Contingency adduction of "symbolic aggression" by pigeons

THIS STUDY ADDRESSED THE QUESTION: Can novel social behavior arise even though the organism has had no explicit training in that particular social pattern? Seven pigeons were trained individually to peck keys for brief access to food. Four of these birds were also trained to peck two "switching keys" which, at first, raised or lowered the requirements on their own food keys. Later, these switching keys no longer affected an animal's own requirements, but raised or lowered the requirements imposed on a second pigeon working concurrently for food in an adjacent chamber. The second animal was trained only on the food key. In each such pair, the pigeon trained on the switching keys reliably pecked whichever one raised its partner's schedule-requirements. This novel pattern of behavior did not directly benefit the first bird, arose spontaneously as a recombination of previously established nonsocial repertoires, and seemed to be maintained entirely by its effects on the animal in the adjacent chamber.