Sonny Liston was illiterate ....but he was witty ...with a good sense of humor. ...he might not have had the opportunities that some of these kids today have
Many to choose from, but these come to mind right away - Jack Johnson - a self-made man in many ways, learned his lessons well from the school of hard knocks. Became a true craftsman as a fighter, and was fluent in three languages. Owned restaurants and played the bass viola while training for Jeffries. Was equally at home with the poor and royalty. His love of the good life was greater than his business acumen and he couldn't hold on to his fortunes. Gene Tunney - a well-read man. Had a reputation as a Shakespeare scholar. As a fighter, always thoroughly studied his opposition while planning strategy. His reading of Jack London's "The Game" influenced his decision to retire from boxing before 'the game' defeated him. After boxing was on the board of directors of several major corporations. Max Schmeling - lost everything in WW2 - his home, his fortunes, his boxing trophies. Started from scratch after the war and became CEO of Coca Cola in Germany. Jack Dempsey - after losing millions in the 1929 stock market crash, became a successful boxing promoter and the owner of a very successful Broadway restaurant which he ran until near the end of his life. Larry Holmes - invested wisely and held onto his money. He owned several successful businesses in his hometown, Easton, PA.
Who knows ? It's impossible to tell how intelligent someone is unless you know them really well, and you'd have to be intelligent yourself enough to be able to gauge theirs. But, of course, it's not that difficult to detect bad levels of stupidity, so I guess you could rule some out. I don't know why people rate Gene Tunney. He was literate and managed to marry an heiress, but a lot of what he said or wrote was really stupid, and theirs are lot of stupidity in the upper classes too. He was also a pompous racist, and just comes across as someone of low, limited or average intelligence at best, who's arrogant and unaware enough to posture as being cleverer than what he is and believe his own BS. Being literate doesn't mean intelligent, it just means someone taught you to read. He did make a lot of money and retired early though, so I'll give him credit for a smart move or two.
Yea Larry Holmes comes to mind. In and also out of the ring. I believe Ken Norton was highly intelligent.
Honestly, I find it really relaxing, I play one minute plus one second and say I play a dozen I come out the other side with my mind just wiped clean of whatever. Really works for me.
A few that strike me as being smarter than average that no one has mentioned are Max Baer, Mike Tyson and Tyson Fury.
You go way to far in your condemnation of Tunney, just like the rubes of his own time who thought he was too snooty with all this "readin' and stuff" and who didn't like his "fightin' style"..
Larry Holmes is overlooked both in and out the ring because of his controversial statements but he was both very smart when fighting and invested his money well into several businesses and his own gym. The guy could also make smart observations and witty remarks. Wladmir outside the ring is obviously very book smart and and educated and he is no dummy or slow witted either. A reporter told him James Toney was talking trash and he immediately responded "let him keep talking". Ali was clearly highly sharp in the way he could mentally spar with people or holds his own in debated despite his lack of education. Was way too trusting and kind hearted tho and this lead to him losing lots of money. Tyson if you listen to him speak had very high emotional IQ and had lots of down to Earth common sense. Smart in the ring too. Foreman's in the ring IQ was like -100 in the 70's and then did a complete reversal in his comeback. As a businessman he is probably #1 or #2 after Gene Tunney.