The Girls United study: Examining the association between elementary schoolgirls’ friendship dynamics and their social, emotional, and academic development.

Dutch elementary school girls are struggling with their mental health. Trend research by the University of Utrecht has shown that internalizing problems among elementary school girls have been doubled between 2017 and 2021, from 14 to 33%. At the same time, the influence of close friends increases during late childhood and early adolescence: self-disclosure, sharing personal thoughts and emotions with peers, becomes an important strategy during this period to regulate one’s own unpleasant and pleasant emotions and thoughts. When self-disclosure escalates into co-rumination, girls are at elevated risk of early onset internalizing problems. In this study, we aim to study daily real time and online positive and negative friendship dynamics among 200 girls’ friendship dyads from 5th and 6th grade. through a smart-phone based diary study (study 1). The second objective is to study co-rumination patterns and to examine its impact on emotional well-being and school-functioning (study 2). Both studies will also study the influence of the home- and classroom context on the abovementioned processes, investigated in study 1 and 2. Both studies aim to include the same N = 200 friendship . This study will be one of the first to include a diary study on friendship dynamics among friendship dyads in late elementary school.