Yep the whole animism caboodle has stones as having souls but specifically the souls of the ancestors is I believe less common than other suggestions i.e dancers , maidens , fiddlers .It has become a common approach in the past thirty years to explain the thinking of , particularly , Neolithic peoples building of monuments i,the source is not local folklore as you suggest but thsoe of madagascar , it may well have been the case but it's purely theoretical and when we have sufficent info i.e good dates for the construction and the date of death on the deposits the ancestral idea wears a bit thin as the deposits are shown to be not much older than the people who did the depositing .