Objective The aim is to investigate if young children with developmental and behavioral difficulties (DBDs) have greater risk of peer-victimization compared with typically developing (TD) children. Method The sample was drawn from the Norwegian Mother and Child Cohort Study (MoBa). MoBa has collected population-based data on children's health and development for 114,500 children. We included children that were 5 years of age (n ¼ 41,609). Multivariate logistic regression was used to estimate the effect of different DBDs and of co-occurring DBDs on peervictimization compared with TD children. Categories of DBDs included autistic traits, emotional difficulties, behavioral difficulties, general learning difficulties, attention difficulties/impulsive behavior, motor development difficulties, language difficulties, and hearing and vision difficulties. Results were adjusted for socioeconomic status and the child's sex. Results Peer-victimization was 2.8% (933) among TD children, and 8.0% (615) among children with DBD. The highest risk of peer-victimization was found among children with autistic traits and children with five or more cooccurring DBDs (adjusted odds ratios [ORs] ¼ 12.76; 95% confidence interval [CI] 8.64-18.84; p .001) and 17.37 (95% CI 12.15-24.82; p .001)], respectively. The lowest risk was found among children with hearing and vision difficulties and children with only one DBD [adjusted ORs ¼ 1.98 (95% CI 1.71-2.29; p .001) and 1.95 (95% CI 1.70-2.22; p .001)]. Conclusion Children with DBD have a substantially higher risk of peer-victimization compared with TD children. Peer-victimization varies with type of DBD and increases cumulatively by number of DBDs.

Background and Purpose Schoolchildren with language difficulties experience more peer victimization compared to their typically developing (TD) peers. Whether these children also bully their peers (bully perpetration) more than TD children is unclear. Furthermore, little is known about peer victimization and bully perpetration among preschool children with language difficulties and how it may be related to different paths of language difficulties. This study aimed to investigate associations between language difficulties, peer victimization, and bully perpetration from preschool to school age as well as the risk of peer victimization and bully perpetration for children with different developmental paths of language difficulties and mild language difficulties compared to TD children. Method The sample was drawn from the Norwegian Mother, Father and Child Cohort Study. Participants with completed questionnaires at 3, 5, and 8 years of age ( n = 22,628) were included. Paths between latent variables of language skills at 3, 5, and 8 years of age, peer victimization at 5 and 8 years of age, and bully perpetration at 8 years of age were examined with structural equation modeling. Logistic regression was used to investigate peer victimization and bully perpetration for predefined paths of language difficulties. Results Poor language skills at 3 and 5 years of age were associated with peer victimization at 5 years of age. Poor language skills at 5 and 8 years of age were associated with peer victimization and bully perpetration at 8 years of age. The association between poor language skills at 5 years of age and bully perpetration at 8 years of age was stronger for girls. Persistent paths of language difficulties at 3, 5, and 8 years of age showed the highest risk of peer victimization and bully perpetration. Conclusions Language difficulties are associated with peer victimization and bully perpetration. The risk of peer victimization and bully perpetration differs according to different developmental paths of language difficulties from preschool to school age.

Background Children with poor motor skills are at increased risk of peer victimization. However, it is unclear whether poor gross and fine motor skills are differently linked to peer victimization among pre‐school and schoolchildren. Aims To investigate associations between poor gross and fine motor skills measured in pre‐school and the associations to peer victimization measured concurrently and in school age. Sample Data from the Norwegian Mother, Father and Child Cohort Study (MoBa), and the Medical Birth Registry of Norway were used. Participants with complete questionnaires at 3, 5, and 8 years (n = 23 215) were included. Methods A longitudinal design and an autoregressive cross‐lagged model were used to investigate if poor gross and fine motor skills at 3 and 5 years predicted peer victimization at 5 and 8 years. Because emotional difficulties are associated with both motor skills and peer victimization, the results were adjusted for emotional difficulties. Results Only poor fine motor skills at 3 years had a significant association to peer victimization at 5 years. Poor gross motor skills at 5 years had a stronger association to peer victimization measured concurrently compared to poor fine motor skills, and only poor fine motor skills at 5 years was significantly linked to peer victimization at 8 years. No gender difference was found between these paths. Conclusions Teachers and parents should be aware that motor skills predict peer victimization, and that poor gross and fine motor skills have different associations to peer victimization measured at different ages.