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More on Porn: Guard Your Manhood—A Response to Marty Klein

Marty Klein wrote a reaction to our original post on how porn is shaping young men’s sexual response. Klein suggested that science doesn’t empirically support our assertion of unprecedented rates of sexual dysfunctions in young men. In fact, all studies assessing young male sexuality since 2010 report historic levels of sexual dysfunctions and startling rates of low libido. Erectile dysfunction (ED) rates range from 27 to 33 percent, while rates for low libido (hypo-sexuality) range from 16 to 37 percent. The lower ranges are taken from studies involving teens and men 25 years old and under, while the higher ranges are from studies involving men 40 years old and under.

Prior to the advent of free streaming online porn, cross-sectional studies and meta-analyses consistently reported ED rates of 2 to 3 percent in men under 40. That’s about a 1000 percent increase in youthful ED rates in the last 20 years. Klein dismisses this rising tsunami of empirically documented sexual dysfunction in young men as normal teenage performance anxiety, which raises the question: if not high speed Internet porn, what variable changed that could account for this astronomical rise?

Incidentally, if you cannot achieve an erection without using online porn or fantasizing about porn you have watched (but can get an erection and climax with porn), you should consider the possibility you may be part of this unfortunate swell.

Before we address the scant “null results” research Klein cites to exonerate online porn, you should know that he hasn’t told you about a growing list of studies that do find associations between solo porn use and arousal, attraction, and sexual performance problems. Findings include difficulty orgasming, diminished libido or erectile function (1, 2, 3, 4, 5, 6), negative effects on partnered sex, decreased enjoyment of sexual intimacy (1, 2, 3), less sexual and relationship satisfaction (1, 2, 3, 4), a preference for using Internet pornography to achieve and maintain arousal over having sex with a partner, and greater brain activation in response to pornography in those reporting less desire for sex with partners. Online porn use even correlates with abnormally … low sexual desire in high school seniors.

The most interesting of these items is a 2007 chapter by Kinsey Institute researchers who were among the first to report porn-induced ED and low libido. Half of subjects were recruited from bars and bathhouses where porn was “omnipresent” and continuously playing. These subjects had difficulty achieving erections in the lab in response to video porn. In talking with the subjects, the researchers discovered that high exposure to porn videos apparently resulted in lower responsivity and an increased need for novelty and “kink.” Two recent brain studies found that more porn use correlated with less brain activation to sexual images (1, 2). A third brain study found that porn addicts’ brains habituated faster to sexual images.

Ignoring all of the above evidence, Klein cites only heavily criticized research by Prause and Pfaus, and inconclusive research by Landripet & Stülhofer. Let’s take a closer look at their papers.

The Prause and Pfaus paper wasn’t a study at all, and no actual erections were assessed in its making. Prause claims to have gathered data from four of her earlier studies, none of which addressed ED. However, the data in Prause and Pfaus doesn’t match the data in the earlier studies. The discrepancies are not small and remain unexplained. A comment by researcher Richard A. Isenberg MD highlights some (but not all) of the flaws, which also include unsupported claims, poor methodology and conclusions in opposition with data.

Landripet and Stülhofer surveyed men in Norway, Croatia and Portugal. In addition to drawing formal criticism from Danish pornography expert Gert Martin Hald, this paper actually found correlations between ED and porn use. For example, the abstract doesn’t mention a rather important correlation. Only 40 percent of the Portuguese men used porn “frequently,” while the 60 percent of the Norwegians used porn “frequently.” The Portuguese men had far less sexual dysfunction than the Norwegians. Elsewhere in the paper, Landripet & Stülhofer acknowledge a statistically significant association between more frequent porn use and ED, but claim the effect size was small. Hald pointed out that, “In pornography research — even small effect sizes may carry considerable social and practical significance.”

What else did the authors overlook to generate their “null results” claims? For example, what variables should have been considered if their objective was to investigate porn’s role in sexual dysfunctions? Hald emphasized the need to assess more variables (mediators, moderators) than just frequency per week in the last year.

Truth is, researchers can’t “disprove” porn’s potential role in soaring sexual dysfunctions in men under 40 by comparing only a single variable such as “frequency of use in the last year” with only ED (rather than with the full range of sexual performance problems today’s porn users typically report). They need to investigate a combination of variables. For example: ratio of masturbation to porn versus masturbation without porn, ratio of sexual activity with a person versus masturbation to porn, gaps in partnered sex (where one relies only on porn), virgin or not, years of use, age regular Internet porn use started, escalation to new genres, novelty per session (i.e. compilation videos, multiple tabs), and presence of hypersexuality/porn addiction.

As we explained in our original post, there’s only one practical way to confirm whether erectile dysfunction, delayed ejaculation or abnormally low desire for sex with a partner is porn-induced or not: eliminate porn use for an extended period and see if normal sexual response returns.

So far, only one published study had a subject with suspected porn-induced sexual problems abstain from porn. Guess what? In eight months the man had recovered from anorgasmia, low libido and porn-related fetishes, and was enjoying satisfying sexual relations with his girlfriend. That’s one-for-one on studies truly assessing porn-induced sexual problems. In addition, this page contains articles and videos by about 60 experts (urology professors, urologists, psychiatrists, psychologists, sexologists, MDs) who acknowledge and have successfully treated porn-induced ED or porn-induced loss of sexual desire. My (Gary’s) website,, has documented the experiences of a few thousand men who removed online porn from their lives and recovered from chronic sexual dysfunctions.

Klein would have us believe that any perceived rise in erectile problems is due to widespread requests for sexual enhancement drugs. However, the ED-rate studies summarized above do not rely on percentages of men requesting medications from their doctors. They rely on peer-reviewed studies (usually anonymous) of population-wide sexual dysfunction rates.

For the “Viagra hypothesis” to be true, it would have to be the case that young male participants consistently lied about their erectile functioning in every study published between 1948 and 2010, worldwide. Then, suddenly, in 2010 all the young men (and only the young men) began to tell the truth about their ED problems. This is highly unlikely.

Klein implies the evidence we presented of online porn’s effects on users is scarce and isolated, with “tiny sample sizes.” In our article we cited twenty-four recent neuroscience studies on porn users, along with five recent reviews of the literature. The complete up-to-date list is here. Every study listed suggests that overuse of online porn has measurable adverse effects on some brains. Some of these effects could help explain rising sexual dysfunctions. All competent scientists add caveats to their studies. However, the authors of every paper listed at the above link state that their findings mirror the findings seen in drug addiction studies. This is not disputable. We merely reported their conclusions.

All addiction is one condition, and “sexual behavior addiction” not only exists but involves the same fundamental mechanisms and brain changes as substance addiction.

fMRI studies tend to be far smaller than online surveys due to their high cost, but Klein’s claim that some studies had 10–15 subjects is false. The lowest number of subjects was 19 (plus matched controls), while the highest was 67. Moreover, these neuroscience findings align with more than 140 recent brain studies on internet addicts. And all of those studies are consistent with decades of addiction neuroscience research on both substance and behavioral addiction, a reality codified in the American Society of Addiction Medicine’s new definition of addiction. All addiction is one condition, and “sexual behavior addiction“ not only exists but involves the same fundamental mechanisms and brain changes as substance addiction.

Klein supports his argument almost entirely with a 2012 article. By inviting his readers to travel back in time, Klein avoids addressing the flood of recent studies on online porn users’ brains described above. The studies have found the precise brain changes that’s experts, Rory Reid, Bruce Carpenter and Barry Komisaruk, said don’t exist.

Klein tries to assure readers that the brain activation in porn users is no different from the brain activation for viewing sunsets or watching the NBA play-offs. This familiar talking point endeavors to paint the false picture that all brain changes are equal. In reality, brain changes caused by addiction are specific and have profound negative consequences. These include hyper-reactivity to porn related cues, a numbed pleasure response to everyday rewards (often leading to desire for more extreme stimulation), reduced impulse control and ability to foresee consequences, and a dysfunctional stress response.

There are multiple biological reasons we experience other pleasures differently from a mind-blowing orgasm. Sexual stimulation releases higher amounts of dopamine and opioids than any other natural reward. Also, sexual stimulation and addictive drugs activate the exact same reward system nerve cells, which are distinct from those for other natural rewards. This helps explain why prolonged edging to porn and using cocaine can both be so compelling, and why other non-drug rewards are less so. Not too many “sunset addiction” recovery forums on the web.

Klein takes us to task for not ascribing these young men’s difficulties to masturbation rather than online porn use. Is Klein seriously suggesting that masturbation leads to chronic sexual dysfunctions that require months to heal (as reported by many of today’s young porn users)? Where’s the data for that far-fetched assertion? Second, does he realize that today’s porn users often watch porn when they’re not masturbating? Think libraries, during class, buses, Starbucks.

Klein concludes by telling us not to “imagine that without porn, young men will go back to some mythical pre-Internet time when their ideas about sex were realistic, their erections were always firm, and their desire always high.” Yet that is exactly what is happening in men who quit using online porn. Former porn users report sexual dysfunction reversal and real partners looking “hot” again. In short, young men once again perform with the prowess of any healthy mammal.

In the end, you have nothing to lose by experimenting for yourself and laying off porn for a while. Don’t let sexology hype encourage you to give up on healthy sexual responsiveness. END

About the authors

Philip Zimbardo is internationally recognized as the “voice and face of contemporary psychology” through his widely viewed PBS-TV series, Discovering Psychology, and his classic research, The Stanford Prison Experiment. Noted for his personal and professional efforts to actually “give psychology away to the public,” Zimbardo has also been a social-political activist, challenging the Government’s wars in Vietnam and Iraq, as well as the American Correctional System. Zimbardo has been President of the American Psychological Association (2002), President of the Western Psychological Association (twice), Chair of the Council of Scientific Society Presidents (CSSP), and now Chair of the Western Psychological Foundation.

Gary Wilson is the author of Your Brain on Porn: Internet Pornography and the Emerging Science of Addiction, presenter of the popular TEDx talk “The Great Porn Experiment” and host of the website “Your Brain On Porn,” which was created for those seeking to understand and reverse compulsive porn. He taught anatomy and physiology for years and has long been interested in the neurochemistry of addiction, mating and bonding.

Nikita Coulombe is a writer and artist who co-authored Man Interrupted with social psychologist Philip Zimbardo. She also assisted Warren Farrell with his upcoming book, The Boy Crisis. Passionate about understanding human nature, she co-founded the sex ed blog,

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