Variation in lateralization: Selected samples do not a population make

Abstract

The two major points of Denenberg's article are (1) that animals have lateralized brains, and (2) that the pattern of cerebral lateralization is consistent across species (i.e., “the left hemisphere will be primarily involved in communicative functions,” the right hemisphere with processing “spatial and affective information.” In addition, there is an unstated assumption that the pattern of lateralization is consistent within species. The evidence reviewed by Denenberg leaves little doubt that nonhuman animals have asymmetrically organized brains. However, there are problems with the suggestion that there is a consistent pattern of cerebral lateralization within or across different populations of species.