Research in animals has only recently been successful in reliably mimicking the long-established link between alcohol and heightened aggressive behavior. The present review highlights the large individual differences in the effects of acute low alcohol doses on aggressive behavior in rodent and primate species, paralleling the human condition. Subpopulations of both species show reliable and repeatable enhancement of aggressive behavior when administered low, acute alcohol doses. Statistical analysis of the temporal patterns of aggressive behavior indicate that alcohol prolongs aggressive bouts or "bursts" and increases the number of aggressive behaviors within each burst. However, the latency to initiate attack and the time between aggressive bursts are relatively unaltered by alcohol. These alcohol-induced increases in aggression can be potentiated by benzodiazepine agonists and prevented by antagonists. In addition, highly aggressive animals can be differentiated from nonaggressive ones at the GABAA-benzodiazepine receptor complex. These data suggest an important link between alcohol, aggression and the GABAA-benzodiazepine receptor complex.