The purpose of this paper is to refer to the Lotka-Volterra model (predator-prey) in order to address cognitive functioning and particularly classification as a mental operation. Logistic regression is used and a model is determined for explaining classification functioning in children four years old. Results show evidence pointing to an on linear function of classification. The children’s performance suggests a balance between the number of questions that the child makes and the mental operations that he must display to coordinate such information.