Impulsivity and genetic variants in DRD2 and ANKK1 moderate longitudinal associations between sleep problems and overweight from ages 5 to 11.

OBJECTIVE: Short sleep duration and sleep problems increase risks of overweight and weight gain. Few previous studies have examined sleep and weight repeatedly over development. This study examined the associations between yearly reports of sleep problems and weight status from ages 5 to 11. Although, previous studies have shown that inter-individual differences moderate the effect of short sleep duration on weight, it is not known whether inter-individual differences also moderate the effect of sleep problems on weight. We tested how the longitudinal associations between sleep problems and weight status were moderated by impulsivity and genetic variants in DRD2 and ANKK1. DESIGN: Seven-year longitudinal study. PARTICIPANTS: A total of 567 children from the Child Development Project for the analysis with impulsivity and 363 for the analysis with genetic variants. MEASUREMENTS AND RESULTS: Sleep problems and weight status were measured by mothers' reports yearly. Impulsivity was measured by teachers' reports yearly. Six single-nucleotide polymorphisms located in DRD2 and ANKK1 were genotyped. Data were analyzed using multilevel modeling. Higher average levels of sleep deprivation across years were associated with greater increases in overweight (P=0.0024). Sleep problems and overweight were associated at both within-person across time (P<0.0001) and between-person levels (P<0.0001). Impulsivity and two polymorphisms, rs1799978 and rs4245149 in DRD2, moderated the association between sleep problems and overweight; the association was stronger in children who were more impulsive (P=0.0022), in G allele carriers for rs1799978 (P=0.0007) and in A allele carriers for rs4245149 (P=0.0002). CONCLUSIONS: This study provided incremental evidence for the influence of sleep problems on weight. Findings of DRD2, ANKK1 and impulsivity are novel; they suggest that reward sensitivity and self-regulatory abilities might modulate the influences of sleep on weight gain. The analysis of polymorphisms was restricted to European Americans and hence the results might not generalize to other populations.

Mechanisms in the cycle of violence.

Two questions concerning the effect of physical abuse in early childhood on the child's development of aggressive behavior are the focus of this article. The first is whether abuse per se has deleterious effects. In earlier studies, in which samples were nonrepresentative and family ecological factors (such as poverty, marital violence, and family instability) and child biological variables (such as early health problems and temperament) were ignored, findings have been ambiguous. Results from a prospective study of a representative sample of 309 children indicated that physical abuse is indeed a risk factor for later aggressive behavior even when the other ecological and biological factors are known. The second question concerns the processes by which antisocial development occurs in abused children. Abused children tended to acquire deviant patterns of processing social information, and these may mediate the development of aggressive behavior.

Social information-processing patterns partially mediate the effect of early physical abuse on later conduct problems.

The authors tested the hypothesis that early physical abuse is associated with later externalizing behavior outcomes and that this relation is mediated by the intervening development of biased social information-processing patterns. They assessed 584 randomly selected boys and girls from European American and African American backgrounds for the lifetime experience of physical abuse through clinical interviews with mothers prior to the child's matriculation in kindergarten. Early abuse increased the risk of teacher-rated externalizing outcomes in Grades 3 and 4 by fourfold, and this effect could not be accounted for by confounded ecological or child factors. Abuse was associated with later processing patterns (encoding errors, hostile attributional biases, accessing of aggressive responses, and positive evaluations of aggression), which, in turn, predicted later externalizing outcomes.

Reactive and proactive aggression in school children and psychiatrically impaired chronically assaultive youth.

The authors proposed that reactively aggressive and proactively aggressive types of antisocial youth would differ in developmental histories, concurrent adjustment, and social information-processing patterns. In Study 1, 585 boys and girls classified into groups called reactive aggressive, proactive aggressive, pervasively aggressive (combined type), and nonaggressive revealed distinct profiles. Only the reactive aggressive groups demonstrated histories of physical abuse and early onset of problems, adjustment problems in peer relations, and inadequate encoding and problem-solving processing patterns. Only the proactive aggressive groups demonstrated a processing pattern of anticipating positive outcomes for aggressing. In Study 2, 50 psychiatrically impaired chronically violent boys classified as reactively violent or proactively violent demonstrated differences in age of onset of problem behavior, adjustment problems, and processing problems.

The developmental course of violence and aggression. Mechanisms of family and peer influence.

This article presents an overview of current research and thinking on the developmental course of aggression and violent behavior from early childhood through adolescence. Differing developmental trajectories are highlighted, and salient family and peer influences are described. Acquired social information processing patterns are discussed as potential mediators of the link between social experience in the family and peer group and individual differences in children's aggressive behavior. The need for developmentally sensitive models that focus on the interplay of family and peer experience, information processing patterns, and onset and chronicity of aggression is stressed.

Quality of early family relationships and individual differences in the timing of pubertal maturation in girls: a longitudinal test of an evolutionary model.

In an 8-year prospective study of 173 girls and their families, the authors tested predictions from J. Belsky, L. Steinberg, and P. Draper's (1991) evolutionary model of individual differences in pubertal timing. This model suggests that more negative-coercive (or less positive-harmonious) family relationships in early childhood provoke earlier reproductive development in adolescence. Consistent with the model, fathers' presence in the home, more time spent by fathers in child care, greater supportiveness in the parental dyad, more father-daughter affection, and more mother-daughter affection, as assessed prior to kindergarten, each predicted later pubertal timing by daughters in 7th grade. The positive dimension of family relationships, rather than the negative dimension, accounted for these relations. In total, the quality of fathers' investment in the family emerged as the most important feature of the proximal family environment relative to daughters' pubertal timing.

Interaction of temperamental resistance to control and restrictive parenting in the development of externalizing behavior.

Child temperament and parental control were studied as interacting predictors of behavior outcomes in 2 longitudinal samples. In Sample 1, data were ratings of resistant temperament and observed restrictive control in infancy-toddlerhood and ratings of externalizing behavior at ages 7 to 10 years; in Sample 2, data were retrospective ratings of temperament in infancy-toddlerhood, observed restrictive control at age 5 years, and ratings of externalizing behavior at ages 7 to 11 years. Resistance more strongly related to externalizing in low-restriction groups than in high-restriction groups. This was true in both samples and for both teacher- and mother-rated outcomes. Several Temperament x Environment interaction effects have been reported previously, but this is one of very few replicated effects.

Adult individual differences as moderators of child effects.

Experimentally varying child behavior stimuli and then assessing the extent to which adult individual differences (especially in cognitions) moderate the effect of the child on the adult is a variation on the usual methods in child effects research. This method allows description of the role of child effects in more complex adult-child systems. Existing literature incorporating this approach is reviewed, with emphasis on the moderating effects of sex, personality, and perceptions. A previously unreported study is described as an example of a multivariate approach to exploring the relationships between adult individual differences and the effects of infant stimuli. The study suggests that experienced caregivers who do not have much liking for infants see themselves as likely to provide appropriate, but minimally social care for an infant. Conversely, the study suggests that inexperienced adults who like infants very much see themselves as providing more extensive and social caregiving, although it would not always be appropriate to the infant's state.

A cross-domain growth analysis: externalizing and internalizing behaviors during 8 years of childhood.

In a sample of 405 children assessed in kindergarten through the seventh grade, we determined the basic developmental trajectories of mother-reported and teacher-reported externalizing and internalizing behaviors using cross-domain latent growth modeling techniques. We also investigated the effects of race, socioeconomic level, gender, and sociometric peer-rejection status in kindergarten on these trajectories. The results indicated that, on average, the development of these behaviors was different depending upon the source of the data. We found evidence of the codevelopment of externalizing and internalizing behaviors within and across reporters. In addition, we found that African-American children had lower levels of externalizing behavior in kindergarten as reported by mothers than did European-American children but they had greater increases in these behaviors when reported by teachers. Children from homes with lower SES levels had higher initial levels of externalizing behaviors and teacher-reported internalizing behaviors. Males showed greater increases in teacher-reported externalizing behavior over time than did the females. Rejected children had trajectories of mother-reported externalizing and internalizing behavior that began at higher levels and either remained stable or increased more rapidly than did the trajectories for non-rejected children which decreased over time.

Early behavior problems as a predictor of later peer group victimization: moderators and mediators in the pathways of social risk.

This study is a prospective investigation of the predictive association between early behavior problems (internalizing, externalizing, hyperactivity-impulsiveness, immaturity-dependency) and later victimization in the peer group. Teacher ratings of the behavioral adjustment of 389 kindergarten and 1st-grade children (approximate age range of 5 to 6 years-old) were obtained, using standardized behavior problem checklists. These ratings predicted peer nomination scores for victimization, obtained 3 years later, even after the prediction associated with concurrent behavior problems was statistically controlled. Further analyses suggested that the relation between early behavior problems and later victimization is mediated by peer rejection and moderated by children's dyadic friendships. Behavior problems appear to play an important role in determining victimization within the peer group, although the relevant pathways are complex and influenced by other aspects of children's social adjustment.

Discipline responses: influences of parents' socioeconomic status, ethnicity, beliefs about parenting, stress, and cognitive-emotional processes.

Direct and indirect precursors to parents' harsh discipline responses to hypothetical vignettes about child misbehavior were studied with data from 978 parents (59% mothers; 82% European American and 16% African American) of 585 kindergarten-aged children. SEM analyses showed that parents' beliefs about spanking and child aggression and family stress mediated a negative relation between socioeconomic status and discipline. In turn, perception of the child and cognitive-emotional processes (hostile attributions, emotional upset, worry about child's future, available alternative disciplinary strategies, and available preventive strategies) mediated the effect of stress on discipline. Similar relations between ethnicity and discipline were found (African Americans reported harsher discipline), especially among low-income parents. Societally based experiences may lead some parents to rely on accessible and coherent goals in their discipline, whereas others are more reactive.

Mothers' social coaching, mother-child relationship style, and children's peer competence: is the medium the message?

Contributions of mothers' social coaching and responsive style to preschoolers' peer competence were evaluated in 2 studies. In Study 1, 43 mother-child dyads participated in 3 laboratory tasks; videotapes were coded for responsive interaction style in play, advice regarding videotaped peer dilemmas (coaching), and nonsocial teaching in a puzzle task. Coaching and style were largely independent and were correlated with measures of social competence. In Study 2 (n = 62), coaching and style uniquely predicted teacher ratings, but only style predicted peer acceptance. To investigate whether coaching mediated the effects of style and/or whether style moderated the effects of coaching, the samples were combined. No evidence was found for mediation, but coaching was a more powerful predictor of lower levels of boys' aggression when the mother-child relationship was less responsive. Discussion focuses on models of socialization that stress the interplay of general style and specific socialization practices in promoting social competence.

Continuity of individual differences in the mother-infant relationship from six to thirteen months.

The current study searched for continuities in mother-infant interaction observed at home, maternally perceived infant difficultness, and infant developmental competency. Also assessed were the possible moderator variables of maternal report of satisfaction with adjustment to the infant and background characteristics, for example, SES, presence of other young children, and infant gender. 128 dyads were assessed at ages 6 and 13 months. Many of the variables used to evaluate continuity were composites based on factor analysis. Bivariate correlations between 6- and 13-month variables produced a complex picture. In broad overview, as predicted by the prior literature, they indicated some degree of stability for mother variables and markedly less for the infant variables. Canonical correlation analysis yielded 3 significant canonical variates, producing a more integrated picture. The dimensions of continuity revealed by these variates were (1) Affectionate, Intellectually Stimulating Mothering, which had modest-to-moderate links to the indexes of infant competence; (2) Infant Temperamental Difficultness, which was determined mainly by consistency in mother report on 2 age-adjusted versions of the Infant Characteristics Questionnaire but which also contained loadings for objectively observed infant fussing, crying, and social demandingness; and (3) an unnamed dimension which resembles a pattern of intense involvement, both positive and negative, seen in older, clinically referred families.

Socialization mediators of the relation between socioeconomic status and child conduct problems.

The goal was to examine processes in socialization that might account for an observed relation between early socioeconomic status and later child behavior problems. A representative sample of 585 children (n = 51 from the lowest socioeconomic class) was followed from preschool to grade 3. Socioeconomic status assessed in preschool significantly predicted teacher-rated externalizing problems and peer-rated aggressive behavior in kindergarten and grades 1, 2, and 3. Socioeconomic status was significantly negatively correlated with 8 factors in the child's socialization and social context, including harsh discipline, lack of maternal warmth, exposure to aggressive adult models, maternal aggressive values, family life stressors, mother's lack of social support, peer group instability, and lack of cognitive stimulation. These factors, in turn, significantly predicted teacher-rated externalizing problems and peer-nominated aggression and accounted for over half of the total effect of socioeconomic status on these outcomes. These findings suggest that part of the effect of socioeconomic status on children's aggressive development may be mediated by status-related socializing experiences.

Some consequences of early harsh discipline: child aggression and a maladaptive social information processing style.

Although a number of studies have reported a relation between abusive parental behavior and later aggressive behavior in the victim, many of these investigations have had methodological limitations that make precise interpretation of their results problematic. In the present study, we attempted to determine whether harsh parental discipline occurring early in life was associated with later aggression and internalizing behavior in children, using a prospective design with randomly selected samples to avoid some of these methodological difficulties. Structural equation modeling indicated a consistent relation between harsh discipline and aggression in 2 separate cohorts of children. This relation did not appear to be due to possible confounding factors such as child temperament, SES, and marital violence, although there was some indication in our data that the latter variables were related to child aggression. In addition, our analyses suggested that the effect of harsh discipline on child aggression may be mediated at least in part by maladaptive social information processing patterns that develop in response to the harsh discipline.

The early socialization of aggressive victims of bullying.

This study reports the first prospective investigation of the early family experiences of boys who later emerged as both aggressive and bullied (i.e., aggressive victims) during their middle childhood years. It was hypothesized that a history of violent victimization by adults leads to emotion dysregulation that results in a dual pattern of aggressive behavior and victimization by peers. Interviews with mothers of 198 5-year-old boys assessed preschool home environments. Four to 5 years later, aggressive behavior and peer victimization were assessed in the school classroom. The early experiences of 16 aggressive victims were contrasted with those of 21 passive (nonaggressive) victims, 33 nonvictimized aggressors, and 128 normative boys. Analyses indicated that the aggressive victim group had experienced more punitive, hostile, and abusive family treatment than the other groups. In contrast, the nonvictimized aggressive group had a history of greater exposure to adult aggression and conflict, but not victimization by adults, than did the normative group, whereas the passive victim group did not differ from the normative group on any home environment variable.

The impact of after-school peer contact on early adolescent externalizing problems is moderated by parental monitoring, perceived neighborhood safety, and prior adjustment.

Unsupervised peer contact in the after-school hours was examined as a risk factor in the development of externalizing problems in a longitudinal sample of early adolescents. Parental monitoring, neighborhood safety, and adolescents' preexisting behavioral problems were considered as possible moderators of the risk relation. Interviews with mothers provided information on monitoring, neighborhood safety, and demographics. Early adolescent (ages 12-13 years) after-school time use was assessed via a telephone interview in grade 6 (N = 438); amount of time spent with peers when no adult was present was tabulated. Teacher ratings of externalizing behavior problems were collected in grades 6 and 7. Unsupervised peer contact, lack of neighborhood safety, and low monitoring incrementally predicted grade 7 externalizing problems, after controlling for family background factors and grade 6 problems. The greatest risk was for those unsupervised adolescents living in low-monitoring homes and comparatively unsafe neighborhoods. The significant relation between unsupervised peer contact and problem behavior in grade 7 held only for those adolescents who already were high in problem behavior in grade 6. These findings point to the need to consider individual, family, and neighborhood factors in evaluating risks associated with young adolescents' after-school care experiences.

Dimensions of individuality in the mother-infant relationship at six months of age.

Prior studies on mothers and infants have explored a great many individual variations. To date, however, the empirically based meaningfulness of these variations is quite limited. The current study attempts to achieve a relatively comprehensive empirical description of the mother-infant relationship at the age of 6 months, with special focus on possible correlates of infant developmental competence. 168 mother-infant pairs contributed data on a wide variety of measures, including the following categories: (a) observed interactions, at home and in the laboratory; (b) mother perception of the infant's temperament, mother personality, social support, and family adjustment to the new baby; (c) infant performance on the Bayley test; and (d) background variables such as birth order and economic status. Relationships among the various measures were modeled with factor analytic methods and interpreted in connection with current research issues. The most important findings are the following: (1) The main factor is widely generalizable dimension in maternal behavior of warm, responsive interaction with the infant. (2) Some elements of this main factor overlap with another factor indexing the extent to which mother impresses observer as educationally stimulating. Social class was associated with this teaching factor, but not with the first, more affection- and play-oriented, dimension. (3) Mother perceptions of difficult temperament in the infant were associated with objectively observed crying and fussing but were essentially independent of the major dimensions of maternal behavior. (4) Observed active and happy behaviors of the infant were somewhat related to normative status on the Bayley test, but neither active and happy behavior nor Bayley score correlated with the important dimensions of maternal behavior.

Multiple risk factors in the development of externalizing behavior problems: group and individual differences.

The aim of this study was to test whether individual risk factors as well as the number of risk factors (cumulative risk) predicted children's externalizing behaviors over middle childhood. A sample of 466 European American and 100 African American boys and girls from a broad range of socioeconomic levels was followed from age 5 to 10 years. Twenty risk variables from four domains (child, sociocultural, parenting, and peer-related) were measured using in-home interviews at the beginning of the study, and annual assessments of externalizing behaviors were conducted. Consistent with past research, individual differences in externalizing behavior problems were stable over time and were related to individual risk factors as well as the number of risk factors present. Particular risks accounted for 36% to 45% of the variance, and the number of risks present (cumulative risk status) accounted for 19% to 32% of the variance, in externalizing outcomes. Cumulative risk was related to subsequent externalizing even after initial levels of externalizing had been statistically controlled. All four domains of risk variables made significant unique contributions to this statistical prediction, and there were multiple clusters of risks that led to similar outcomes. There was also evidence that this prediction was moderated by ethnic group status, most of the prediction of externalizing being found for European American children. However, this moderation effect varied depending on the predictor and outcome variables included in the model.

Peer status and aggression in boys' groups: developmental and contextual analyses.

The social transactions of popular, rejected, neglected, and average first- and third-grade boys were examined during their initial encounters with peers. 23 groups of 5 or 6 boys each were observed for 45-min free-play sessions conducted on 5 consecutive days, with sociometric interviews following each session. Social preference in the play groups correlated significantly with classroom social preference after the third and subsequent play sessions for the third graders, and after the fourth and subsequent sessions for the first graders. The observational coding system distinguished 4 types of aggressive behavior that were hypothesized to relate to peer status in different ways. The first, rough play, was not related to peer status. However, rejected boys at both ages displayed significantly higher rates of angry reactive aggression and instrumental aggression than average boys. The relation between bullying and peer status varied with the age of the child. Popular first graders engaged in more bullying than average first graders, but popular third graders did not differ from average in bullying. Other questions concerned the temporal relation between play group behaviors and social preference scores within the group. Socially interactive behaviors anteceded high preference by peers, and low preference in turn led to social isolation in subsequent sessions.