Gender differences are evident in the etiology and maintenance of aggressiv
e behavior (which is on the increase for both male and female youths), but
the explanatory models that have been proposed, including social learning t
heory and information processing models, are more appropriate for boys than
for girls. In an attempt to elucidate processes underlying aggression, par
ticularly for girls, the authors explored locus of control as a cognitive v
ariable possibly related to aggressive behavior. The relationships between
teacher-reported aggression and 3 types of locus of control (internal, powe
rful other, and unknown) for success and failure experiences were investiga
ted. For girls, aggressive behavior was positively related to internal and
unknown locus of control. In contrast, boys' aggressive behavior was unrela
ted to internal locus of control beliefs and negatively related to external
locus of control beliefs. Possible explanatory mechanisms for the relation
ship between locus of control beliefs and aggression are discussed. The pre
sent study contributes to the understanding of aggression in girls and poin
ts to different processes underlying girls' and boys' aggression.