To Örebro University

More than half of known crime is committed by 5-6% of the criminal population. Who are these people? Research has shown that it is likely that a majority of these individuals are characterized by having a psychopathic personality. Interestingly, research has shown that psychopathic features are not unique to adults. Youths with high levels of psychopathic traits resemble adult psychopaths in that they are the most frequent, severe and aggressive, delinquent offenders. There is less knowledge, however, about the development of these traits in adolescence, and many fundamental questions have yet to be addressed. The aim of this dissertation is to begin to examine a few of these questions, such as: a) the role of parents andtheir behavior in the development of psychopathic personality in adolescence; b) patterns of stability and change in psychopathic traits during adolescence; and c) whether or not subgroups of adolescents with high levels of psychopathic traits can be identified in a normative community sample. Overall, the results reveal that a psychopathic personality profile characterizes a small group of youths at particular risk of negative development. This group, as well as showing high levels of psychopathic traits throughout adolescence, report high levels of delinquent behavior, and also experience dysfunctional relationships with their parents. Further, the results reveal important subgroups of adolescents with high levels of psychopathic traits, much in accordance with the literature on adult psychopaths. Whereas one group expresses the personality style of primary psychopaths, another is more aggressive, impulsive, and anxious than the other. Taken together, the results of this dissertation suggest that some adolescents are at particular risk of future negative development. Implications for theory and practice, and for the directions of future research, are discussed.