Assuming that labels describing a victim as a dehumanized entity reduce a harm-doer's control over aggressive behavior, we attempted to examine the effects of such labels on levels of aggression. A one-on-one fighting video game was used in order to conduct this experiment. During the game, 63 male undergraduates exhibited uncomfortable noises to an opponent who was given either a dehumanizing or anonymous label. We predicted that the dehumanizing label would decrease empathetic concern for, and increase both perceptual and outward hostility towards the opponent (this was measured by high levels of noises during matches). To examine the question of whether the dehumanizing label actually lessens aggressive behavior, or in fact motivates aggressive behavior, we compared the effects of the label on levels of aggression observing whether the opponent showed hostile behavior or not. The results partially-supported our hypothesis. Although the dehumanizing label did not directly increase aggression, further analysis showed that it indirectly increased aggression by lowering empathetic concern for the opponent. Similarly, our results suggested the possibility that dehumanizing labels may in fact increase aggressive behavior in people.