Humans can personally know at most roughly three or four thousand people

Evidence

First, and probably most obvious, there would appear to be a sheer biophysical/imitation on the capacity of human beings to recognize, either by name or by face (i.e., to have personal knowledge of), an infinite number of their fellowmen. I know of no research which tells us the maximum numbers that can be known; human beings probably vary in their individual capacities in this regard.lO My own guess -and it is only a guess-is that the maximum number might be three or four thousand, perhaps slightly more. — Lyn H. Lofland, World of Strangers_ Order and Action in…, 76

Categorization

• QUESTION: Is there real research on the biographical limit of personal acquaintance? Dunbar’s number offers a much lower figure worth reconciling with this guess.