The purpose of the present study was to examine similarity in demographic, behavioral, academic and social attributes as descriptors and predictors of children's friendships. The characteristics of all possible pairs of unique classroom dyads (N = 4725) were used to predict reciprocated school, home and best friendship choices among 554 third (M = 9.38 years old) and fourth ( M = 10.47 years old) graders. Peer reports of aggressive and withdrawn behavior and sociometric status, teacher reports of poverty, and archival reports of sex, race and academic achievement were obtained. The main finding was that as similarity increased, the likelihood of being friends also increased. Specifically, patterns of gender, race, poverty, aggression, withdrawn behavior, achievement and sociometric status between dyad members were descriptive and predictive of children's friendships.

The relative contributions of aggression and victimization to the prediction of self‐reported emotional and behavioral difficulties over and above self‐reported prior problems were investigated in a 1‐year longitudinal study. Fourth‐, fifth‐, and sixth‐graders (N = 471) completed peer nominations of aggression and victimization as well as self‐report measures of social, behavioral, and emotional problems at baseline and at 1‐year follow‐up. Peer aggression added to the prediction of externalizing problems, specifically, self‐report of aggression and delinquency. In contrast, victimization by peers contributed to self‐reported unpopularity but not depression. Victimization among girls was also predictive of subsequent self‐reported delinquency. Theoretical and practical implications of the findings, as well as future directions for research, are discussed. Aggr. Behav. 26:345–358, 2000. © 2000 Wiley‐Liss, Inc.