Aggression is a heterogeneous, multifaceted construct involving different psychobiological mechanisms and phenomenological manifestations, and influenced by external and socio-cultural factors. The present study examines reactive and proactive aggression in Uruguayan children and adolescents from different socioeconomic contexts. To this end, 643 subjects of both sexes, aged between 8 and 21 years, completed the reactive-proactive aggression questionnaire (RPQ; Raine, Dodge, Loeber, Gatzke-Kopp, Lynam, Reynolds, Shouthamer-Loeber, and Liu, 2006). The results showed that: a) there was an increase in the disposition to reactive, emotional and impulsive aggression from childhood to adolescence; b) both forms of aggression were more frequent in boys during childhood and adolescence, and c) no significant differences were noticed in relation to the socioeconomic status of the groups studied. These findings suggest the advisability of designing programmes aiming at early prevention and treatment of aggressive behaviour, focusing mainly on male subjects and including all social strata, with the objective of reducing subsequent aggressive tendencies in youth and adulthood.
KEYWORDS: reactive aggression, proactive aggression, childhood, adolescence, sex, socioeconomic status, Uruguay.