"Darwin is most probably right from his own point of view, i.e., in the sense that in the notorious 'nature of man' we cannot find a single feature not seen first in some species of animal, and that for this reason, we have absolutely no grounds for designating man as some kind of unique creature, or, in other words, for placing him in a special 'kingdom'."
However across different species some features more than others are more disproportionately augmented. In humans memory is one such feature that has been historically developed along with the prefection of auxiliary means that social humans have worked out in the process of their cultural life. As Vygotsky point out, human memory is perfected in as much as systems of writing - systems of signs and their usage. Vygotsky and his marxist contemporaries i.e. Plekhanov were keen to point out that the development of human memory became subject to external forces with the development of writing, and thus driven by changes in human culture. This drive is realized as a reason for the distinction between thel memory in primitve and modern humans. The distinction being the natural eidetic memroy of primitive humans as compared to the mnemonic memory of modern humans. As though the development of writing freed huamn memory from the perceptual load of the environment in primitive cultures, thereby affording modern humans the capability to more readily utilize symbols in manipulating and abstraction of ideas.