The Origin Of The Notion Of A 'Language Organ'

The notion of a 'language organ' derives from the field of phrenology, a pseudoscience primarily focused on measurements of the human skull, based on the concept that the brain is the organ of the mind, and that certain brain areas have localised, specific functions or modules.

https://www.questia.com/magazine/1G1-155404357/phrenology-and-language