The industrial revolution (including the agricultural revolution) was a product of genius: that is my contention.
It was a product of a sudden ample supply of geniuses in North West Europe who generates breakthroughs (in the necessary fields) so thick and fast that productivity took-off and out-ran population growth for... well about 10 generations so far.
The breakthroughs came from NW Europe and its diaspora, but spread across the world: the main beneficiaries were the poor (although you'd never guess this from the reality-denying nonsense which masquerades as Leftist politics): for the first time in history, for multiple generations the children of the poor would survive to reproductive adulthood at a rate of more than two per woman.
The ground for the industrial revolution was prepared during the middle ages, when average (and peak) intelligence increased in a population which was also creative.
Then, from about 1800 and due to factors including the demographic transition I refer to above, the process went into reverse, and average intelligence (and peak intelligence) began to decline - so the proportion of geniuses began to decline to the current situation when there are very few or none.
Breakthroughs dried-up, the industrial revolution began to unwind, and a return to the agriculture based society began.
So, how many geniuses are needed to make an industrial revolution?
Well, how many did we have compared with now?
If average intelligence has declined by at least a standard deviation in the past century
then what effect could that have?
If we assume that to be in the top 1 percent of the population is the minimum threshold for genius (modern IQ 135) then that level of intelligence would have been found in ten percent of the population in the past - ten-plus times more common.
Among these highly intelligent people, what proportion would have the creative personality (moderately high - but not too high - in Psychoticism/ Schizotypy)? - say very roughly 1 percent,one in a hundred.
So there would have been be about one potential genius per thousand.
From these potential geniuses, how many would realise their potential in relevant fields (because genius is art, literature, music etc is not relevant to the industrial revolution) - plus some would die before maturity, some would be too ill or oppressed to work, some would have sheer bad luck...
Maybe one percent?
So we are now at one genius per 100 thousand population, or 100 geniuses in relevant fields in a country of 10 million - about half that number active at any time (the others being too young or too old).
A point prevalence of 100 geniuses (or somewhat less) to make an industrial revolution?
If intelligence was the whole story, then the growth in population over the past century or two would have been expected to just-about compensate for an approximately tenfold ('order of magnitude) decline in genius - yet genius has apparently all-but disappeared.
So there must be other factors at work.
I do know a couple of people from the British Isles whom I regard as geniuses - the psychiatrist David Healy and the economic historian Greg Clark (from whom I pillaged many of the ideas underlying the above analysis).
But neither are recognised as such, neither are especially 'successful' in career terms. This may be related to the fact that both work on a much broader canvas than is normal - but it also shows that our society does not recognise genius when, rarely, it comes along; or if it does recognise genius, then it is either indifferent or hostile.