Kinds of Aggressive Behavior: Part 2 of 3

2. Predatory aggression. Quite different from the aroused state associated with angry aggression is the dispassionate stalking of its prey by a carnivorous animal such as a fox, a wolf, or any member of the cat family.
One would hesitate to call this behavior "aggressive'' and would label it "food-seeking'' instead, were it not for the fact that the hunger drive need not be present-the response seems to be elicited simply by the presence of the prey and may occur even when the predator is totally satiated.

An interesting finding about predatory behavior is that in some animal species it is partly learned through imitation. A kitten learns to kill rats by the age of four months if it is normally reared and allowed to see its mother killing rats. If a kitten is raised in isolation, however, the chances are that it will not kill a rat if it is presented with one when it is four months old. It can soon learn to do so if it is given the opportunity to watch other cats kill (Kuo, 1930).

3. Fear-induced aggression. This is exemplified by the usually meek animal that when cornered by a predator, turns on it and attacks it. More generally, any fearful animal is likely to bite when approached too closely by the object of its fear.

4. Operant aggression. An organism may perform an aggressive act simply because it is rewarded for doing so, or punished for not doing so. For example, the tendency of a rat to attack another animal or an object when it is given an electric shock can be strengthened if the shock is turned off whenever the rat attacks. Human adults (Loew, 1967) and children (Lovaas, 1961) who are praised for making hostile remarks tend to become more aggressive. The hired killer, who kills because he is paid to do so, is a good example of this class of aggression.