In a study by Azrin et al. (1966), it was found that pigeons attacked other pigeons when the transition from a food reinforcement schedule to an extinction schedule was employed. These aggressive behaviors that appear due to the implementation of an extinction schedule, however, has not been widely studied in the laboratory rat. Examples of the types of phenomena that have been given attention with regard to laboratory rat aggression are male aggression in a mixed-sex colony toward male intruders, attack elicited by the application of aversive stimuli, and female-elicited aggression of male rats living in colonies. The expression of aggressive behaviors in rats appears to be highly responsive to developmental, experiential, and contextual variables. The present study focuses upon aggression displayed toward two characteristically different objects--one a stuffed rat and the other a wood block--when an extinction schedule is employed with laboratory rats. By using an extinction paradigm with rats bar-pressing for food, the present study examines aggression in this context by measuring the intensity and type of aggressive behavior displayed toward the two different objects as well as looking at other behaviors elicited by an extinction schedule.
Rajala '92, Amy K., "Extinction-Induced Aggression in Laboratory Rats" (1992). Honors Projects. Paper 62.