy has not been explored in high risk samples such as incarcerated populations. Further, the role of imprisonment in relation to cortisol stress reactivity has not been previously explored, but could have practical and conceptual consequences in regard to rehabilitation and biological sensitivity to context, respectively. The current study tested the hypotheses that both psychopathic personality traits and amount of time incarcerated are related to cortisol blunting in response to stress among incarcerated young adults. A sample of 49 young adult male offenders was recruited to complete the TSST. Salivary hormone samples were taken just prior to and 20 min post-stressor, and participants were interviewed with the Psychopathy Checklist-Youth Version. Variables quantifying the amount of time at the present facility prior to the date of testing and number of commitments in juvenile facilities were also collected. Correlational analyses indicated that only number of incarcerations was related to blunted cortisol. Hierarchical Linear Modeling revealed that time incarcerated and number of commitments were related to a blunted cortisol response among responders and declining cortisol reactivity among nonresponders, respectively. Controlling for time incarcerated, psychopathic traits were significantly related to cortisol decline in response to the stressor among nonresponders, but were not related to blunted cortisol among responders. Results of this project highlight the potential biological effects of prolonged and repeated incarcerations, and extend our understanding about the relationship between psychopathic traits and cortisol reactivity in an incarcerated sample.

Examining transactional influences between reading achievement and antisocially-behaving friends.

The association between poorer academic outcomes and having antisocial friends is reliably demonstrated yet not well understood. Genetically sensitive designs uniquely allow for measuring genetic vulnerabilities and/or environmental risk in the association of antisocial friend behavior and poor school achievement, allowing for a better understanding of the nature of the association. This study included 233 pairs of twins from the Florida Twin Project on Reading. First, the role of antisocial friends as an environmental moderator of reading comprehension was examined. Antisocial friends significantly moderated the nonshared environmental variance in reading comprehension, with increased variation at lower levels of association with antisocial friends, with niche-picking indicated. Second, the role of reading comprehension as an environmental moderator of antisocial friends was examined. Reading comprehension significantly moderated the nonshared environmental variance in associating with antisocial friends, with increased variance at lower levels of reading comprehension and indication that common genetic influences contributed to higher reading achievement and better-behaved friends. In total, these results suggested reciprocal influences between reading achievement and antisocially-behaving friends. The impact of antisocial friends appeared to be limited in the extent to which they can undermine reading achievement, and high reading achievement appeared to support less association with antisocial friends.