Both captive and wild chimpanzees can make and use crude tools. Evidence is cited that chimpanzee tool use depends as much on their faculty for manipulating and relating to objects as on their high intelligence. Even early in life, this faculty is clearly evident, and infant chimpanzees, raised in nurseries under conditions similar to those for human infants, develop transitional object relationships identical with those seen in human infants. It is hypothesized that, in the evolution of man, object manipulation and relationships preceded tool making and tool use as a transitional step. Gradually, protohominids learned to manipulate objects in order to interact or manipulate other objects. The use and modification of these primitive tools was learned by cohabitants through imitation, thus becoming part of the learned behavior and tradition of the protohominid culture.
Kollar EJ. Object Relations and the Origin of Tools. Arch Gen Psychiatry. 1972;26(1):23–27. doi:10.1001/archpsyc.1972.01750190025006