The stage of development of a species predicts the number of neurons

Abstract

Does the complexity of an organism’s behavior predict the number of neurons in an organism’s brain? In the model of hierarchical complexity, the behavioral stage of any organism can be assessed. These behaviors fall into discrete stages. The behavioral stage of development of an organism is defined by the highest order task that an organism has been observed performing. In this study, literature was reviewed to find animals where a neuron count had been taken, and to find behavioral studies to score for stage of development. Once those determinations were made, a power regression analysis addressed the question of whether the behavioral stage of development at which a species operating at predicts the number of neurons an organism has. The relationship between these two variables was r (17) = 0.874. These findings imply developing to the next higher stage requires an increase in the number of neurons a species has. The evolutionary benefit from a species evolving to have more neurons may be driven by reinforcement contingencies in the environmental niche that species occupies. If these reinforcement contingencies are one order of hierarchical complexity higher than the stage the species operates at, then the species must increase the number of neuronal connections; this increase reaches a maximum dictated by the number of neurons, so there is a time when the species must evolve more neurons. to perform the comparatively more hierarchically complex tasks required to attain new reinforcement. Therefore it is the attraction of higher stage reinforcers that drives neural development. This neurological correlation for behavioral complexity shows that there is a countable amount of processing power that limits the rate of stage change in a lifetime. The accuracy with which stage of development predicts the number of neurons cast behavioral development as a driving force in neuronal evolution.