Antisocial behaviour is a substantial problem in Europe: detrimental to victims, the youth, families and society as a whole. Among promising research avenues are the use of genetically informative longitudinal studies, as well as research designs aimed to determine which predictors of antisocial behaviour are causative. Using such innovative designs, my primary purpose is to provide a better understanding of the development of antisocial behaviour from early childhood to adolescence and its predictors, which will help to identify important targets for intervention and will provide an indication of when best to intervene.<br/>I will use the Twins Early Development Study (TEDS), a unique data set of 10000 pairs of twins born between 1994 and 1996 and followed from 2 to 16 years. The present project comprises 3 complementary objectives: (1) identify childhood disorder symptoms uniquely predicting adolescent delinquency and identify the genetic and environmental contribution in the prediction; (2) verify whether harsh parental discipline and peer victimization play a causal role in the prediction of antisocial behaviour; (3) determine at which age and for which populations (e.g. disadvantaged populations) heritable or environmental components play a greater role in antisocial behaviour. I will use advanced statistical modelling, namely by combining twin modelling with propensity score matching. The present project will generate new knowledge with both innovative techniques and a data set of unique quality. As such, the project is both innovative and timely.<br/>So far, I have received interdisciplinary training in a world leading research team specialising in antisocial behaviour, which has resulted in high impact publications. With the proposed fellowship, I will benefit from outstanding specialised training and mentoring, which will be crucial to establish myself as an independent researcher and contribute to the excellence of the European Research Area.