""After examining the sexual practices of more than 80 primitive and more advanced societies, [Professor J. D.] Unwin concluded that sexually permissive behavior led to less cultural energy, less creativity, less individualism, less mental development and less cultural progress in general. Primitive societies with the greatest sexual freedom had made the least cultural advances. Those with stricter limitations had made the greatest progress. Among civilized societies, the same rule held. Those with restrictive sexual codes had made the greatest cultural strides, and when more permissive sexual standards appeared, cultural decline set in. Unwin said there was no known instance of a society that retained as high a cultural level after relatively relaxed sexual standards replaced more rigorous ones (although he conceded that it might take several generations before the debilitating effect was clearly manifest).
"William Stephens, after studying 90 primitive cultures, wrote that the tribes lowest on the scale of cultural evolution have the most sexual freedom. Sigmund Freud, surprisingly to some, associated cultural advances with limitations on sexual activity. Arnold Toynbee, celebrated student of world civilizations, declared that a culture which postpones rather than stimulates sexual experience in the young is a culture most prone to progress. Will and Ariel Durant, after a lifetime of studying world history, wrote in The Lessons of History that it was imperative to maintain rigorous sexual restraint upon the young..."
--Exerpts are from an address delivered in the mid-1980s by Reo M. Christenson - Professor of Political Science, Miami University, Oxford, OH