Many contemporary theorists believe serotonin (5-HT) neurotransmitter
functioning plays a role in the regulation of human aggressive behavio
r. We argue that the evidence supporting this 5-HT hypothesis of human
aggression is less compelling than commonly assumed, due to (a) confl
icting study results, and (b) significant methodological limitations o
f existing studies. Recent models that integrate the role of psycholog
ical and contextual variables in 5-HT-associated aggression are review
ed. The need to incorporate psychometrically sound measures of aggress
ion in 5-HT studies, to use experimental and longitudinal designs, and
to test hypotheses draw from multifactorial models in future research
is advocated. (C) 1997 Elsevier Science Ltd.