Development and Psychopathology

Regular Articles

The snowball effect: Friendship moderates escalations in depressed affect among avoidant and excluded children

William M. Bukowskia1 c1, Brett Laursena2 and Betsy Hozaa3

a1 Concordia University

a2 Florida Atlantic University

a3 University of Vermont


A three-wave longitudinal study conducted with preadolescent boys and girls (N = 231 at Time 1 [T1]) was used to assess the hypotheses that aspects of social withdrawal would be predictors of a “snowball” cascade of depressed affect, and that friendship experiences would moderate these effects. Consistent with these hypotheses, multilevel modeling showed that measures of avoidance and exclusion at T1 were associated with concurrent levels of depressed affect and were antecedent to escalating trajectories of depressed affect over time. These accelerating growth curves fit a snowball cascade model. The analyses also showed the protective effects of friendship. Specifically, the snowball effect was limited to avoidant and excluded children who were friendless. Depressed affect did not increase among avoidant and excluded children who were friended.


c1 Address correspondence and reprint requests to: William M. Bukowski, Concordia University, Department of Psychology and Centre de Recherche en Développement Humain, 7141 Rue Sherbrooke Ouest, Montreal, Quebec H4B 1R6, Canada; E-mail:


The order of authorship for the first two authors is arbitrary; each made equal contributions to the project. Funding for this study was provided by the Social Sciences and Humanities Research Council (SSHRC) of Canada, by the W. T. Grant Foundation, and from a Concordia University Research Chair (all to W.M.B.) and by National Institute of Mental Health Grant MH58116 and National Science Foundation Grant 0923745 (to B.L.).