I made the order-of-magnitude estimate that England used to have about 1: 10,000 potenital geniuses (and about a tenth of these fulfilled their potential).
This number is very approximate, but seems about right.
Let's assume so.
My next conjecture is that behind each of these one-in-ten-thousand potential geniuses were about a hundred creative sub-geniuses - who could make useful innovations in small ways.
So that, in a highly selective institution like one of the old grammar schools or universities, which took only the top few percent of males, there would be as much as 1: 100 potential creative sub-geniuses - and an even higher percentage among their teachers.
The characteristics of sub-geniuses are the same as full genius only less so: they are intelligent, but maybe only in the top ten percent rather than one percent; they have the creative type personality moderately high in Psychoticism (associative thinking, autonomy), but maybe sub-optimally - too conscientious or too lazy, too sociable or too psychopathically-selfish.
These creative sub-geniuses are only to some smallish extent the understanders and spreaders of full genius - because that role can be accomplished by un-creative people (and societies).
But they mostly make quantitative improvements in their specialized activities.
Whatever job they do, whether it is woodwork, medicine, engineering, science, visual art, musical performance, teaching - the creative sub-genius will be pressing towards different and better ways of doing it.
Of course, more often than not, different will turn out to be worse rather than better - nonetheless it is from this group that innovations come or not at all.
Most people will follow a routine as they first learned it, repeating it perhaps several times a day, but never trying to understand and improve it, nor to streamline it.
Only about one in a hundred people will notice (or try to discover) possible ways in which things can be improved. And of course, they may be prevented from trying out the improvement, or their results may be ignored.
But at a frequency of 1:100 - and higher in more skilled and selective areas - sub-geniuses had a considerable social impact. They were, in fact, the 'local' geniuses, the only genius-type people that most people ever encountered.
Nowadays (due to decline in intelligence) their frequency has declined by at least an order of magnitude, and furthermore they are actively selected-against - such that they are invisible, ignorable, powerless and diluted-out.
This is another significant factor in the decline of innovation and capability in The West.