Vigotsky on animal learning

In his Mind in Society Lev Vigotsky wrote on animal intelligence that "primates cannot be taught (in the human sense of the word) through imitation, nor can their intellect be developed, because they have no zone of proximal development. A primate can learn a great deal through training using its mechanical and mental skills, but it cannot be made more intelligent, that is, it cannot be taught to solve a variety of more advanced problems independently. For this reason animals are incapable of learning in the human sense of the term; human learning presupposes a specific social nature and a process by which children grow into the intellectual life of those around them."


Vigotsky, Mind in Society (1978), p. 88.


Vigotsky's point raises an interesting question: are primates really unable to develop intelligence, or is the issue rather that since they don't have the kind of social life humans have, they have no motivation to engage in the activities humans try to teach them to engage. A chimpanzee does not apply the basic counting skill it learns from humans more generally. But not because it cannot or could not, but rather because it has no situations in its life where it would need to. As Vigotsky stresses with regards to the development and learning of humans, abilities learned can be very task or domain specific. Why expect them then to generalize better in the case of animals? It would seem to me to be an equally good general and abstract speculative explanation of why animals don't go on using their intellectual skills further, that they lack independent motivation to engage in the tasks that humans usually try to engage them in (e.g. communicating with humans, counting, social cooperation tasks, etc.). This means, that the lack of human-like development is the result of the lack of human-like motivation. This is nothing surprising in species with different life forms from ours.

Of course I know that Vigotsky's point was quite speculative, and mine even more so. I'm more than happy to receive pointers to good data, ideas, and reading suggestions to this.