Aetiology of antisocial behaviour Essi Viding a,b, ⁎ , Henrik Larsson c a Department of Psychology and Institute of Cognitive Neuroscience, University College London, UK b Social, Genetic, and Developmental Psychiatry Centre, Institute of Psychiatry, King's College London, UK c Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Sweden Abstract. In this paper we briefly and selectively review the current knowledge base of the nature and nurture for persistent, early-onset antisocial behaviour, with a particular focus on studies that have examined potential etiologic distinctions such as callous-unemotional subtype of antisocial behaviour. First, we discuss results from recent studies that indicate that callous-unemotional traits can be used to distinguish two different subtypes of conduct problems at a behavioural, cognitive–affective, and possibly neural level. Second, we review genetically informative studies on antisocial behaviour keeping in mind the distinction of callous-unemotional subtype. Data from these two lines of research (i.e., genetic, neurocognitive studies) to date suggest that antisocial children with callous-unemotional traits are genetically more vulnerable to antisocial behaviour than their antisocial peers and that this genetic vulnerability may manifest in a distinct neurocognitive signature. In this paper we also highlight the complex interplay between nature and nurture and provide examples of how putative environmental risk factors for antisocial behaviour can be studied using behavioural genetic research designs. Finally, we give some pointers of new research strategies in the field and draw out implications of this research to practice. © 2007 Published by Elsevier B.V. Keywords: Antisocial behavior; Genes; Serotonin; Callous-unemotional traits 1. Introduction Each year over 1.6 million people are killed through violence [1]. Preventing violence is one of the most important global concerns. The political, social or economic causes of violence are well studied, but more recently the awareness has grown that biological causes, which may explain individual differences in predisposition to violence, also need to be International Congress Series 1304 (2007) 121 – 132 www.ics-elsevier.com ⁎ Corresponding author. Department of Psychology, University College London, Gower St., London, WC1E 6BT, UK. E-mail address: e.viding@ucl.ac.uk (E. Viding). 0531-5131/ © 2007 Published by Elsevier B.V. doi:10.1016/j.ics.2007.07.040