Unpacking early risks for peer victimization: A network analysis of early temperament and polygenic risk scores

Background Children who show difficult temperament are at risk of peer victimisation, which in turn associates with numerous negative outcomes later in life. We used network analysis to examine whether specific aspects of difficult temperament contributed to these associations, and whether the links were moderated by variations in genetic liability for ADHD, schizophrenia, and depression.Methods In 3354 mother-child dyads (51.8% female), we examined in three steps: (i) the network structure of difficult temperament as indexed by adaptability, intensity, and mood (age 2), (ii) its item-level associations with peer victimisation (ages 8, 10, and 13), and (iii) moderation of these associations by polygenic risk scores (PRS) for ADHD, schizophrenia, and depression.Results Indicators of difficult temperament formed a coherent network that was associated with peer victimisation. Regarding PRS moderation, for those high in PRS (top 10%) for ADHD and schizophrenia, indicators of temperamental intensity and mood were associated with peer victimisation, respectively. For those high in PRS for depression, however, aspects of temperament were no longer associated with peer victimisation. Finally, the network results for those in the general population across all PRS (bottom 90%) largely resembled the model estimated using the full sample.Conclusion The findings highlight specific temperamental behaviours as risk factors for peer victimisation; additionally, children high in PRS for neurodevelopmental disorders may be at especially high-risk for this outcome early in development.