While much is known about the environmental and interpersonal factors
which lead to impulsive aggression, it is now possible to examine biol
ogical vulnerabilities to such behavior. Studies of biology of impulsi
ve aggression in animals and humans have implicated abnormalities in v
arious systems, for example, serotonin, norepinephrine, sex steroids,
and vasopressin. This article reviews the role of abnormal neurobiolog
y in the vulnerability to impulsive aggression and suggests areas for
further investigation.