Findings were derived from a larger parent 13-year longitudinal study designed to identify high-risk early signs that a juvenile, already a member of a broader high-risk urban group, is further at risk for delinquency and its related academic and emotional problems. The parent study cohort of 660 children was selected at random from center city Philadelphia kindergarten in the fall of 1968, and a broad range of information has been collected on them since then, including data on delinquency and misconduct, academic performance, special placement, emotional well-being, drug use, and overall behavior adjustment to the school environment. The average age of the cohort at the time of the report writing was 19. The study sought to determine whether behavior emerging during kindergarten and primary school years relative to a child's adaptation to the school environment distinguishes children who may be at risk for subsequent misconduct both in school and the community. The study found the following behaviors to be indicative of subsequent delinquent behavior: (1) the tendency in the classroom to become involved in poking and annoying social behavior, including excessive talking and noisemaking; (2) impatience, reflected in the tendency to rush into things before listening or judging what is best to do; and (3) self-centered verbal responsiveness characterized by interruption of others, irrelevance of what is said in the context of ongoing conversation, and blurting out personal thoughts with insufficient self-criticality. Some implications and explanations of the findings are discussed. About 80 references are provided, and the appendixes contain study instruments and forms.