Young populations, and particularly young males, have been attributed a proclivity to aggression and unrest that puts societies at risk. Theories about the dangers of a demographic 'youth bulge' inform public and policy debates about the predictors of violent conflict, as evidenced most recently in the World Bank's World Development Report for 2007. This paper evaluates the validity and utility of claims linking youth bulges to civil conflicts by reviewing different literatures concerning naturalist ideas of young humans' innate aggression and cognitive incompetence as well as environmentalist ideas of environmental stimuli, processes of socialisation, and the dialectical relationship of structural conditions and human agency.

This review finds that the moral panic propagated by youth bulge theorists is too often based on only one form of influence on human development and action, whether an aspect of environment, personal experience, or individual traits. A more cogent analysis must integrate the highly complex and dynamic processes involved in cognition and behaviour and aim to develop theories that take account of the social power, ideational and structural forms, and emotional and cognitive processes that young people experience and draw on in times of war. Theories of causality that fail to account for this complexity obscure understanding of the many ways in which young people and conflict may be linked.