Siblings of children with chronic disorders are at a heightened risk for internalizing and externalizing problems. Studies on sibling mental health typically use parent report, and sometimes sibling self-report, but do not include the perspectives of teachers. We investigated how teachers and parents in Norway rated sibling mental health to gain a…

Research on siblings of children with developmental and physical disabilities has emphasized negative influences on siblings' mental health. Yet, such siblings may be more prosocial compared with siblings of children without disabilities, due to care responsibilities and their experiences with their brother's or sister's disability. We compared…

This study examines same-sex siblings' educational mobility using high-quality register data from Norway. The study explores how the educational level of younger siblings varies with the education of parents and firstborn siblings. Younger siblings are generally more likely to attain the same education as the eldest. Even though the distance and…

Children with attention deficit hyperactivity disorder (ADHD) often experience co-occurring emotional problems. ADHD with this comorbidity is associated with poorer outcomes than ADHD without comorbidity. Better understanding of the etiology of comorbidity could improve prevention of negative outcomes for children with ADHD. The sample consisted…

Language and sociocultural practices in transnational families have attracted considerable scholarly attention over the last decade. Adding to this research, the present article explores the perspectives of two Polish teenage siblings living in Norway on the projected language and sociocultural practices in their future families. The data for this…

In toddlers, the transition from home to childcare might elicit high levels of the stress hormone cortisol. Measuring cortisol may give an indicator for children's experience and hence, may help improve this transition. We applied linear mixed model analyses to investigate the cortisol levels of 119 toddlers during their transition to childcare…

Studies have identified concurrent, longitudinal, and bidirectional associations between language difficulties and internalizing problems. This is commonly explained by social exclusion or withdrawal from peers, but underlying mechanisms are not well understood. This study uses sibling data to investigate if the comorbidity between language…

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…

Associations between maternal reports of hours in child care and children's externalizing problems at 18 and 36 months of age were examined in a population-based Norwegian sample ("n" = 75,271). Within a sociopolitical context of homogenously high-quality child care, there was little evidence that high quantity of care causes…

The aim of the study was to investigate the relationship between the Flynn effect and the effects of age differences between siblings on the intelligence difference between them. In Norway, the secular trends in intelligence-test score means vary both in magnitude and direction. We identified three periods: one period where the mean intelligence…

How do shocks to parental income drive adolescent human capital, such as university attendance, IQ and health? Unexpected changes to family income may have a predictable effect on child adolescent outcomes, by shifting the money parents spend on human capital investments in their children. The extent to which consumers insure themselves against…

This paper uses Norwegian data to estimate the effect of family size on IQ scores of men. Instrumental variables (IV) estimates using sex composition as an instrument show no significant negative effect of family size; however, IV estimates using twins imply that family size has a negative effect on IQ scores. Our results suggest that the effect…

Background: The idea that raising a child with disabilities has a negative impact on the parents' relationship is still widely accepted despite contradictory research findings. This article addresses the impact of raising a child with disabilities on family structure in the present Norwegian context. Method: Family demographics were collected at…

How do families influence the ability of children? Cognitive skills have been shown to be a strong predictor of educational attainment and future labor market success; as a result, understanding the determinants of cognitive skills can lead to a better understanding of children's long run outcomes. This paper uses a large dataset on the male…

The present paper reports the results of a within and between family analysis of the relation between birth order and intelligence. The material comprises more than a quarter of a million test scores for intellectual performance of Norwegian male conscripts recorded during 1984-2004. Conscripts, mostly 18-19 years of age, were born to women for…