Normal students develop a network of social ties throughout their schooling, but students who perform poorly or drop out fail to develop that rapport. According to the theory of social vulnerability, these latter students are more prone to juvenile delinquency because of the absence of significant social ties. The author conducted a questionnaire survey of 1,689 students in their first, third, and fourth years of vocational schooling and of 258 of their teachers. The results indicated that students who had frequent brushes with the police and criminal justice system also experienced behavioral problems at school. In particular, a statistically significant link emerged between student problem behavior and negative instructor attitudes. The study concludes that the school and the teacher-student relationship have a crucial impact on juvenile behavior. A bibliography is included.