The document discusses evidence from brain studies that suggests an innate language capacity in humans. It describes research on language localization in the left and right hemispheres of the brain, including studies of aphasia caused by brain damage. Key areas identified as important for language include Broca's area, Wernicke's area, and the arcuate fasciculus connecting them. The concept of a critical period for first language acquisition is also examined through the case study of "Genie".