Learning and Individual differences in Aggressive Behavior Observed in Rats that Have Lived in Small Mixed Colonies

Abstract

An experiment was performed to determine the relationship between open field measures (ambulation and defecation) and aggressive behavior in laboratory rats. Learning influences over this relation were considered. Colony-maintained laboratory procedure was not effective to increase

the aggresive behavior of animals when un intruder rat was placed into the colony. In the subjects not exposed to prior attack conditioning the classification variables ambulation and defecation were not enough important to determine or influence the aggression level. Nevertheless, the observed tendency was that the rats with high ambulatory scores were more aggressive than the low ones, and the rats with low defecation scores were more aggressive than the high ones. In the subjects exposed to prior attack oonditioning the Subjects with high ambulation and high defecation scores were the more aggressive. Then, these Subjects learned more quickly than the low ambulation and defecation ones.