The scientific literature indicates that the majority of adolescents have committed one or two offences in the past. However, most of the offences committed involve petty crime. The main questions that this study addresses are: why is there an increase from early to middle adolescence in the number of adolescents who engage in delinquent behaviour, and why is there a decrease from middle to late adolescence? According the Hirschi's social control theory (1969) delinquent behaviour varies as a function of social bonds. In contrast, the hypothesis here is that in the period from early to middle adolescence the chance of taking up delinquent behaviour increases as a result of the restraining bonds with conventional persons and institutions. To test this theoretical framework, two sources of information are used: the Utrecht study of adolescent development (USAD) and the Study of social behaviour. The USAD sample contained 3,393 adolescents of 12 to 24 years of age. The sample for the study of social behaviour included 852 pupils from Dutch urban high schools between 15-17 years of age. A multi-group LISREL analysis was used to test the hypotheses. The results lead to rejection of the first hypothesis. In the period from early to middle adolescence more relational exploration did not result in more delinquent behaviour. However, the characteristic increases in delinquent behaviour during this period was not caused either by weaker bonds with parents, school/work, less disapproval of delinquent behaviour or a stronger bond with friends. There was a long-term effect (from 1991 to 1994) in the opposite direction. Specifically, more delinquent behaviour led to weaker bonds. The second hypothesis is that in the period from middle to late adolescence stronger bonds with conventional persons and institutions lead to less delinquent behaviour was confirmed. That is, stronger bonds with parents and school/work led from middle to late adolescence to less delinquent behaviour. Subsequently, this delinquent behaviour led in ...