The aim of the paper is to investigate, from the point of view of philosophy of science and philosophy of social science, the turn in the ape language project as accomplished in the works of Sue Savage- Rumbaugh and her collaborators. In this project took place a highly interesting turn from the orientation of research on natural sciences to that on humanities. We shall analyze all the relevant works of Savage-Rumbaugh from the point of view of the two central levels (...) of ALP: its scientific level and the methodological level. (shrink)