The manifest power of a general notion (not its meaning) as a class that binds together individuals is in fact contrary to the common empirical explanation of its birth.
Thus, though it is explained by the progressive accumulation of similar characteristics, it preserves itself as a functional notion by an implicit agreement that the involved individuals are worthless and do not deserve much attention.
We talk about dogs, numbers, or human beings by assuming that none of them is actually worthy of being considered in its individuality.
If we imagine the process of generalization as one that is proposed by identifiable speakers, then we could clarify which are their interests in neglecting certain particulars.
Though such an inquiry is almost impossible to be done, its omission should not stop us to question about their human origins of at least those general notions that conspicuously affect the common attitude to the individual things and persons.