This paper aims to provide an analysis of principal theories and empirically proven risk and protective factors in the aetiology of violence and aggressive behaviour from the perspective of the Ecological systems theory. The paper is set to review theoretical and empirical findings on key factors in the development of aggressive behaviour. It starts with the individual level (genes, individual traits), across the microsystem and mesosystem (family, school, peers), through the exosystem (community, media, parent’s workplace) only to include the broadest aspect of the macrosystem (culture, norms, governance, war, natural disasters). We present an overview of the most recent research findings on aggressiveness and violent behaviour as an impet...