As to the scale of humans being “just right”, see J. B. S. Haldane’s 1926 essay, “On Being the Right Size”, of which you can find a full text copy at the Internet Archive.
Haldane concludes his essay on scaling in biology by speculating upon the applicability of the principle to social and political institutions.
And just as there is a best size for every animal, so the same is true for every human institution. In the Greek type of democracy all the citizens could listen to a series of orators and vote directly on questions of legislation. Hence their philosophers held that a small city was the largest possible democratic state. The English invention of representative government made a democratic nation possible, and the possibility was first realized in the United States, and later elsewhere. With the development of broadcasting it has once more become possible for every citizen to listen to the political views of representative orators, and the future may perhaps see the return of the national state to the Greek form of democracy. Even the referendum has been made possible only by the institution of daily newspapers.
To the biologist the problem of socialism appears largely as a problem of size. The extreme socialists desire to run every nation as a single business concern. I do not suppose that Henry Ford would find much difficulty in running Andorra or Luxembourg on a socialistic basis. He has already more men on his pay-roll than their population. It is conceivable that a syndicate of Fords, if we could find them, would make Belgium Ltd or Denmark Inc. pay their way. But while nationalization of certain industries is an obvious possibility in the largest of states, I find it no easier to picture a completely socialized British Empire or United States than an elephant turning somersaults or a hippopotamus jumping a hedge.
This is remarkable coming from a man who later became a supporter of the Communist Party of Great Britain, penning many articles for the Daily Worker, and officially joining the party in 1942. For more on the strange career of J. B. S Haldane, biologist, public intellectual, and Soviet spy, see Gavan Tredoux’s 2018 book, Comrade Haldane Is Too Busy to Go on Holiday.
