Here for example is a letter from John Quincy Adams to his father, written when he was ten:

>DEAR SIR,—I love to receive letters very well; much better than I love to write them. I make but a poor figure at composition, my head is too fickle, my thoughts are running after birds eggs play and trifles, till I get vexed with myself. Mamma has a troublesome task to keep me steady, and I own I am ashamed of myself. [...] If I can but keep my resolution, I will write again at the end of the week and give a better account of myself. I wish, Sir, you would give me some instructions, with regard to my time, and advise me how to proportion my Studies and my Play, in writing, and I will keep them by me, and endeavor to follow them. I am, dear Sir, with a present determination of growing better, yours.

>P. S.—Sir, if you will be so good as to favor me with a Blank Book, I will transcribe the most remarkable occurances I meet with in my reading, which will serve to fix them upon my mind.

An art that I appreciate more is at the opposite end. Constructing elegant prose out of relatively simple sentences, like Ernest Hemingway.

"He was an old man who fished alone in a skiff in the Gulf Stream and he had gone eighty-four days now without taking a fish. In the first forty days a boy had been with him. But after forty days without a fish the boy's parents had told him that the old man was now definitely and finally salao, which is the worst form of unlucky, and the boy had gone at their orders in another boat which caught three good fish the first week. It made the boy sad to see the old man come in each day with his skiff empty and he always went down to help him carry either the coiled lines or the gaff and harpoon and the sail that was furled around the mast. The sail was patched with flour sacks and, furled, it looked like the flag of permanent defeat."

Long sentences for sure, but is there any nesting in there at all? I can't see any.

Agglutination in many Native American languages and compounding in many Indo-European languages come to mind as examples where interesting nesting and complex relational structures can be found at the level of the word.

The article suggests that speakers of English or German can do "mental arithmetic" whereas speakers of Ket have lots of "math facts." I don't know anything about Ket, but German, Sanskrit, and other languages seem to have a lot in the way of mental arithmetic when it comes to making up long compound words, which are not such a static or stable currency as in, say, English.

I wonder if the missing brackets are an artifact of some weird automated typesetting/rendering or if an editor who never bothered to read the article came through and said, "Quotations shouldn't start and end with random brackets!"