Childhood aggression has also been associated with injury among adolescents. Cobb, Cairns, Miles, and Cairns (1995) followed 271 children from either the 4th or the 7th grade through ages 14 to 18 years. The participants were from one suburban-metropolitan area and one rural area, were 48% male, and were 23% African American and 76% Caucasian American. Aggressive behavior, as reported by the participants' teachers in the 4th or 7th grade, predicted overall injury occurrence over the course of the study. Childhood aggression was also associated with the risk of "close-calls", or cases in which a potentially injury-producing incident almost occurred. This result may be related to the finding that school discipline problems predicted injury among the rural participants in the study by Alexander and colleagues (1992), described above.