 Correlations have been shown between these factors in a number of experiments; however, correlation does not imply causation.Most experiments involving the relevance of brain size to intelligence hinge on the assumption that complex behavior requires a complex (and therefore intelligent) brain; however, this connection has not been consistently demonstrated.The surface area of a cat's cerebral cortex is approximately ; furthermore, a theoretical cat weighing has a cerebellum weighing , 0.17% of the total weight.