Whereas children are physically less affected by the COVID-19 disease, dealing with lockdown may have negative effects on their wellbeing. At the same time, the lockdown might also have positive effects for families, as it might facilitate parent-child bonding. One important factor that may influence the direction of these effects is perceived stress in children and parents. Using a longitudinal twin design, we investigated how perceived stress influenced COVID-19 lockdown induced changes in wellbeing of parents (psychological symptoms and overreactivity) and children (internalizing and externalizing behavior). A total of 106 parents and 151 children (10-13-year-old, 47% girls, majority middle-high SES and Caucasian) enrolled in the longitudinal L-CID study filled in questionnaires during lockdown and data were combined with data of previous years. We report a significant increase in parental psychological symptoms and a decrease in parental overreactivity across time. Longitudinal child measures showed a decrease in internalizing and externalizing behavior, which seemed decelerated by the COVID-19 lockdown. Perceived stress was a significant mediator of changes in parental psychological symptoms: Parents who reported more psychological symptoms prior to the lockdown experienced more stress during the lockdown, which in turn was associated with an increase in psychological symptoms. Similar results were found for children’s externalizing behavior. Results further showed that perceived stress in children was associated with negative coping strategies, parental overreactivity and parental psychological symptoms. These results suggest that children in families with (a history of) parental psychological symptoms and overreactivity might be at risk for negative consequences of the COVID-19 lockdown.

Prior studies have indicated that prosocial behavior might be a protective factor for developing internalizing and externalizing behavioral problems. However, little research has been conducted on within-person changes of prosocial behavior and behavioral problems over time. With random-intercept cross-lagged panel models (RI-CLPMs), the current study analyzed longitudinal associations between prosocial behavior and behavioral problems in two twin cohorts (98% Western European): in early childhood (age M = 4.77, SD = .58, 52% girls, N = 440) and middle childhood (age M = 7.94, SD = .67, 51% girls, N = 512). To obtain robust results, two parental reported questionnaires and an observational task were used as prosocial behavior assessments. In line with the literature, we found a significant between-person association between externalizing behavior and parent reported prosocial behavior in middle childhood, but not in early childhood. Some evidence indicated that changes in externalizing problems affect later prosocial behavior in middle childhood. Overall, however, the RI-CLPMs provided most support for the hypothesis that within-person changes in prosocial behavior are not related to within-person changes in behavioral problems. Thus, our findings did not support the hypothesis that increased prosocial behavior directly results in decreased behavioral problems, but emphasizes the need to take into account the multifaceted nature of prosocial behavior.