A researcher with the science blog Gene Expression has assembled a considerable body of data that indicates a steady, though decidedly modest, interest in adult entertainment over the last 35 years that appears to be declining.
The researcher writes under the handle Agnostic, and he gathered his first body of data from the General Social Survey, collected by the National Opinion Research Center at the University of Chicago. The survey asked men and women if they had watched an X-rated movie in the last year. Data went back to about 1970.
"For men, porn-watching declined at least from 1973 until 1980, and increased until 1987," Agnostic said. "After that, you may be able to see fluctuations up and down but they're around a pretty steady value of about 35 percent.
“The pattern for women is much clearer to see,” he added, “essentially no trend, but cycles of varying period and amplitude."
Agnostic noted that the arrival of Internet did not spark a boom in adult movie-watching. To see the full graph, click here.
Circulation figures for Playboy Magazine and a selection of racy "lad" magazines like Maxim, Stuff, FHM and Loaded composed the next body of data. Except for the U.S. edition of Maxim, all of these magazines have seen their circulation figures drop in recent years. All of the British lad magazines have seen their circulations fall dramatically.
Agnostic conceded that these magazines aren't exactly porn, citing anecdotal evidence from his research indicating that circulation rates for other adult magazines have fallen. Arguably, declines in circulation of adult magazines may reflect declining subscription rates for magazines overall or the effect of online media on hard copy publications.
In a related argument, Agnostic addressed the theory that the current generation is more promiscuous than previous generations. Contradictory to this idea, he pointed to data from the National Youth Risk Behavior Survey indicating that the percentage of high-school age students who have had four or more sexual partners decreased between the years of 1991 and 2007.
In a related study, earlier this year Northwestern University Law Professor Anthony D'Amato argued that the proliferation of Internet porn went hand-in-hand with a steady decrease in attempted and completed rapes, citing numbers from the U.S. Department of Justice Bureau of Justice Statistics.