Prof Flynn was awarded an honorary doctor of science degree by the university at a capping ceremony at the Dunedin Town Hall on Saturday and gave the graduation address.
About 500 graduands in science, applied science, consumer and applied sciences, physical education and surveying graduated in person at the ceremony.
Prof Flynn, a moral philosopher who is deeply involved in the disciplines of politics and psychology, said he had enjoyed his teaching, and was still lecturing many years past retirement age.
His "one disappointment" was that during 50 years at universities in America and New Zealand, he had noticed a trend for fewer and fewer students reading great works of literature.
Through his politics teaching, he had been fighting a rearguard action by assigning students works that shed light on human psychology, history or philosophy.
Last year, he had studied trends in American vocabulary used in everyday life.
In 1948, teenagers could both understand and use the vocabularies of their parents.
In 2006, they could understand their parents, but, to a surprising degree, could not initiate a conversation using adult language.
"The damage is not permanent. They make up some of the gap if they go to university, and a few years after they have entered the world of work, they make up the rest."
Prof Flynn noted the relatively recent emergence of a "teenage subculture" which had developed its own English dialect and had become so insulated that its members were not socialised into their society's "speech community".
This new subculture was "strongly visual, with leisure time spent on the web and watching TV and films", and it was also an "audio culture, with a constant surround of popular music".
"I suspect that it has little time left to place high priority on reading literature that requires concentration and wide general knowledge.
"You are unlikely to enjoy Tolstoy's War and Peace if the vocabulary is unfamiliar and you do not know who Napoleon was or where Russia is.
"I suggest that teenage culture not only gives university students a vocabulary gap, but also creates a love-of-reading deficit."
He recalled that he had since set a question about tyranny in the 20th century and only a few students could volunteer Hitler's name.
"Let me convince you how pleasurable it will be for you to learn through literature. Both you and your civilisation will be better off."
He urged students to read great works of literature, including novels such as Erich Maria Remarque's All Quiet on the Western Front.
Otago University vice-chancellor Prof Sir David Skegg said Prof Flynn's scholarship in areas including intelligence research, the race and IQ debate, and the defence of humane ideals, had earned him renown.
His discovery and clarification of the large gains in IQ over time in many countries has become known internationally as the Flynn Effect.
In 2007, he was named Distinguished Scientist of the Year by the International Society for Intelligence Research.
