Early Education & Development Volume 16, Number 2, April 2005 Relational Aggression and Friendship During Early Childhood: “I Won’t Be Your Friend!” Jean E. Burr 1 , Jamie M. Ostrov 2 , Elizabeth A. Jansen 1 , Crystal Cullerton-Sen 1 and Nicki R. Crick 1 Institute of Child Development, University of Minnesota 1 University at Buffalo, The State University of New York 2 Associations between relational aggression and mutual, dyadic friendships during early childhood were assessed in the context of a year-long, short-term longitudinal study. Children’s mutual friendships were determined via sociometric ratings and their relationally aggressive behavior among peers was assessed via naturalistic, free play observations. Generally, children who were more relationally aggressive had more mutual friends, although this relation differed by gender and time of assessment. Future work should include measures of friendship quality and investigate the role of relational aggression within friendship dyads. Support for this project was provided by NSF (BCS-012651) and NIMH (MH-01-002) grants to Dr. Nicki R. Crick, the Lois Cram Babcock Scholarship in support of the first author, and an NIMH traineeship (MH- 15755) to the Institute of Child Development in support of the second author. We thank Alison Eudeikis, Peter Ralston, and many undergraduate research assistants for their invaluable support with this project. We are also grateful to the directors, teachers, and families who participated in the Preschool PALS Project. We thank Samantha Senich for her assistance with coding and her comments on an earlier version of this manuscript. We also acknowledge Dr. Susanne Denham and the 3 anonymous reviewers for their helpful comments and suggestions. Correspondence concerning this manuscript should be directed to Jean E. Burr, Institute of Child Develop- ment, 51 East River Road, University of Minnesota, Minneapolis, Minnesota, 55455 (Phone: (612) 624- 3347; Fax: (612) 624-6373; E-mail: burr0109@umn.edu).