The present study examined the behavioral and affiliative differences between 2403 fifth grade students (1307 female, 1096 male) who reported that they belonged to a social group on social cognitive map (SCM) procedures and those who did not even though their peers viewed them as members of a peer group. Students who did not report their affiliations were more often classified as victims of bullying, have lower peer preference, have more peer-assessed internalizing symptoms, and have lower prosocial behavior and social prominence than students who reported their peer affiliates. Females with higher self-reported levels of aggression were more likely to report their peer affiliations. Males with higher self-reported levels of internalizing symptoms were less likely to report their affiliations. Implications and future directions are discussed.