A genetically informative analysis of the association between dyadic adjustment, depressive symptoms, and anxiety symptoms

BACKGROUND

Prior research has found a reliable and robust association between poor dyadic (e.g., marital) adjustment and depression and anxiety. However, it is possible that this association may be due, at least in part, to confounding variables (i.e., variables that are causally associated both with marital adjustment and psychopathology and could account for their covariation). The present study was conducted using a genetically informative sample of twins to examine the association between dyadic adjustment and symptoms of depression and anxiety, accounting for unmeasured genetic and shared environmental confounds.

METHODS

A Swedish sample of monozygotic and dizygotic twins (218 female twin pairs and 321 male twin pairs) and their spouse or long-term partner completed self-report measures of dyadic adjustment, depressive symptoms, and anxiety symptoms.

RESULTS

Results suggest that dyadic adjustment was significantly and negatively associated with depressive symptoms and anxiety symptoms in twins, and nonshared environmental influences largely accounted for this association. Furthermore, results obtained from partners' reports of dyadic adjustment were largely consistent with those obtained from twins' reports, suggesting that results were not a function of shared method variance.

LIMITATIONS

Longitudinal research in genetically informative samples would provide a stronger test of the causal association between dyadic adjustment and psychopathology.

CONCLUSIONS

The pattern of findings suggest that common nonshared environmental influences, such as partners' characteristics, may lead to poorer dyadic adjustment and depression and anxiety. Therefore, couple-based interventions that improve dyadic adjustment may be effective in preventing and treating psychopathology in relationship partners.

Contributions of mothers' and fathers' parenting to children's self-regulation: Evidence from an adoption study

The origins of top-down self-regulation are attributed to genetic and socialization factors as evidenced by high heritability estimates from twin studies and the influential role of parenting. However, recent evidence suggests that parenting behavior itself is affected by parents' own top-down self-regulation. Because children's top-down self-regulation is influenced by genetic factors and parenting is influenced by top-down self-regulation, the effects of parenting on children's top-down self-regulation identified in prior studies may partially reflect passive gene-environment correlation. The goal of this study was to examine parenting influences on children's top-down self-regulation using a longitudinal, adoption-at-birth design, a method of identifying parenting influences that are independent of the role of shared genetic influences on children's characteristics because adoptive parents are genetically unrelated to their adopted child. Participants (N = 361) included adoptive families and biological mothers of adopted children. Adoptive mothers' and fathers' harsh/negative parenting were assessed when children were 27 months of age and biological mothers' top-down self-regulation was assessed when children were 54 months of age. Adopted children's top-down self-regulation was assessed when they were 54 and 72 months of age. Results, accounting for child gender, biological mother top-down self-regulation, and the potential evocative effects of adopted child anger, provide evidence that inherited influences and socialization processes uniquely contribute to children's top-down self-regulation. Furthermore, findings demonstrate the importance of both mother's and father's parenting behavior as an influence on young children's top-down self-regulation. The implications of these findings for understanding the complex mechanisms that influence children's top-down self-regulation are discussed.

Additive drug-specific and sex-specific risks associated with co-use of marijuana and tobacco during pregnancy: Evidence from 3 recent developmental cohorts (2003-2015)

BACKGROUND

Methodologic challenges related to the concomitant use (co-use) of substances and changes in policy and potency of marijuana contribute to ongoing uncertainty about risks to fetal neurodevelopment associated with prenatal marijuana use. In this study, we examined two biomarkers of fetal neurodevelopmental risk-birth weight and length of gestation-associated with prenatal marijuana use, independent of tobacco (TOB), alcohol (ALC), other drug use (OTH), and socioeconomic risk (SES), in a pooled sample (N = 1191) derived from 3 recent developmental cohorts (2003-2015) with state-of-the-art substance use measures. We examined differential associations by infant sex, and multiplicative effects associated with co-use of MJ and TOB.

METHODS

Participants were mother-infant dyads with complete data on all study variables derived from Growing Up Healthy (n = 251), Behavior and Mood in Babies and Mothers (Cohorts 1 and 2; n = 315), and the Early Growth and Development Study (N = 625). We estimated direct effects on birth weight and length of gestation associated with MJ, TOB, and co-use (MJ x TOB), using linear regression analysis in the full sample, and in male (n = 654) and female (n = 537) infants, separately.

RESULTS

Mean birth weight and length of gestation were 3277 g (SD = 543) and 37.8 weeks (SD = 2.0), respectively. Rates of prenatal use were as follows: any use, n = 748 (62.8%); MJ use, n = 273 (22.9%); TOB use, n = 608 (51.0%); co-use of MJ and TOB, n = 230 (19.3%); ALC use, n = 464 (39.0%); and OTH use n = 115 (9.7%.) For all infants, unique effects on birth weight were observed for any MJ use [B(SE) = -84.367(38.271), 95% C.I. -159.453 to -9.281, p = .028], any TOB use [B(SE) = -0.99.416(34.418), 95% C.I. -166.942 to -31.889, p = .004], and each cigarette/day in mean TOB use [B(SE) = -12.233(3.427), 95% C.I. -18.995 to -5.510, p < .001]. Additional effects of co-use on birth weight, beyond these drug-specific effects, were not supported. In analyses stratified by sex, while TOB use was associated with lower birth weight in both sexes, MJ use during pregnancy was associated with lower birth weight of male infants [B(SE) = -153.1 (54.20); 95% C.I. -259.5 to -46.7, p = .005], but not female infants [B(SE) = 8.3(53.1), 95% C.I. -96.024 to 112.551, p = .876]. TOB, MJ, and their co-use were not associated with length of gestation.

CONCLUSIONS

In this sample, intrauterine co-exposure to MJ and TOB was associated with an estimated 18% reduction in birth weight not attributable to earlier delivery, exposure to ALC or OTH drugs, nor to maternal SES. We found evidence for greater susceptibility of male fetuses to any prenatal MJ exposure. Examination of dose-dependence in relationships found in this study, using continuous measures of exposure, is an important next step. Finally, we underscore the need to consider (a) the potential moderating influence of fetal sex on exposure-related neurodevelopmental risks; and (b) the importance of quantifying expressions of risk through subtle alterations, rather than dichotomous outcomes.

Examining Morning HPA Axis Activity as a Moderator of Hostile, Over-reactive Parenting on Children's Skills for Success in School

This study examined children's morning HPA axis activation as a moderator of links between hostile, over-reactive parenting at age 4.5 years and children's skills for success in school (higher executive function and literacy, and less externalizing behavior) at age 6. Participants included 361 adoptive families. Parenting was self-reported. HPA axis activation was measured by basal levels in morning cortisol. Executive function and literacy were assessed via standardized tasks. Externalizing behavior was reported by teachers. Results indicated that hostile, over-reactive parenting predicted more externalizing behavior and lower executive functioning regardless of children's morning HPA axis activation. HPA axis activation moderated the effects of hostile, over-reactive parenting on literacy. Among children with moderate to high morning HPA axis activation (approximately 60% of the sample), harsh parenting was linked with lower literacy; children with low morning HPA axis activation exhibited better literacy in the context of more hostile, over-reactive parenting. Yet, across the sample, hostile, over-reactive parenting remained in the low to moderate range, not in the high range. Findings are discussed in the context of considering not only whether children's stress system activation moderates responses to their environments, but also how these processes operate for different developmental outcomes.

Age-Moderation of Genetic and Environmental Contributions to Cognitive Functioning in Mid- and Late-Life for Specific Cognitive Abilities

Age moderation of genetic and environmental contributions to Digits Forward, Digits Backward, Block Design, Symbol Digit, Vocabulary, and Synonyms was investigated in a sample of 14,534 twins aged 26 to 98 years. The Interplay of Genes and Environment across Multiple Studies (IGEMS) consortium contributed the sample, which represents nine studies from three countries (USA, Denmark, and Sweden). Average test performance was lower in successively older age groups for all tests. Significant age moderation of additive genetic, shared environmental, and non-shared environmental variance components was observed, but the pattern varied by test. The genetic contribution to phenotypic variance across age was smaller for both Digit Span tests, greater for Synonyms, and stable for Block Design and Symbol Digit. The non-shared environmental contribution was greater with age for the Digit Span tests and Block Design, while the shared environmental component was small for all tests, often more so with age. Vocabulary showed similar age-moderation patterns as Synonyms, but these effects were nonsignificant. Findings are discussed in the context of theories of cognitive aging.

Naturalistic Experimental Designs as Tools for Understanding the Role of Genes and the Environment in Prevention Research

Before genetic approaches were applied in experimental studies with human populations, they were used by animal and plant breeders to observe, and experimentally manipulate, the role of genes and environment on specific phenotypic or behavioral outcomes. For obvious ethical reasons, the same level of experimental control is not possible in human populations. Nonetheless, there are natural experimental designs in human populations that can serve as logical extensions of the rigorous quantitative genetic experimental designs used by animal and plant researchers. Applying concepts such as cross-fostering and common garden rearing approaches from the life science discipline, we describe human designs that can serve as naturalistic proxies for the controlled quantitative genetic experiments facilitated in life sciences research. We present the prevention relevance of three such human designs: (1) children adopted at birth by parents to whom they are not genetically related (common garden approach); (2) sibling designs where one sibling is reared from birth with unrelated adoptive parents and the other sibling is reared from birth by the biological mother of the sibling pair (cross-fostering approach); and (3) in vitro fertilization designs, including egg donation, sperm donation, embryo donation, and surrogacy (prenatal cross-fostering approach). Each of these designs allows for differentiation of the effects of the prenatal and/or postnatal rearing environment from effects of genes shared between parent and child in naturalistic ways that can inform prevention efforts. Example findings from each design type are provided and conclusions drawn about the relevance of naturalistic genetic designs to prevention science.

The Impact of Variation in Twin Relatedness on Estimates of Heritability and Environmental Influences

By taking advantage of the natural variation in genetic relatedness among identical (monozygotic: MZ) and fraternal (dizygotic: DZ) twins, twin studies are able to estimate genetic and environmental contributions to complex human behaviors. Recently concerns have been raised about the accuracy of twin studies in light of findings of genetic and epigenetic changes in twins. One of the concerns raised is that MZ twins are not 100% genetically and epigenetically similar because they show variations in their genomes and epigenomes leading to inaccurate estimates of heritability. This article presents findings from a simulation study that examined the degree of bias in estimates of heritability and environmentality when the genetic and epigenetic similarity of MZ twins differs from 1.00 and when the genetic and epigenetic similarity of DZ twins differs from 0.50. The findings suggest that in the standard biometric model when MZ or DZ twin similarity differs from 1.00 or 0.50, respectively, the variance that should be attributed to genetic influences is instead attributed to nonshared environmental influences, thus deflating the estimates of genetic influences and inflating the estimates of nonshared environmental influences. Although estimates of genetic and nonshared environmental influences from the standard biometric model were found to deviate from "true" values, the bias was usually smaller than 10% points indicating that the interpretations of findings from previous twin studies are mostly correct.

Gene-environment interplay in depressive symptoms: moderation by age, sex, and physical illness

BACKGROUND

Numerous factors influence late-life depressive symptoms in adults, many not thoroughly characterized. We addressed whether genetic and environmental influences on depressive symptoms differed by age, sex, and physical illness.

METHOD

The analysis sample included 24 436 twins aged 40-90 years drawn from the Interplay of Genes and Environment across Multiple Studies (IGEMS) Consortium. Biometric analyses tested age, sex, and physical illness moderation of genetic and environmental variance in depressive symptoms.

RESULTS

Women reported greater depressive symptoms than men. After age 60, there was an accelerating increase in depressive symptom scores with age, but this did not appreciably affect genetic and environmental variances. Overlap in genetic influences between physical illness and depressive symptoms was greater in men than in women. Additionally, in men extent of overlap was greater with worse physical illness (the genetic correlation ranged from near 0.00 for the least physical illness to nearly 0.60 with physical illness 2 s.d. above the mean). For men and women, the same environmental factors that influenced depressive symptoms also influenced physical illness.

CONCLUSIONS

Findings suggested that genetic factors play a larger part in the association between depressive symptoms and physical illness for men than for women. For both sexes, across all ages, physical illness may similarly trigger social and health limitations that contribute to depressive symptoms.

Maternal depression and parenting in early childhood: Contextual influence of marital quality and social support in two samples

Marital quality and social support satisfaction were tested as moderators of the association between maternal depressive symptoms and parenting during early childhood (18-36 months) among 2 large, divergent, longitudinal samples (n = 526; n = 570). Unexpectedly, in both samples the association between maternal depressive symptoms and reduced parenting quality was strongest in the context of high marital quality and high social support, and largely nonsignificant in the context of low marital quality and low social support. Possible explanations for these surprising findings are discussed. Results point to the importance of accounting for factors in the broader family context in predicting the association between depressive symptoms and maternal parenting. (PsycINFO Database Record

Associations between the parent-child relationship and adolescent self-worth: a genetically informed study of twin parents and their adolescent children

BACKGROUND

Low self-worth during adolescence predicts a range of emotional and behavioural problems. As such, identifying potential sources of influence on self-worth is important. Aspects of the parent-child relationship are often associated with adolescent self-worth but to date it is unclear whether such associations may be attributable to familial confounding (e.g. genetic relatedness). We set out to clarify the nature of relationships between parental expressed affection and adolescent self-worth, and parent-child closeness and adolescent self-worth.

METHODS

We used data from the Twin and Offspring Study in Sweden, a children-of-twins sample comprising 909 adult twin pairs with adolescent children. Using these data we were able to apply structural equation models with which we could examine whether associations remained after accounting for genetic transmission.

RESULTS

Results demonstrated that parent-child closeness and parental-expressed affection were both phenotypically associated with adolescent self-worth. Associations could not be attributed to genetic relatedness between parent and child.

CONCLUSIONS

Parent-child closeness and parental affection are associated with adolescent self-worth above and beyond effects attributable to genetic relatedness. Data were cross-sectional, so the direction of effects cannot be confirmed but findings support the notion that positive parent-child relationships increase adolescent self-worth.

Heritable temperament pathways to early callous-unemotional behaviour

BACKGROUND

Early callous-unemotional behaviours identify children at risk for antisocial behaviour. Recent work suggests that the high heritability of callous-unemotional behaviours is qualified by interactions with positive parenting.

AIMS

To examine whether heritable temperament dimensions of fearlessness and low affiliative behaviour are associated with early callous-unemotional behaviours and whether parenting moderates these associations.

METHOD

Using an adoption sample (n = 561), we examined pathways from biological mother self-reported fearlessness and affiliative behaviour to child callous-unemotional behaviours via observed child fearlessness and affiliative behaviour, and whether adoptive parent observed positive parenting moderated pathways.

RESULTS

Biological mother fearlessness predicted child callous-unemotional behaviours via earlier child fearlessness. Biological mother low affiliative behaviour predicted child callous-unemotional behaviours, although not via child affiliative behaviours. Adoptive mother positive parenting moderated the fearlessness to callous-unemotional behaviour pathway.

CONCLUSIONS

Heritable fearlessness and low interpersonal affiliation traits contribute to the development of callous-unemotional behaviours. Positive parenting can buffer these risky pathways.

Early inherited risk for anxiety moderates the association between fathers' child-centered parenting and early social inhibition

Studies of the role of the early environment in shaping children's risk for anxiety problems have produced mixed results. It is possible that inconsistencies in previous findings result from a lack of consideration of a putative role for inherited influences moderators on the impact of early experiences. Early inherited influences not only contribute to vulnerabilities for anxiety problems throughout the lifespan, but can also modulate the ways that the early environment impacts child outcomes. In the current study, we tested the effects of child-centered parenting behaviors on putative anxiety risk in young children who differed in levels of inherited vulnerability. We tested this using a parent-offspring adoption design and a sample in which risk for anxiety problems and parenting behaviors were assessed in both mothers and fathers. Inherited influences on anxiety problems were assessed as anxiety symptoms in biological parents. Child-centered parenting was observed in adoptive mothers and fathers when children were 9 months old. Social inhibition, an early temperament marker of anxiety risk, was observed at child ages 9 and 18 months. Inherited influences on anxiety problems moderated the link between paternal child-centered parenting during infancy and social inhibition in toddlerhood. For children whose birth parents reported high levels of anxiety symptoms, greater child-centered parenting in adoptive fathers was related to greater social inhibition 9 months later. For children whose birth parents reported low levels of anxiety symptoms, greater child-centered parenting in adoptive fathers was related to less social inhibition across the same period.

Birth and Adoptive Parent Antisocial Behavior and Parenting: A Study of Evocative Gene-Environment Correlation

Negative parenting is shaped by the genetically influenced characteristics of children (via evocative rGE) and by parental antisocial behavior; however, it is unclear how these factors jointly impact parenting. This study examined the effects of birth parent and adoptive parent antisocial behavior on negative parenting. Participants included 546 families within a prospective adoption study. Adoptive parent antisocial behavior emerged as a small but significant predictor of negative parenting at 18 months and of change in parenting from 18 to 27 months. Birth parent antisocial behavior predicted change in adoptive father's (but not mother's) parenting over time. These findings highlight the role of parent characteristics and suggest that evocative rGE effects on parenting may be small in magnitude in early childhood.

Heritable and Nonheritable Pathways to Early Callous-Unemotional Behaviors

OBJECTIVE

Callous-unemotional behaviors in early childhood signal higher risk for trajectories of antisocial behavior and callous-unemotional traits that culminate in later diagnoses of conduct disorder, antisocial personality disorder, and psychopathy. Studies demonstrate high heritability of callous-unemotional traits, but little research has examined specific heritable pathways to early callous-unemotional behaviors. Studies also indicate that positive parenting protects against the development of callous-unemotional traits, but genetically informed designs have not been used to confirm that these relationships are not the product of gene-environment correlations. In a sample of adopted children and their biological and adoptive mothers, the authors tested novel heritable and nonheritable pathways to preschool callous-unemotional behaviors.

METHOD

In an adoption cohort of 561 families, history of severe antisocial behavior assessed in biological mothers and observations of adoptive mother positive reinforcement at 18 months were examined as predictors of callous-unemotional behaviors at 27 months.

RESULTS

Despite limited or no contact with offspring, biological mother antisocial behavior predicted early callous-unemotional behaviors. Adoptive mother positive reinforcement protected against early callous-unemotional behaviors. High levels of adoptive mother positive reinforcement buffered the effects of heritable risk for callous-unemotional behaviors posed by biological mother antisocial behavior.

CONCLUSIONS

The findings elucidate heritable and nonheritable pathways to early callous-unemotional behaviors. The results provide a specific heritable pathway to callous-unemotional behaviors and compelling evidence that parenting is an important nonheritable factor in the development of callous-unemotional behaviors. The finding that positive reinforcement buffered heritable risk for callous-unemotional behaviors has important translational implications for the prevention of trajectories to serious antisocial behavior.

Infant patterns of reactivity to tactile stimulation during parent-child interaction

Touch is the primary modality infants use to engage with the world; atypical responses to tactile stimuli may indicate risk for disordered outcomes. The current study examined infants' responses to tactile stimulation within parent-child interaction, adding to prior knowledge based on parent report. Nine-month-old infants (N=497) were observed while parents painted and pressed infants' hands and feet to paper to make designs. Positive and negative affect and gazing away, exploring, and resistance behaviors were coded. Latent Class Analysis of observed behaviors yielded four tactile response patterns partially consistent with current nosology for sensory processing patterns: Low Reactive, Sensory Overreactive, Sensory Seeking, and Mixed Over/Underreactive. To evaluate whether patterns made valid distinctions among infants, latent classes were examined in relation to parent-reported temperament. Infants in the Mixed Over/Underreactive class were rated higher in distress to limitations and activity level than other infants. Sensory processing patterns observed in parent-child interaction are consistent with those identified by parent-report and may be used in future research to elucidate relations with temperament and typical and atypical development.

Genetic and environmental influences on teacher ratings of the Child Behavior Checklist

The knowledge we have of childhood and adolescent behaviour is, to some extent, a function of the unique perspective of the rater. Although many behavioural genetics studies have used parent and child self-reports in their assessments of child and adolescent adjustment, few have included teacher ratings of behaviour. It is possible that genetic and environmental contributions to teacher reports are different from those using parent and self-reports. The present study examined genetic and environmental influences on six subscales of the Child Behavior Checklist Teacher Report Form (CBC-TRF) using a normative sample of adolescents. The sample consisted of 373 same-sex twin and sibling pairs of varying degrees of genetic relatedness participating in the Nonshared Environment in Adolescent project (NEAD). For all of the CBC subscales, except attention problems and social problems, nonshared environmental influence was the most important source of variance. Additive genetic factors were of moderate importance for externalising behaviours, whereas nonadditive genetic factors contributed to the anxious/depressed, attention problems, withdrawn, and social problems subscales. For none of the constructs was shared environment a significant influence. Three alternative models testing for contrast effects, differences in twin and nontwin siblings, and differences in nondivorced and stepfamilies were examined. In most cases, the best-fitting model was a model that did not include any of these effects, suggesting that these factors do not critically affect the basic model. However, some of the patterns of correlations and parameter estimates were unusual and may warrant future investigation.

Combining Stress Exposure and Stress Generation: Does Neuroticism Alter the Dynamic Interplay of Stress, Depression, and Anxiety Following Job Loss?

OBJECTIVE

Emerging models of stress point to a dynamic formulation where stressors and internalizing symptoms reciprocally influence each other. This study tested whether this dynamic interplay is the result of a general internalizing process underlying both depression and anxiety, and whether it varies with neuroticism.

METHOD

A total of 426 adults (51% female; 47% White, 42% African American) were assessed five times over 6 months following loss of employment, using repeated measurements of stressors, depression, anxiety, and neuroticism.

RESULTS

Latent growth across 6 months and multilevel cross-lagged regressions across 6 weeks supported the hypothesis that stressors and internalizing symptoms have reciprocal effects after job loss. Findings for unique variation in depression paralleled those for general internalizing, whereas few findings emerged for general or social anxiety after controlling for internalizing. Neuroticism strengthened the association of change in stressors with change in symptoms across 6 months. Those with high neuroticism showed less reduction in internalizing following reemployment and were less likely to be reemployed when starting with higher internalizing.

CONCLUSIONS

The moderated reciprocal effects model helps account for onset, maintenance, and resolution of symptoms following job loss. We speculate that these findings may be due in part to differential emotion regulation and reductions in motivation.

Passive rGE or Developmental Gene-Environment Cascade? An Investigation of the Role of Xenobiotic Metabolism Genes in the Association Between Smoke Exposure During Pregnancy and Child Birth Weight

There is considerable evidence that smoke exposure during pregnancy (SDP) environmentally influences birth weight after controlling for genetic influences and maternal characteristics. However, maternal smoking during pregnancy-the behavior that leads to smoke exposure during pregnancy-is also genetically-influenced, indicating the potential role of passive gene-environment correlation. An alternative to passive gene-SDP correlation is a cascading effect whereby maternal and child genetic influences are causally linked to prenatal exposures, which then have an 'environmental' effect on the development of the child's biology and behavior. We describe and demonstrate a conceptual framework for disentangling passive rGE from this cascading GE effect using a systems-based polygenic scoring approach comprised of genes shown to be important in the xenobiotic (substances foreign to the body) metabolism pathway. Data were drawn from 5044 families from the Avon Longitudinal Study of Parents and Children with information on maternal SDP, birth weight, and genetic polymorphisms in the xenobiotic pathway. Within a k-fold cross-validation approach (k = 5), we created weighted maternal and child polygenic scores using 18 polymorphisms from 10 genes that have been implicated in the xenobiotic metabolism pathway. Mothers and children shared variation in xenobiotic metabolism genes. Amongst mothers who smoked during pregnancy, neither maternal nor child xenobiotic metabolism polygenic scores were associated with a higher likelihood of smoke exposure during pregnancy, or the severity of smoke exposure during pregnancy (and therefore, neither proposed mechanism was supported), or with child birth weight. SDP was consistently associated with lower child birth weight controlling for the polygenic scores, maternal educational attainment, social class, psychiatric problems, and age. Limitations of the study design and the potential of the framework using other designs are discussed.

The Importance of the Prenatal Environment in Behavioral Genetics: Introduction to Special Issue

We introduce and discuss a special issue on prenatal factors in genetics research, that includes 14 papers ranging from studies on chorionicity, smoking during pregnancy, and more general prenatal risks to papers about theory, methods and measurement. There are two review papers, one focused on chorioncity and the second on pre- and perinatal ischemia-hypoxia, that help to frame the state of research in these areas with a focus on the relevance across multiple fields of study. Taken together, these papers clearly demonstrate the importance of considering prenatal environment influences on functioning in offspring across the lifespan while also underscoring the importance of using genetically informed designs as a means to clarify causality.

The Perinatal Risk Index: Early Risks Experienced by Domestic Adoptees in the United States

We aimed to assess comprehensively the prevalence of perinatal risks experienced by a potentially high-risk yet understudied population of children domestically adopted in the United States. Data are from participant report and medical records from mothers (n = 580) who completed a domestic adoption placement with nonrelatives at or near birth (Mean placement age = 7 days). We describe a comprehensive measure of perinatal risks, including divergences from previous assessment tools and the incorporation of multiple reporters, and report the prevalence of various types of perinatal risks. The prevalence of each specific risk factor was generally low, although several risks were more prevalent in this sample than estimates from nationally representative publicly available data. Nearly the entire sample (99%) experienced some type of risk exposure. Birth mothers who placed their children for adoption domestically in the US experience higher levels of perinatal risks than the national average, but not for all specific types of risk. Thus, the developmental trajectories of children adopted domestically may systematically differ from the general population to the extent that these specific perinatal risks impact development.

Marital Hostility, Hostile Parenting, and Child Aggression: Associations from Toddlerhood to School Age

OBJECTIVE

The spillover hypothesis suggests that childhood aggression results from spillover of interparental conflict to poor parenting, which promotes aggressive child behavior. This study was designed to examine the spillover hypothesis in non-genetically related parent-child dyads from the toddler period through age 6 years.

METHOD

A sample of 361 sets of children, adoptive parents, and birth parents from the Early Growth and Development Study (EGDS) was assessed from child age 9 months to 6 years on measures of adoptive parent financial strain, antisocial traits, marital hostility, hostile parenting, and child aggression. Structural equation modeling was used to examine links from financial strain, parent antisocial traits, and marital hostility in infancy and toddlerhood to hostile parenting and child aggression at ages 4.5 and 6 years.

RESULTS

Spillover of marital conflict from child age 18 to 27 months was associated with more parental hostility in mothers and fathers at 27 months. In turn, adoptive fathers' parental hostility, but not mothers', was associated with aggression in children at age 4.5 years. However, there was no significant spillover from hostile parenting at 4.5 years to child aggression at 6 years. Birth mother antisocial traits were unassociated with child aggression.

CONCLUSION

This study is the first to examine spillover of marital hostility to parenting to child aggression from toddlerhood through age 6 years in an adoption design, highlighting the impact of these environmental factors from the toddler to preschool period. The findings support the potential benefit of early identification of marital hostility.

Adolescent age moderates genetic and environmental influences on parent-adolescent positivity and negativity: Implications for genotype-environment correlation

We examined how genotype-environment correlation processes differ as a function of adolescent age. We tested whether adolescent age moderates genetic and environmental influences on positivity and negativity in mother-adolescent and father-adolescent relationships using parallel samples of twin parents from the Twin and Offspring Study in Sweden and twin/sibling adolescents from the Nonshared Environment in Adolescent Development Study. We inferred differences in the role of passive and nonpassive genotype-environment correlation based on biometric moderation findings. The findings indicated that nonpassive gene-environment correlation played a stronger role for positivity in mother- and father-adolescent relationships in families with older adolescents than in families with younger adolescents, and that passive gene-environment correlation played a stronger role for positivity in the mother-adolescent relationship in families with younger adolescents than in families with older adolescents. Implications of these findings for the timing and targeting of interventions on family relationships are discussed.