The objective of this study was to investigate the relevance of Loevinger's perspective of psychosocial development for the explanation of misbehaviour and delinquency next to Gottfredson and Hirschi's theory of self-control. General questionnaires about daily life, school, parents, problem behaviour and various other topics were administered to approximately 800 students (12-13 years old) from secondary schools, who also completed a sentence completion test, the ZALC (based on the WUSCT, a test developed by Loevinger). Results indicated that low self-control was associated with misbehaviour and delinquency, and also that being in or between the impulsive and self-protective developmental level was associated with misbehaviour. The developmental level of respondents was also associated with level of self-control. Analysis of covariance showed separate effects of being in the self-protective level on moderate and total misbehaviour beyond low self-control. The results indicate a potential additional importance of psychosocial development in childhood and adolescence for the explanation of misbehaviour and delinquency. © 2008 Taylor and Francis.