Reactive and control processes in the development of internalizing and externalizing problems across early childhood to adolescence.

Reactive and control processes - e.g., negative emotionality and immediacy preference - may predict distinct psychopathology trajectories. However, externalizing and internalizing problems change in behavioral manifestation across development and across contexts, thus necessitating the use of different measures and informants across ages. This is the first study that created developmental scales for both internalizing and externalizing problems by putting scores from different informants and measures onto the same scale to examine temperament facets as risk factors. Multidimensional linking allowed us to examine trajectories of internalizing and externalizing problems from ages 2 to 15 years (N = 1,364) using near-annual ratings by mothers, fathers, teachers, other caregivers, and self report. We examined reactive and control processes in early childhood as predictors of the trajectories and as predictors of general versus specific psychopathology in adolescence. Negative emotionality at age 4 predicted general psychopathology and unique externalizing problems at age 15. Wait times on an immediacy preference task at age 4 were negatively associated with age 15 general psychopathology, and positively associated with unique internalizing problems. Findings demonstrate the value of developmental scaling for examining development of psychopathology across a lengthy developmental span and the importance of considering reactive and control processes in development of psychopathology.

The double jeopardy of low family income and negative emotionality: The family stress model revisited.

The family stress model has, for decades, guided empirical work linking poverty with increased risk of child social-emotional dysfunction. The present study extends this line of work by examining whether child negative emotionality moderates associations between family income, family stress (maternal distress, parental locus of control, and relationship dissatisfaction), and later externalizing and internalizing behavior problems. In a longitudinal population-based sample (n ~ 80,000) of Norwegian children followed from birth through age five (The Norwegian Mother, Father, and Child Cohort Study; MoBa), we examined whether high (vs. moderate or low) negative emotionality families would display: (a) compounding stress (i.e., particularly strong associations between low family income and family stress), (b) diathesis-stress (i.e., particularly strong associations between family stress and behavior problems), or (c) double jeopardy (i.e., both compounding stress and diathesis-stress moderating effects). Negative emotionality significantly moderated the association between family income and behavior problems in a manner most consistent with double jeopardy. As a result, compared with children with moderate/low negative emotionality, the family income-behavior problems association was two to three times larger for those with higher negative emotionality. These findings underscore the active role children may play in family processes that link low family income with behavior problems.

Comparing Transdiagnostic Risk Factors: Predicting Emergence of Significant Depressive, Anxiety, and Substance Abuse Symptoms Among Juvenile Delinquents.

In a 7-year 11-wave study of low-SES adolescents (N = 856, age = 15.98), we compared multiple well-established transdiagnostic risk factors as predictors of first incidence of significant depressive, anxiety, and substance abuse symptoms across the transition from adolescence to adulthood. Risk factors included negative emotionality, emotion regulation ability, social support, gender, history of trauma, parental histories of substance abuse, parental mental health, and socioeconomic status. Machine learning models revealed that negative emotionality was the most important predictor of both depression and anxiety, and emotion regulation ability was the most important predictor of future significant substance abuse. These findings highlight the critical role that dysregulated emotion may play in the development of some of the most prevalent forms of mental illness.

Research Review: A systematic review and meta-analysis of infant and toddler temperament as predictors of childhood attention-deficit/hyperactivity disorder.

BACKGROUND: Attention-deficit/hyperactivity disorder (ADHD) is a common neurodevelopmental disorder with onset as early as preschool and impairment across the lifespan. Temperament factors, specifically those that theoretically map onto ADHD symptoms, may be early markers of risk for developing later childhood ADHD that could be identifiable in infancy or toddlerhood. This meta-analysis examined the associations between these early temperamental factors and later symptoms and diagnosis of ADHD and mapped early temperament constructs onto the three ADHD symptom dimensions. METHODS: A systemic review of the literature was conducted to identify prospective longitudinal studies that included theoretically relevant temperament constructs (sustained attention, activity level, inhibition, and negative emotionality) examined from birth to 36 months old and ADHD (symptoms or diagnosis) in preschool or childhood. The association between each temperament construct and ADHD outcomes was examined using pooled standardized estimates in meta-analyses. RESULTS: Forty-eight articles (n = 112,716 infants/toddlers) prospectively examined temperament and the relation to childhood ADHD symptoms or diagnosis. Activity level (k = 18) in infancy and toddlerhood was moderately associated with childhood ADHD (r = .39, CI = 0.27, 0.51, p < .001). Moderate effect sizes were also observed for sustained attention (k = 9; r = -.28, CI = -0.42, -0.12, p < .001) and negative emotionality (k = 33; r = .25, CI = 0.16, 0.34, p < .001) with ADHD. The specificity of each temperament construct for later ADHD symptom dimensions was such that activity level and negative emotionality were predictive of all three symptom dimensions (i.e., inattention, hyperactivity/impulsivity, and combined), whereas sustained attention was only associated with combined symptoms. CONCLUSIONS: Infant and toddler temperament is an early risk factor for the development of childhood ADHD that could be utilized for early intervention identification. Yet, this systematic review found that relatively few prospective longitudinal studies have examined sustained attention (k = 9) and inhibition (k = 15) in infancy and toddlerhood in relation to later ADHD highlighting the need for further research.

The longitudinal association between infant negative emotionality, childhood maltreatment, and ADHD symptoms: A secondary analysis of data from the Fragile Families and Child Wellbeing Study.

BACKGROUND: Infant temperament predicts harsh parenting, and attention deficit/ hyperactivity disorder (ADHD) symptoms. Moreover, childhood maltreatment has consistently been associated with later ADHD symptoms. We hypothesized that infant negative emotionality predicted both ADHD symptoms and maltreatment, and that there was a bidirectional association between maltreatment experiences and ADHD symptoms. METHODS: The study used secondary data from the longitudinal Fragile Families and Child Wellbeing Study (N = 2860). A structural equation model was conducted, using maximum likelihood with robust standard errors. Infant negative emotionality acted as a predictor. Outcome variables were childhood maltreatment and ADHD symptoms at ages 5 and 9. RESULTS: The model demonstrated good fit (root-mean-square error of approximation = .02, comparative fit index = .99, Tucker-Lewis index = .96). Infant negative emotionality positively predicted childhood maltreatment at ages 5 and 9, and ADHD symptoms at age 5. Age 5 maltreatment/ADHD symptoms predicted age 9 ADHD symptoms/maltreatment. Additionally, both childhood maltreatment and ADHD symptoms at age 5 mediated the association between negative emotionality and childhood maltreatment/ADHD symptoms at age 9. CONCLUSIONS: Given the bidirectional relationship between ADHD and experiences of maltreatment, it is vital to identify early shared risk factors to prevent negative downstream effects and support families at risk. Our study showed that infant negative emotionality, poses one of these risk factors.

Negative emotionality as a candidate mediating mechanism linking prenatal maternal mood problems and offspring internalizing behaviour.

Negative emotionality (NE) was evaluated as a candidate mechanism linking prenatal maternal affective symptoms and offspring internalizing problems during the preschool/early school age period. The participants were 335 mother-infant dyads from the Maternal Adversity, Vulnerability and Neurodevelopment project. A Confirmatory Bifactor Analysis (CFA) based on self-report measures of prenatal depression and pregnancy-specific anxiety generated a general factor representing overlapping symptoms of prenatal maternal psychopathology and four distinct symptom factors representing pregnancy-specific anxiety, negative affect, anhedonia and somatization. NE was rated by the mother at 18 and 36 months. CFA based on measures of father, mother, child-rated measures and a semistructured interview generated a general internalizing factor representing overlapping symptoms of child internalizing psychopathology accounting for the unique contribution of each informant. Path analyses revealed significant relationships among the general maternal affective psychopathology, the pregnancy- specific anxiety, and the child internalizing factors. Child NE mediated only the relationship between pregnancy-specific anxiety and the child internalizing factors. We highlighted the conditions in which prenatal maternal affective symptoms predicts child internalizing problems emerging early in development, including consideration of different mechanistic pathways for different maternal prenatal symptom presentations and child temperament.

Re-considering the Role of Sleep Hygiene Behaviours in Sleep: Associations Between Sleep Hygiene, Perceptions and Sleep.

BACKGROUND: Sleep hygiene behaviours are a suggested set of behaviours people can engage in to improve sleep. However, there are numerous issues relating to the measurement of sleep hygiene, primarily, the lack of consensus as to which behaviours impact sleep and should therefore be included in scales. METHOD: Cross-sectional correlational methods were used to assess the association between sleep quality, a highly inclusive range of sleep hygiene behaviours, and individual perceptions of those behaviours in a non-clinical sample of 300 participants. RESULTS: Of the 35 sleep hygiene behaviours assessed, 18 were independently associated with sleep quality. Post-hoc factor analysis revealed that behaviours clustered together across four factors. A 'routine' factor included behaviours such as going to bed and waking up at the same time each night, and were important predictors of sleep quality, as were behaviours belonging to the 'perseverative cognition' and 'negative emotionality' factor. Other behaviours related to physiological processes like exposure to sunlight during the day and going to bed hungry were also significantly associated with sleep. Negative perceptions moderated the relationship between daytime exposure to sunlight and sleep. CONCLUSIONS: Although certain behaviours were significantly related to sleep, almost half were not, supporting the need to examine the association between sleep and behaviours used for sleep hygiene recommendations more critically. Reframing sleep hygiene recommendations into a condensed set of shared underlying mechanisms may be of benefit for the development of sleep hygiene scales and interventions in non-clinical populations.

Dysregulated Emotion and Trying Substances in Childhood: Insights from a Large Nationally Representative Cohort Study.

OBJECTIVE: Transdiagnostic perspectives on the shared origins of mental illness posit that dysregulated emotion may represent a key driving force behind multiple forms of psychopathology, including substance use disorders. The present study examined whether a link between dysregulated emotion and trying illicit substances could be observed in childhood. METHOD: In a large (N = 7,418) nationally representative sample of children (Mage = 9.9), individual differences in emotion dysregulation were indexed using child and parent reports of frequency of children's emotional outbursts, as well as children's performance on the emotional N-Back task. Two latent variables, derived from either parental/child-report or performance-based indicators, were evaluated as predictors of having ever tried alcohol, tobacco, or marijuana. RESULTS: Results showed that reports of dysregulated emotion were linked to a greater likelihood of trying both alcohol and tobacco products. These findings were also present when controlling for individual differences in executive control and socioeconomic status. CONCLUSIONS: These results suggest that well-established links between dysregulated negative emotion and substance use may emerge as early as in childhood and also suggest that children who experience excessive episodes of uncontrollable negative emotion may be at greater risk for trying substances early in life.

Effortful Control Moderates the Relation Between Negative Emotionality and Child Anxiety and Depressive Symptom Severity in Children with Anxiety Disorders.

The present study investigated the interactive effect of reactive (negative emotionality) and regulatory (effortful control) aspects of temperament in the prediction of child anxiety and depressive symptoms. Clinically anxious children and their mothers completed a battery of questionnaires that included self- and mother-ratings of child effortful control, negative emotionality, anxiety, and depressive symptoms. Multiple regression analyses were conducted to examine the moderating effect of effortful control on the relation between negative emotionality and child anxiety and depressive symptom severity. The interaction between negative emotionality and effortful control was statistically significant and simple slopes revealed that as effortful control increased, the relationship between negative emotionality and anxiety and depressive symptoms weakened. Among anxious children high in negative emotionality, greater effortful control was related to less severe anxiety and depressive symptoms. Future work should evaluate whether targeting effortful control leads to reductions in internalizing symptoms among clinically anxious youth.

Development of negative and positive emotionality in irritable and nonirritable neonates.

OBJECTIVE: The current study compares the development of negative and positive emotionality of irritable and nonirritable neonates. BACKGROUND: Research indicates that the first few months of life are marked by decreases in negative emotionality and increases in positive emotionality. METHODS: The Neonatal Behavioural Assessment Scale (NBAS) was administered twice to 111 neonates at 3 and 4 weeks of age to select a sample of irritable neonates and a comparison group of nonirritable neonates. Mothers completed assessments of negative and positive emotionality at 1, 2, 4, and 9 months of age. RESULTS: Both irritable and nonirritable neonates demonstrate a significant decrease in frustration and a significant increase in positive emotionality from 2 to 4 months of age. Irritable neonates also demonstrate a significant decrease in negative emotionality from 4 to 9 months of age. Both irritable and nonirritable neonates demonstrate considerable stability in negative and positive emotionality. CONCLUSION: Implications of these results for parent education and early intervention are discussed.

Anxiety-Related Frontocortical Activity Is Associated With Dampened Stressor Reactivity in the Real World.

Negative affect is a fundamental dimension of human emotion. When extreme, it contributes to a variety of adverse outcomes, from physical and mental illness to divorce and premature death. Mechanistic work in animals and neuroimaging research in humans and monkeys have begun to reveal the broad contours of the neural circuits governing negative affect, but the relevance of these discoveries to everyday distress remains incompletely understood. Here, we used a combination of approaches-including neuroimaging assays of threat anticipation and emotional-face perception and more than 10,000 momentary assessments of emotional experience-to demonstrate that individuals who showed greater activation in a cingulo-opercular circuit during an anxiety-eliciting laboratory paradigm experienced lower levels of stressor-dependent distress in their daily lives (ns = 202-208 university students). Extended amygdala activation was not significantly related to momentary negative affect. These observations provide a framework for understanding the neurobiology of negative affect in the laboratory and in the real world.

Examination of developmental pathways from preschool temperament to early adolescent ADHD symptoms through initial responsiveness to reward.

To identify sources of phenotypic heterogeneity in attention-deficit/hyperactivity disorder (ADHD) accounting for diversity in developmental/ pathogenic pathways, we examined, in a large sample of youth (N = 354), (a) associations between observed temperamental emotionality at age 3, an electrocortical index (i.e., reward positivity [RewP]) of initial responsiveness to reward at age 9, and ADHD symptoms at age 12, and (b) whether the association between emotionality and ADHD symptoms is mediated by initial responsiveness to reward. Bivariate analyses indicated greater positive emotionality (PE) was associated with enhanced RewP, lower age-9ADHD and lower age-12 inattention (IA). Negative emotionality (NE) was not associated with RewP or ADHD. Mediation analyses revealed the association between PE and hyperactivity/impulsivity (H/I) was mediated by RewP; enhanced RewP was associated with greater H/I. Greater PE was associated with enhanced RewP at a trend level. These effects held accounting for age-9 ADHD, age-12 IA and age-12 oppositional defiant and conduct disorder symptoms. As such, preschool emotionality is associated with adolescent ADHD-H/I symptoms through late childhood initial responsiveness to reward. These relations indicate that individual differences in emotionality and reward responsiveness may be informative for personalizing ADHD interventions.

Negative Emotionality and Internalizing Behaviors in Preschool Children: Moderating Role of Inhibitory Control.

Negative emotionality in childhood is typically positively associated with internalizing behaviors, whereas inhibitory control is negatively associated with internalizing behaviors. Recent work, however, has also found that inhibitory control paradoxically increases risk for internalizing behaviors in the context of some reactive temperamental styles. The purpose of the present study was to examine whether inhibitory control moderated the association between negative emotionality and prospective internalizing behaviors in typically developing preschoolers (N = 104, 51 girls, Mage = 3.46 years, SDage = 0.19). We found that negative emotionality at T1 was only positively associated with internalizing behaviors at T2 in preschoolers with relatively higher inhibitory control. Our results suggest that relatively high levels of inhibitory control may be less adaptive for children who also have relatively high levels of negative emotionality. Findings are discussed in the context of cognitive overcontrol in understanding risk for internalizing behaviors before formal school entry.

Serotonin transporter gene methylation and emotional regulation in preschool children born preterm: A longitudinal evaluation of the role of negative emotionality in infancy.

The aim of the study was to assess the contribution of negative emotionality at 3 months (T1) and serotonin transporter gene (SLC6A4) DNA methylation at 4.5 years of age (T2) to emotion regulation in pre-schoolers born very preterm and full-term. Forty one children (n = 21 born very preterm, n = 20 born full-term) participated in the study. Fretful behavior was assessed at T1 in response to the Face-to-FaceStill-Face (FFSF) paradigm. At T2, SLC6A4 DNA methylation was analyzed and emotion regulation was assessed using an observational procedure (i.e., the Pre-schooler Regulation of Emotional Stress, PRES). The very preterm group displayed higher emotion dysregulation during the PRES Reactivity phase than the full-term group. Higher levels of fretful behavior at 3 months were associated with greater emotional distress only for very preterm children with higher methylation at T2. No significant associations emerged in the full-term group. Despite current findings cannot be generalized owing to the relatively small sample size, this work provides preliminary longitudinal evidence about the link between negative emotionality during infancy, stress-linked epigenetic status at 4.5 years and emotion dysregulation in preschoolers born preterm.

El propósito del estudio fue evaluar la contribución de la emocionalidad negativa a los 3 meses (T1) y la metilación del ADN en el gen transportador de la serotonina (SLC6A4) a los 4 años y medio de edad (T2) a la regulación de la emoción en prescolares nacidos muy antes de la gestación completa o de gestación completa. Cuarenta y un niños (n = 21 nacidos muy antes de la gestación completa, n = 20 nacidos de gestación completa) participaron en el estudio. El comportamiento irritable se evaluó a T1 como respuesta al Cara-a-Cara del paradigma de la Cara Inmóvil (FFSF). A T2, se analizó la metilación de ADN SLC6A4 y se evaluó la regulación de la emoción usando un procedimiento de observación (v.g. La Regulación del Estrés Emocional del Prescolar, PRES). El grupo nacido muy antes de la gestación completa mostró una más alta desregulación durante la fase de Reactividad PRES que el grupo nacido de gestación completa. Los niveles más altos de comportamiento irritable a los 3 meses se asociaron con una mayor angustia emocional solamente para los niños nacidos muy antes de la gestación completa con más alta metilación al T2. Ninguna asociación significativa surgió del grupo nacido de gestación completa. A pesar de que los actuales resultados no se pueden generalizar debido al tamaño relativamente pequeño del grupo muestra, este trabajo ofrece aporta evidencia longitudinal preliminar acerca de la conexión entre la emocionalidad negativa durante la infancia, el estado epigenético relacionado con el estrés a los 4 años y medio y la desregulación de la emoción en prescolares nacidos antes de la completa gestación.

Le but de cette étude était d'évaluer la contribution de l'émotivité négative à 3 mois (T1) et du gène vecteur de la sérotonine (SLC6A4) méthylation de l'ADN à l'âge de 4,5 ans (T2) à la régulation de l'émotion chez les enfants d'âge préscolaire nés très prématurés et à plein terme. Quarante et un enfant (n = 21 nés très prématurés, n = 20 nés à plein terme) ont participé à l'étude. Le comportement agité a été évalué au T1 en réponse au paradigme face-à-face visage inexpressif (abrégé FFSF en anglais). Au T2, la méthylation de l'ADN SLC6A4 a été analysée et la régulation de l'émotion a été évaluée en utilisant un protocole d'observation (à savoir, la Régulation du Stress Emotionnel de l'Enfant d'Age Préscolaire, abrégé en anglais PRES). Le groupe très prématuré a fait état d'une dysrégulation de l'émotion plus élevée durant la phase de Réactivité PRES que le groupe né à plein terme. Des niveaux plus élevés de comportement agité à 3 mois étaient liés à une détresse émotionnelle plus grande uniquement pour les enfants très prématurés avec une méthylation plus élevée au T2. Aucune association importante n'a émergé dans le groupe à plein terme. En dépit du fait que les résultats actuels ne peuvent pas être généralisés à cause de la taille relativement petite de l'échantillon, ce travail offre des preuves longitudinales préliminaires sur le lien entre l'émotivité négative durant la petite enfant, le statut épigénétique lié au stress à 4,5 ans et la dysrégulation de l'émotion chez les enfants d'âge préscolaires nés avant terme.

The role of temperament and parenting on anxiety problems among toddlers: Moderating role of parenting and mediating role of attachment.

Anxiety problems are seen as early as 1-2 years of age. Among others, parenting and child temperament are considered as the most important factors affecting anxiety in early childhood. In the current study, the unique roles of parenting (maternal overprotectiveness and warmth) and temperament (behavioral inhibition and negative emotionality), parenting-temperament interactions, and mediating role of ambivalent attachment between behavioral inhibition and anxiety were investigated. One-hundred mother-child (18-36-month-old) dyads participated in this study. Children's anxiety and temperament were measured through mother-reported scales, attachment was measured by observation via home visits, and parenting dimensions were measured via both mother-reported scales and observation. The results revealed that behavioral inhibition and overprotectiveness were positively associated with toddlers' anxiety, whereas there were no significant direct associations of negative emotionality and warmth with anxiety. However, the interaction between behavioral inhibition and warmth predicted toddler's anxiety; that is, if behaviorally inhibited children had mothers who were low on warmth, those children were more likely to exhibit anxiety symptoms compared to children with low behavioral inhibition, whereas anxiety levels did not change for children of warm mothers. Ambivalent attachment mediated the relationship between behavioral inhibition and anxiety. The nature of parent-child interactions is discussed based on toddlerhood anxiety.

Los problemas de ansiedad ya se ven a la temprana edad de 1-2 años. Entre otros, se considera la crianza y el temperamento del niño como los más importantes factores que afectan la ansiedad en la temprana niñez. En el presente estudio se investigaron los roles distintivos de crianza (la sobreprotección y calidez maternas) y temperamento (inhibición de conducta y emocionalidad negativa), las interacciones crianza-temperamento y el rol mediador de la afectividad ambivalente entre inhibición de conducta y ansiedad. Cien díadas madre-niño (18-36 meses de edad) participaron en este estudio. Se midió la ansiedad y el temperamento de los niños por medio de escalas que las madres reportaron, se midió la afectividad por medio de observaciones en visitas a casa, y las dimensiones de crianza se midieron por medio tanto de escalas que las madres reportaron como la observación. Los resultados revelaron que la inhibición de conducta y la sobreprotección se asociaban positivamente con la ansiedad de los pequeños niños, mientras que no se dieron significativas asociaciones directas de la emocionalidad negativa y la calidez con la ansiedad. Sin embargo, la interacción entre la inhibición de conducta y la calidez predijeron la ansiedad de los niños pequeñitos; es decir, si los niños inhibidos en cuanto a conducta tenían madres que estaban a nivel bajo en cuanto a calidez, esos niños estaban más propensos a exhibir síntomas de ansiedad comparados con niños con bajos niveles de inhibición de conducta, mientras que los niveles de ansiedad no cambiaron para niños con madres de cálida acogida. La afectividad ambivalente medió la relación entre la inhibición de conducta y la ansiedad. Se discute la naturaleza de las interacciones progenitor-niño con base en la ansiedad en la primera infancia.

On voit des problèmes d'anxiété aussi tôt qu'à 1-2 ans d'âge. Entre plein d'autres facteurs, le parentage et le tempérament de l'enfant sont estimés être les facteurs les plus importants qui affectent l'anxiété dans la petite enfance. Dans cette étude les rôles uniques du parentage (surprotection maternelle et chaleur maternelle) et le tempérament (inhibition comportementale et émotivité négative), les interactions parentage-tempérament, le rôle médiateur de l'attachement ambivalent entre l'inhibition comportementale et l'anxiété ont fait l'objet des recherches. Cent dyades mère-enfant (18-36 mois d'âge) ont participé à cette étude. L'anxiété et le tempérament des enfants ont été mesurés au travers d'échelles rapportées par la mère et l'attachement a été mesuré par observation au travers de visites à domicile. Les dimensions parentales ont été mesurées au travers d'à la fois les échelles rapportées par la mère et l'observation. Les résultats ont révélé que l'inhibition comportementale et la surprotection sont liées de manière positive à l'anxiété du petit enfant, alors qu'il n'y a pas de lien direct avec l'anxiété pour l'émotivité négative et la chaleur. Cependant l'interaction entre l'inhibition comportementale et la chaleur a prédit l'anxiété du petit enfant. En fait, si les enfants inhibés du point de vue comportemental avaient des mères n'étant pas chaleureuses, ces enfants avaient plus tendance à faire preuve de symptômes d'anxiété que les enfants avec une inhibition comportementale plus basse, alors que les niveaux d'anxiété n'ont pas changé pour les enfants avec des mères chaleureuses. L'attachement ambivalent a médiatisé la relation entre l'inhibition comportementale et l'anxiété. La nature des interactions parent-enfant est discutée basée sur l'anxiété du petit enfant.

Birth Complications and Negative Emotionality Predict Externalizing Behaviors in Young Twins: Moderations with Genetic and Family Risk Factors.

We examined interactions among genetic, biological, and ecological variables predicting externalizing behaviors in preschool and middle childhood. Specifically, we examined prediction of externalizing behaviors from birth complications and negative emotionality, each moderated by genetic risk for aggression and ecological risk factors of insensitive parenting and low family income. At ages 4 and 5 years, 170 twin pairs and 5 triplet sets (N = 355 children) were tested; 166 of those children were tested again at middle childhood (M = 7.9 years). Multilevel linear modeling results showed generally that children at high genetic risk for aggression or from low-income families were likely to have high scores on externalizing, but for children not at high risk, those with increased birth complications or more negative emotionality had high scores on externalizing. This study underscores the importance of considering biological variables as moderated by both genetic and ecological variables as they predict externalizing behaviors across early childhood.

Twin Study of the Relationship between Childhood Negative Emotionality and Hyperactivity/Inattention Problems.

The present study aimed to determine the genetic and environmental etiology of the association between childhood negative emotionality (NE) and hyperactivity/inattention problems (HIP) using South Korean elementary school twins (mean age = 10.19 years, SD = 1.79 years). Telephone interviews were given to mothers of 919 twins (229 monozygotic males: 112 pairs and 5 individuals; 148 dizygotic males: 73 pairs and 2 individuals; 180 monozygotic females: 87 pairs and 6 individuals; 103 dizygotic females: 50 pairs and 3 individuals; 259 opposite-sex dizygotic twins: 127 pairs and 5 individuals) to assess their children's NE and HIP. Consistent with prior studies, the phenotypic correlation between NE and the HIP was moderate (r = .29; 95% CI = .24, .34). Model-fitting analysis revealed that additive genetic and nonshared environmental influences on NE were .45 (95% CI [.34, .54]) and .55 (95% CI [.46, .66]), respectively, and that additive and nonadditive genetic, and nonshared environmental influences on HIP were .08 (95% CI [.03, .26]), .41 (95% CI [.21, .51]) and .51 (95% CI = .42, .61), respectively. In addition, the additive genetic correlation between NE and HIP was 1.0 (95% CI [.52, 1.00]), indicating that additive genetic factors are entirely shared between the two phenotypes. Nonadditive genetic influences were unique to HIP and not responsible for the NE-HIP association. Nonshared environmental correlation was significant but modest (re = .18, 95% CI [.06, .30]).

Effortful control moderates the relation between negative emotionality and socially appropriate behavior.

The current study investigated the relation between negative emotionality and socially appropriate behavior in a diverse sample of preschool and kindergarten children (N = 74). More specifically, we tested whether effortful control would moderate this relation. A computerized task measured children's effortful control by assessing their accuracy in shifting attention between different emotionally valenced faces (happy and angry) while inhibiting their responses to neutral faces. Teachers completed the Affect Intensity Scale-Child Version to assess child negative emotionality as well as the Preschool and Kindergarten Behavior Scales to assess two aspects of socially appropriate behavior (social cooperation and inhibition of externalizing behavior). Regression analyses indicated that children with high negative emotionality and strong effortful control had fewer externalizing problems and greater social cooperation compared with their counterparts with weaker effortful control. These findings support and extend previous research suggesting that effortful control may protect children, particularly those with high negative emotionality, from poor social outcomes. A novel contribution of this study is its use of an attention shifting task that incorporates emotionally salient stimuli. These findings have important implications for educators working with young children who encounter increased expectations for regulating their behavior during preschool and kindergarten.

Examining the role of socioeconomic status and temperament in the hair cortisol levels of infants.

Socioeconomic status (SES) appears to be an important contextual factor in children's developmental outcomes, including their responses to stress. However, some children are more susceptible to its effects than others. Hair cortisol is a newer method of assessing the activity of the HPA axis, providing cumulative cortisol levels. The present article examined whether temperament (negative emotionality) moderates the association between an SES index and the hair cortisol concentration (HCC) of infants. Sixty infants from 6 to 15 months of age were recruited, of which 49 had sufficient hair for cortisol analysis. The SES index was calculated from the education levels of the mothers, family income, and a scale measuring the quality of the home environment. Negative emotionality was measured with the three sub-scales of the Infant Behavior Questionnaire (falling reactivity, distress to limitations, and fear). Among infants low in negative emotionality, there was no association between SES and cortisol. In contrast, among those high in negative emotionality, a significant association was obtained. These infants showed lower levels of HCC in lower-SES environments. The findings suggest that there are individual differences in reacting to the environment, and low levels of cortisol (not high) were found in susceptible infants in lower-SES families.

The role of maternal touch in the association between SLC6A4 methylation and stress response in very preterm infants.

Very preterm (VPT) infants requiring hospitalization in the Neonatal Intensive Care Unit (NICU) are exposed to several stressful procedural experiences. One consequence of NICU-related stress is a birth-to-discharge increased serotonin transporter gene (SLC6A4) methylation that has been associated with poorer stress regulation at 3 months of age. Maternal touch is thought to support infants' stress response, but its role in moderating the effects of SLC6A4 methylation changes is unknown. The aim of this study was to assess the role of maternal touch in moderating the association between increased SLC6A4 methylation and stress response in 3-month-old VPT infants. Twenty-nine dyads were enrolled and at 3 months (age corrected for prematurity), participated in the Face-to-Face Still-Face paradigm to measure infants' stress response (i.e., negative emotionality) and the amount of maternal touch (i.e., dynamic and static). Results showed that low level of maternal touch is associated with high level of negative emotionality during social stress. Furthermore, during NICU stay SLC6A4 methylation in VPT exposed to low level of maternal touch at 3 months was associated with increased negative emotionality. Thus, low levels of maternal static touch can intensify the negative effects of SLC6A4 epigenetic changes on stress response in 3-month-old VPT infants.