Modeling trajectories of physical aggression from infancy to pre-school age, their early predictors, and school-age outcomes.

This study identified latent trajectories of physical aggression (TPA) from infancy to preschool age and evaluated (a) effects of early parent, parenting and child predictors on TPA as well as on social, behavioral, and academic functioning in Grade 2, and (b) TPA effects net of early predictor effects on Grade 2 functioning. We used data from the Behavior Outlook Norwegian Developmental Study (BONDS), which included 1,159 children (559 girls). Parents reported on risk and protective factors, and on physical aggression from 1 to 5 years of age; teachers reported on Grade 2 outcomes. We employed latent class growth curve analyses and identified nine TPA. In fully adjusted models simultaneously testing all associations among predictors, trajectories, and outcomes, maternal and paternal harsh parenting, child gender, and sibling presence predicted TPA, which significantly predicted externalizing and academic competence in Grade 2. Child gender had a pervasive influence on all outcomes as well as on TPA. To our knowledge, this is the first trajectory study to determine which predictors are most proximal, more distal, or just confounded, with their relative direct effect sizes, and to link early paternal as well as maternal harsh parenting practices with children's TPA. Our findings underscore the need to include fathers in developmental research and early prevention and intervention efforts.

Duration of Breastfeeding and Supportive Paternal Caregiving in Early Childhood and the Potential Mediating Function of Maternal Caregiving.

OBJECTIVE: Supportive paternal caregiving is influenced by contextual factors, including maternal caregiving behaviors. Although longer periods of breastfeeding have been found to be associated with higher levels of maternal supportive parenting, it remains unknown whether the benefits of breastfeeding also extend to fathers' supportive caregiving. This study tested the indirect relation between the duration of breastfeeding and paternal supportive parenting through maternal supportive parenting. METHODS: Participating families (N = 623) were from the Behavior Outlook Norwegian Developmental Study, a population-based longitudinal study in Southeast Norway. Path analysis was used to test associations between the duration of breastfeeding in the first year (parent report) and paternal supportive parenting (observed, 36 months), as potentially mediated by maternal supportive parenting (observed, 24 months). RESULTS: After controlling for sociodemographic and birth factors, a longer duration of breastfeeding was indirectly associated with higher levels of observed paternal supportive parenting through maternal supportive parenting. CONCLUSION: The current findings suggest that the longer breastfeeding duration during the first year of life (i.e., infancy) might have important implications for both maternal and paternal supportive parenting in toddlerhood.

Pandemic-Related Stress Symptoms Among Norwegian Parents of Adolescents in Grades 6 to 8.

We investigated pandemic-related stress symptoms during the first COVID-19 lockdown period in spring 2020 among parents of adolescents that were 11 to 13 years old in the study period. We also investigated whether parental stress symptoms were associated with family situation and family activities during lockdown. Altogether 147 couples reported about their own trauma-related stress symptoms following the outbreak of the pandemic. Among the respondents, 9.5% of the mothers and 10.2% of the fathers had scores over cutoff on the screener (IES-6) measuring stress symptoms, a non-significant gender difference. Scores on the screener were not associated with family contamination or lockdown consequences. Family activities during lockdown did not impact the pandemic stress symptom levels. Whereas, the experience of the COVID-19 pandemic pose a stressor to most people, it is unlikely to be a criterion A event for other than directly affected families.

Duration of Breastfeeding Mediates the Association Between Early Socioeconomic Risk and Child Vocabulary at Age 4.

OBJECTIVE: Early-life socioeconomic disadvantage is associated with both obesity and lower cognitive abilities in childhood. One theorized underlying mechanism is breastfeeding duration because breast milk contains nutrients that can promote healthy adiposity profiles and stimulate brain development. However, studies have rarely examined these potential associations with child body mass index (BMI) in high-income Western countries, much less investigated breastfeeding duration as a mediator of the relationship between childhood socioeconomic status (SES) and later child vocabulary. The current study aimed to prospectively examine associations between early-life family socioeconomic risk and both child BMI and vocabulary at age 4 in a Norwegian cohort and the potential mediating contribution of breastfeeding duration. METHODS: The Behavior Outlook Norwegian Developmental Study (BONDS) followed 1159 families and their children from 6 months of age onward. Parents reported on SES and breastfeeding duration in infancy, and child BMI and vocabulary ability were assessed at age 4. Direct and indirect effects were estimated using a path model that adjusted for several demographic and perinatal covariates (e.g., parental nativity and birthweight). RESULTS: Family socioeconomic risk was significantly and negatively related to child vocabulary but was unrelated to child BMI. In addition, breastfeeding duration mediated the association between family socioeconomic risk and child vocabulary, with greater family socioeconomic risk associated with a shorter breastfeeding duration, which, in turn, predicted poorer child vocabulary. CONCLUSION: The current findings suggest that longer breastfeeding duration is a viable target for preventatively promoting child vocabulary, especially among families at socioeconomic risk.

Analysing four Norweigian population-based samples using the six-month version of the Ages and Stages Questionnaire showed few relevant clinical differences.

AIM: We investigated whether there were clinically relevant differences in the area mean scores of the six-month Ages and Stages Questionnaire (ASQ) between four Norwegian population-based samples. METHODS: Area mean scores and standard deviations (SDs) were investigated for the five developmental areas of the ASQ: communication, gross motor, fine motor, problem solving and personal-social. Sample sizes varied from 166 to 1192 and the ASQ was completed on paper or by computer. ASQ scores in the four samples were compared using ANOVA and Tukey's procedure was used to adjust for multiple comparisons. RESULTS: The ASQ mean area scores were generally similar in the four data sets, with few clinically relevant differences, defined as a mean difference of greater than five points, which is the smallest increment in area score, or an effect size of >0.5 in absolute value. All the clinically relevant differences occurred when samples used a modified ASQ administration format. Several additional minor differences were statistically significant, which was expected due to the large samples. CONCLUSION: These results support the original Norwegian normative findings for the ASQ six-month form and the ASQ's use as a low-cost developmental screening tool in Norway, at least when the original format is administered.

Measuring Effortful Control Using the Children's Behavior Questionnaire-Very Short Form: Modeling Matters.

Effortful control (EC) is an important concept in the research on self-regulation in children. We tested 2 alternative factor models of EC as measured by the Children's Behavior Questionnaire-Very Short Form (CBQ-VSF; Putnam & Rothbart, 2006 ) in a large sample of preschoolers (N = 1,007): 1 lower order and 1 hierarchical second-order structure. Additionally, convergent and predictive validity of EC as measured by the CBQ-VSF were investigated. The results supported a hierarchical model. Moderate convergent validity of the second-order latent EC factor was found in that it correlated with compliance and observed EC tasks. Both CBQ-VSF EC measures were also negatively correlated with child physical aggression. The results have implications for the measurement, modeling, and interpretation of EC applying the CBQ.

Normative development of physical aggression from 8 to 26 months.

This study investigated the normative use and developmental course of physical aggression (PA), defined as use of physical force such as hitting, biting, and kicking, from 8 to 26 months and predictors thereof. We used data from the Behavior Outlook Norwegian Developmental Study, comprising 1,159 children (559 girls and 600 boys). Both mothers and fathers reported frequently about their child's use of PA in personal and telephone interviews. Mean number of reports per child was 7.16 (SD 1.70), with 90% having at least 6 reports. We employed Rasch scaling to construct a single linear PA measure and multilevel growth curve modeling to address the research questions. The results confirm that the development of PA is nonlinear, with a peak in frequency at about 20-22 months, which is followed by a decline toward 26 months. There is both within- and between-child variance in the development of PA. Higher levels of PA were predicted by the presence of a same-age sibling, maternal and paternal mental distress, and difficult child temperament (high activity level and distress due to limitations), whereas the main effect of gender was only trend-significant. Growth of PA across this developmental period was predicted by the presence of a same-age sibling and high activity level. The results both support and transcend previous research within this field.

Family concordance and gender differences in parent-child structured interaction at 12 months.

This observational study examined family concordance and gender differences in early parent-child interaction in the family supportive sociopolitical context of Norway. Mothers and fathers from 39 Norwegian families were observed on separate occasions with their 12-month-old children (20 girls and 19 boys). Data were recorded from observations using microsocial coding methodology based on social interaction learning theory. We found no within-family concordance between mothers' and fathers' behaviors with their child. The children's negative engagement with each parent was moderately correlated. For parents with boys, fathers were overall more positively engaged than mothers. Moreover, fathers of boys displayed more positive engagement than those of girls, whereas mothers of girls and boys displayed similar levels of positive engagement. In contrast to previous findings, mothers did not verbalize more than fathers. Girls were overall more positively engaged during interaction with both mothers and fathers than boys. Thus, in a sociopolitical context that facilitates early parent-child relationships and gender equality, there were few but noteworthy gender differences in parent-child interaction at 12 months.

Trajectories of maternal symptoms of depression and anxiety over 13 years: the influence of stress, social support, and maternal temperament.

BACKGROUND: Depression and anxiety are the most common mental health problems among women, with various negative impacts both for the women concerned and their families. Greater understanding of developmental trajectories of maternal symptoms of depression and anxiety over the child rearing period would have significant benefits for public health, informing prevention and treatment approaches. The aim of the current study was to examine whether stressors related to child rearing and living conditions, social support, and maternal temperament, predicted mothers' membership in groups with different trajectories of symptoms of depression and anxiety during 13 years of the child rearing phase. METHODS: The data were from a prospective, longitudinal study of 913 mothers in Norway followed from when their children were 18 months old (time 1) until they were 14.5 years (time 6) (the TOPP study). Multinomial logistic regression analyses were used to test whether child related stressors, stressors related to the living conditions, social support and maternal temperament at time 1 predicted membership in groups based on maternal symptoms of depression and anxiety over the subsequent 13 years. RESULTS: Temperamental distress, followed by child related stressors, were the strongest predictors of membership in a group with high symptoms of depression and anxiety over time. Stressors related to living conditions, and social support from partner and friends/family were also significant predictors. No interaction effects among predictors were found. CONCLUSIONS: This study indicates that factors present early in the child rearing phase may provide substantial prediction of the variance in maternal symptoms of depression and anxiety over the following 13 years. Temperamental distress and child related stressors were the strongest predictors of membership in different depression and anxiety symptom trajectory groups.

Trajectories of maternal symptoms of anxiety and depression. A 13-year longitudinal study of a population-based sample.

BACKGROUND: There is a lack of population-based studies of developmental trajectories following mothers throughout the whole child-rearing phase and there are few longitudinal studies focusing on both symptoms of depression and anxiety. The aim of the current study is to identify latent trajectory groups based on counts of symptoms of anxiety and depression among mothers throughout the child-rearing phase and the relations of the latent groups to maternal socio-demographic variables. METHODS: Data is from a prospective, longitudinal study of nearly 1000 families in Norway followed from when the index children were 18 months until they were 14.5 years old (the TOPP study). The study used latent profile analysis (LPA) to identify latent groups of mothers with distinct trajectories across time of symptom counts. Latent group differences on socio-demographic variables were tested with one-way ANOVAs, chi-square tests and exact tests. RESULTS: Six trajectories based on maternal scores from six waves of data collection of symptoms of anxiety and depression were identified; a 'No symptoms' group with mothers without symptoms; a 'Low' group with mothers reporting low symptom levels; a 'Moderate-low' group with mothers reporting moderately low symptom levels; a 'Moderate' group with mothers with moderate symptoms; a 'High-chronic' group with mothers with overall high symptom levels; and a 'Low-rising' group with mothers starting with a low symptom level that increased over time. The mothers in the High-chronic symptom group differed from the other mothers on several socio-demographic variables. They were significantly younger than the mothers in the Low group comprising the oldest mothers. The mothers in the High-chronic group had significantly lower education, were less likely to have paid work and were less likely to be living with a partner than the mothers in the other groups. CONCLUSIONS: The study shows socio-demographic differences between mothers classified into six trajectory groups based on symptoms of anxiety and depression covering 13 years of the child-rearing period. Specific socio-demographic risk factors characterised mothers in the High-chronic symptom group. Identifying subgroups with enduring problems might inform more targeted preventive efforts.

Temperament profiles from infancy to middle childhood: development and associations with behavior problems.

The authors applied I-States as Objects Analysis (ISOA), a recently proposed person-oriented analytic approach, to the study of temperament development in 921 Norwegian children from a population-based sample. A 5-profile classification based on cluster analysis of standardized mother reports of activity, sociability, emotionality, and shyness at ages 18 months, 30 months, 4-5 years, and 8-9 years was interpretable and highly replicable. The prevalence of temperament profiles changed markedly with age, and individual stability in temperament profiles was significant. Specific typical and atypical developmental sequences of profiles were identified. Selective patterns of concurrent group differences in externalizing and internalizing problems by temperament profiles were remarkably similar across ages. The findings to some degree support the notion that individual temperament-variable values take on meaning in relation to the whole individual configuration and indicate some lawfulness in temperament changes over time. Future person-oriented studies of temperament development should replicate the current results using multiple data sources, rigorous tests of gender differences, and latent group modeling.

A validation study of the Norwegian version of the Ages and Stages Questionnaires.

AIM: To explore the construct validity of the ASQ in relation to premature birth; maternal age, completeness of the family and level of education; and the child's gender. METHODS: Norwegian mothers' evaluations of 1172 children who completed age appropriate ASQs twice were statistically analysed by means of univariate and multivariate methods. RESULTS: The developmental level of girls is on average higher than that of boys at both assessments and there is a substantial increase between follow-up assessments in all ASQ scores except for gross motor skills. The mother's level of education; whether the child was born prematurely or at full-term; and the interaction between the child's gender and his/her mother's level of education are important factors relating to the child's developmental status in both assessments. CONCLUSION: The results that were derived by means of the Ages and Stages Questionnaires concerning the impact of maternal socio-demographical factors, the child's gender, and premature birth upon early childhood development largely confirm the findings in the literature supporting the construct validity of the ASQ. The ASQ was found to be an effective diagnostic tool of developmental delay and/or disturbances. The development of gender dependent norms is recommended.

Factor structure and individual patterns of DSM-IV conduct disorder criteria in adolescent psychiatric inpatients.

We investigated the factor structure of the DSM-IV conduct disorder (CD) diagnostic criteria and typical individual patterns of CD subscales in an adolescent inpatient population using detailed hospital records of a Norwegian nationwide sample of 1087 adolescent psychiatric inpatients scored for the 15 DSM-IV CD criteria. Varimax rotated principal components and full-information factor analyses of 12 CD criteria were carried out separately for boys and girls employing two methods. Standardized values on three subscales of CD criteria were subjected to Ward's method of hierarchical cluster analyses followed by k-means relocation employing a double cross-replication design. Similar factor structures emerged regardless of factoring method and gender. With the exception of Criteria 8 ("Fire setting") and 14 ("Run away from home") the factor loadings for both genders were in accordance with Loeber's tripartite model, with Aggression, Delinquency, and Rule Breaking factors largely corresponding to Loeber's overt, covert and authority conflict pathways. A five-cluster solution proved highly replicable and interpretable. One cluster gathered adolescents without CD, and the remaining four described groups with different conceptually meaningful constellations of CD criteria, which were not equally prevalent in each gender. Delinquency appeared in all symptomatic clusters. The cluster analytic results highlighted typical forms of expressions of conduct problems, and the fact that these forms may not be equally prevalent in girls and boys even while the underlying structure of conduct problems may be similar across genders. Future research should address the prediction of specific outcomes from CD criteria subscales or constellations.

Prediction of adolescent and adult delinquency from childhood Rorschach ratings.

Relatively few studies have predicted adolescent or adult delinquency from childhood Rorschach data. Incremental validity of Rorschach measures over other known consistent and more easily obtained predictors has typically not been investigated. We addressed Rorschach data's incremental validity over mother's reports of externalizing behavior and mother-child relations for predicting officially registered adolescent and adult delinquency in a longitudinal study of 122 Swedish men. The Rorschach measures we used were aggregates of blind, prospectively performed, global expert ratings based on a holistic evaluation of protocols. An aggregate of Rorschach-based ratings of ego strength significantly improved the prediction of delinquency in adolescence and adulthood over and above earlier identified best predictors (mother's ratings of mother-child relations and externalizing problem behavior).

Why do identical twins differ in personality: shared environment reconsidered.

While heritability studies show that most of the variance in adult personality can be attributed to genetic or so-called nonshared environmental influence, this does not mean that shared events lack importance for the development of later personality differences. We studied the relationship between Big Five personality differences in monozygotic (MZ) twins at age 29, and life stressors at age 6 to 15, using prospective data from 26 MZ pairs studied from birth onwards. A positive significant correlation was found between stressors in childhood and early adolescence, and intrapair personality differences in Agreeableness, Openness, Conscientiousness, and five-factor profiles. We note that the effects of shared events are labeled "nonshared" environment when the effect is to make siblings more different. Case examples illustrate the relationship between stress and personality differences, and provide hypotheses for further studies in larger samples.