The Relationship Between the Onset of Speech and Intelligence

This paper was suggested because mothers as well as scientific investigators frequently inquire "What is the normal age for speech acquirement and what circumstances determine the early acquisition or retardation of speech?" In order to reply to these questions we asked ourselves "What is the relationship of the onset of speech to intelligence?" Incidentally we were interested in the development of this function in correlation with other static developments of infancy. Our data were procured from the case records on file at the Institute for Juvenile Research in Chicago. These records are the carefully prepared case studies of children referred to the institute for examination. We are greatly indebted to members of the staff for their painstaking labor in collecting from these records the material for this paper. In consulting a voluminous literature on speech acquisition, it was found that opinions differ as to the age at which this function