Abstract
Attack behavior was elicited from squirrel monkeys by externally applied electric shock. The shock elicited attack toward other monkeys, rats, and mice, as well as toward inanimate objects, such as a stuffed doll, and even a round ball. A method of quantifying the attack behavior was devised on the basis of the attack against inanimate objects. This method revealed that the duration and probability of attack was a direct function of the shock intensity.