There used to be and to some extent still is a feeling among linguists that the psychology of a language is more particularly concerned with its grammatical features, but that its sounds and its phonetic processes belong to a grosser physiological substratum. Thus, we sometimes hear it said that such phonetic processes as the palatalizing of a vowel by a following i or other front vowel (“umlaut”) or the series of shifts in the manner of articulating the old Indo-European stopped consonants which have become celebrated under the name of “Grimm's Law” are merely mechanical processes, consummated by the organs of speech and by the nerves that control them as a set of shifts in relatively simple sensorimotor habits. It is my purpose in this paper, as briefly as may be, to indicate that the sounds and sound processes of speech cannot be properly understood in such simple, mechanical terms.

For those psychologists for whom psychology is a study of the conditions known as the cultural status of the individual, or the anthropological status of the group, the study of the language mechanisms is taking on a new aspect. Language as a form of behavior through which the individual adjusts himself to a social environment, is not the same thing as language as a medium of expression of so-called subjective desires, hopes, and aspirations. As a form of behavior, language represents biological, physiological, and social conditions; as a medium of expression, it assumes the existence of non-physical forces or types of psychical energy whose existence has not been adequately demonstrated. Therefore, when the psychologist finds himself confronted with the request to make a “psychological” explanation, or a “psychological” interpretation of a careful and detailed linguistic investigation, he is unable to add anything and if anything is added it often only obscures the investigation.