Children's early aggressive behavior and rejected peer status are both known to predict serious maladjustment later in life. The primary goal of this study is to examine whether emotional factors play an important role in the early development of these patterns. Specifically, how are children's emotion recognition skills and their spontaneous emotion displays related to the frequency of various types of conflictual behaviors and children's peer status? Approximately 60 4- 5-year-old children enrolled in 4 separate classes in one preschool will participate. Naturalistic observations will be conducted using focal- event sampling techniques with each child observed for a total of 6 hours: 3 hours for recording aspects of conflictual behavior including type of episode (e.g., aggressive vs. non-aggressive, reactive vs. proactive, etc.), conflict role (initiator vs. recipient), and other issues using a checklist instrument; and 3 hours for recording naturally- occurring conflict and non-conflict emotions using a live-action coding system. In addition, 2 individually administered interviews will be used to assess: a) each child's ability to recognize facial emotions and judge the likely emotional outcomes of social vignettes; and, b) each child's peer status based on sociometric nominations. Finally, observational assessments of aggressin will be supplemented with peer and teacher assessments of aggression. In general, it is expected that negative peer status nominations will be associated with deficits in children's emotion-related abilities, negative mood states, frequent conflict emotions, and higher rates of conflictual behavior. Specific inter- relationships, however, will vary depending on the type of conflictual behavior. For example, reactive (retaliatory) aggression, but not proactive (instrumental and dominating) aggression will be associated with emotion recognition deficits. Overall, aggressive behaviors will be linked with negative peer nominations, but additional non-aggressive behaviors including frequent non-aggressive conflicts, and negative moods are also expected to be associated with negative peer nominations. This study should provide needed information about how children's emotions and emotion-related abilities are linked with their conflictual behaviors and peer status.