The data collection startet in 2007 and 995 4-year olds were examined. Data collections have since then proceeded according to schedule with bi-annual assessments, and the 4th round of data collection was finalized before summer 2015 when 702 children and their families participated, i.e. participation rates have been satisfactory, i.e. 70,6% af those originally joined the study and 95% og those who participated in the 3rd round.
We have addressed the question whether early start and long hours in day care could have any socio-emotional consequences for the child in one paper 'Do Time in Child Care and Peer Group Exposure Predict Poor Socioemotional Adjustment in Norway?' (Solheim, E., Wichstrøm, L., Belsky, J. & Berg-Nielsen, T.S., Child Development, 2013). The overall conclusion is that early start (i.e. at age 1-2 years) and long hours do not seem to have any beneficial or detrimental effects. However, early starters had more conflict with their day care teachers compared to those who started later, but it should be noted that this effect was negligible.
Even though there are no overall effects of early day care start, organizational features of the day care might. We have addressed the impact of newer and freely organized child care (basebarnehager) versus traditional organization of child care institutions with respect to behavior problems and relationship with their teacher in 1st grade. First graders who went to open group arrangement in day care had teachers who experienced less closeness to them and the children evinced more behavior problems than children from traditional day care arrangements. Moreover, there is stability in behavior problems from preschool to 1st grade, but to a higher extent among children in open day cares. We have also examined the importance of child care group size on the student-teacher relationship in 1st grade and the level of behavior problems, finding that although a close relationship towards the day care personnel protects against later behavior problems, this was only the case for children in smaller groups (< 15 children).
The relationship between the day care personnel and the child is arguably the most important day-care factor in children's development. The Student-Teacher Relationship Scale is one of the most used instruments for measuring this relationship, and it the paper The Three Dimensions of the Student-Teacher Relationship Scale: CFA Validation in a Preschool Sample (Solheim, E., Berg-Nielsen, T.S., & Wichstrøm, L., Journal of Psychoeducational Assessment) we asked whether this scale also worked with Norwegian children, and whether it was suitable also for preschoolers. The main conclusion was that this scale did a reasonably good job in characterizing the student-teacher relations, but that certain modifications to the Norwegian context should be considered.
Teachers, also day-care teachers, and parents provide surprisingly different ratings of children?s behavioral and emotional problems. Such discrepant views could potentially cause problems in the cooperation between school and home. It is therefore important to delineate which factors contribute to discrepancies versus congruence between teachers and parents. In the article Preschoolers' Psychosocial Problems: In the Eyes of the Beholder? Adding Teacher Characteristics as Determinants of Discrepant Parent-Teacher Reports (Berg-Nielsen , Solheim, Belsky & Wichstrøm, Child Psychiatry and Human Development) we document that the previously noted discrepancy is largest for emotional problems and less so (albeit still large) for behavioral problems. There is more agreement on boys' problems than girls' problems - which have are generally reported to a much lesser extent among day care teachers. If teachers were in more conflict with the child, their agreement with the parents tended to be larger.
We find that bullying and social exclusion also exist in day care. In 5 separate articles we document the effects and predictors of early bullying and social exclusion: Social exclusion in preschool increases the probability of later symptoms of ADHD; This is also the case for aggressive behavior; Whereas bullying increases the risk of developing anxiety disorder; social competence ? which may be seen as the opposite of social exclusion, protects against developing symptoms of depression.
After four decades of research there are few answers to questions pertaining day-care effects on children's development. We argue that there are at least five methodological reasons for this state of affairs - which will be addressed: adequate control for self-selection biases; simultaneous control for quality, type, and quantity of care; differences in day-care organization and quality between countries; lack of prospective studies; not considering for whom day-care may have which effects. In addition, c hildren themselves have never been used as informants and no one have studied whether day-care may alter the rate of serious behavioural or emotional problems.
Firstly we ask if there are unique effects of quality, quantity and type of day-care on childr en's adjustment and competence (a) during the pre-school years and (b) if such effects extend into the first years at school, adjusting for potential selection biases. Secondly, we will investigate for which children there are day-care effects, viz. accor ding to their temperamental characteristics or parental background (i.e. social inequality).
A probability sample of 995 pre-schoolers participates. Children are interviewed concerning relationships with parents, peers and teachers; educational motivatio n; self-esteem, task orientation - and they are tested on vocabulary, intelligence, executive functioning, and attachment. Information on parents' teaching practises, mental health, children's media use, children's mental health, social competence, and te mperament are obtained through interview and questionnaires. Day-care personnel and school teachers provide information on relationship to the child, rating of social competence, and metal health. Leaders of day-care centers provide information on structu ral aspects of the center. Data are supplemented with archival data on test results (language, reading, math) and official registers. Retesting take place every 2nd year.