Research Suggests the Grubbs, Perry, Wilt, Reid Review Is Disingenuous (“Pornography Problems Due to Moral Incongruence: An Integrative Model with a Systematic Review and Meta-Analysis”)

The authors of this review would have readers believe that self-identification as a porn addict is a function of religious shame/moral disapproval about porn. They only reviewed a small number of studies, which rely on the CPUI-9, an instrument developed by co-author Grubbs that produces skewed findings. The co-authors carefully omitted or misrepresented opposing research that has convincingly demonstrated that the studies they relied on in their review are misleading.

It is not “religiousness” or “moral disapproval” that predicts self-perception as a porn addict, as they imply, but rather porn use levels. Let’s look at the opposing evidence more closely.

Porn use levels are by far the strongest predictor of self-perceived porn addiction

The first study is the only study that directly correlated self-identification as a porn addict with hours of use, religiousness and moral disapproval of porn use. Its findings contradict the carefully constructed narrative about “perceived addiction” (that “porn addiction is just religious shame/moral disapproval”) – which is grounded in studies employing the flawed instrument called the CPUI-9. In this study, the strongest correlation with self-perception as an addict was with hours of porn use. Religiousness was irrelevant, and while there was predictably some correlation between self-perception as an addict and moral incongruence regarding porn use, it was roughly half the hours-of-use correlation.

In short, the porn users who thought they were addicted really were using more porn, just as one would expect of compulsive (or addicted) porn users.

To understand how this research undermines all of the CPUI-9 studies, more background is helpful. (A detailed discussion of the CPUI-9 appears at the bottom of this page.) The key insight is that the CPUI-9 includes 3 “guilt and shame/emotional distress” questions not normally found in addiction instrumentswhich skew its results, causing religious porn users to score higher and non-religious users to score lower than subjects do on standard addiction-assessment instruments. By itself this flawed instrument might have done little harm, but its creator then conflated the term “perceived addiction” with the total score on the CPUI-9. Thus, a new, very misleading meme was born, and it was immediately snapped up by anti-porn addiction advocates and plastered all over the media.

The term “perceived pornography addiction” is misleading in the extreme, because it’s just a meaningless score on an instrument that produces skewed results. But people assumed they understood what “perceived addiction” meant. They presumed it meant that the CPUI-9’s creator, Dr. Grubbs, had figured out a way to distinguish actual “addiction” from “belief in addiction.” He hadn’t. He had just given a deceptive label to his “porn use inventory,” the CPUI-9 (its 9 questions are reproduced at the bottom of the page). However, Dr. Grubbs made no effort to correct the misperceptions that rolled out into the media, pushed by anti-porn addiction sexologists and their media chums.

Misled journalists mistakenly summed up CPUI-9 findings as:

  • Believing in porn addiction is the source of your problems, not porn use itself.
  • Religious porn users are not really addicted to porn (even if they score high on the Grubbs CPUI-9) – they just have shame.

Even some sincere clinicians were duped, because some clients really do believe their porn use is more destructive and pathological than their therapists think it is. These therapists assumed the Grubbs test somehow isolated these mistaken clients when it didn’t, and they adopted (and repeated) the new meme uncritically.

As the saying goes, “The only cure for bad science is more science.” Faced with thoughtful skepticism about his assumptions, and the media’s unfounded claims that his CPUI-9 instrument could indeed distinguish “perceived pornography addiction” from genuine problematic porn use, Dr. Grubbs finally did the right thing as a scientist. He pre-registered a study to test his hypotheses/assumptions directly (not using the CPUI-9). Pre-registration is a sound scientific practice that prevents researchers from changing hypotheses after collecting data.

The results of Grubbs’s pre-registered study contradicted both his earlier conclusions and the meme (“porn addiction is just shame”) that the press helped to popularize.

Details: Dr. Grubbs set out to prove that religiosity was indeed the main predictor of “believing yourself addicted to porn.” He and his team of researchers surveyed 3 good-sized, diverse samples (male, female, etc.). He posted the results online, although his team’s paper has not yet been formally published.

As stated, this time he didn’t rely on his CPUI-9 instrument. Instead, the Grubbs team asked 2 direct ‘yes/no’ questions of porn users (“I believe that I am addicted to internet pornography.” “I would call myself an internet pornography addict.”), and compared results with variables such as hours of use, religiousness and scores on a “moral disapproval of porn” questionnaire.

Directly contradicting his earlier claims, Dr. Grubbs and his research team found that believing you are addicted to porn correlates most strongly with daily hours of porn use, not with religiousness. As noted below, some of Dr. Grubbs’s earlier studies also found that hours of use was a stronger predictor of “perceived addiction” (total CPUI-9 score) than religiosity – findings that continually did not make it into the mainstream media (or Dr. Grubbs’s own summaries).

From the new study’s abstract:

In contrast to prior literature indicating that moral incongruence and religiousness are the best predictors of perceived addiction [CPUI-9 total score], results from all three samples indicated that male gender and pornography use behaviors were the most strongly associated with self-identification as a pornography addict.

Being male is also strongly predictive of self-labeling as “addicted.” According to Dr. Grubbs, rates of male porn users who answered “yes” to one of the “addicted” questions ranged from 8-20% in the new study’s samples. These rates are consistent with other 2017 research (19% of college males addicted).

In short, there is widespread distress among some of today’s porn users. High rates of problematic use suggest that the World Health Organization’s proposed diagnosis of “Compulsive sexual behavior disorder” is genuinely needed to insure that problematic porn use is properly studied and those suffering are properly treated.

Based on their results in the new pre-registered study, Dr. Grubbs and his co-authors concluded that, “mental and sexual health professionals should take the concerns of clients identifying as pornography addicts seriously.” (emphasis supplied)

Astonishingly, Grubbs, Perry, Wilt and Reid “review” portrays the CPUI-9-based narrative as alive and well. They ignore the research described above, which totally contradicts their conclusions. The “review” also inadequately describes the significance of Fernandez, Tee & Fernandez, a study that also powerfully undermines the narrative these authors present, as explained in the next section.

A peer-reviewed non-Grubbs study also questioned the CPUI-9’s ability to assess either perceived or actual porn addiction

The above study is not the only ones to cast doubt on Dr. Grubbs’s conclusions and the press about them. In September, 2017, another study came out, which tested one of Dr. Grubbs’s hypotheses: Do Cyber Pornography Use Inventory-9 Scores Reflect Actual Compulsivity in Internet Pornography Use? Exploring the Role of Abstinence Effort.

The researchers measured actual compulsivity by asking participants to abstain from internet porn for 14 days. (Only a handful of studies have asked participants to abstain from porn use, which is one of the most unambiguous ways to reveal its effects.)

Study participants took the CPUI-9 before and after their 14-day attempt at porn abstinence. (Note: They did not abstain from masturbation or sex, only internet porn.) The researchers’ main objective was to compare ‘before’ and ‘after’ scores of the 3 sections of the CPUI-9 to several variables.

Among other findings (discussed in depth here), the inability to control use (failed abstinence attempts) correlated with the CPUI-9’s actual addiction questions 1-6, but not with the CPUI-9’s guilt and shame (emotional distress) questions 7-9. Similarly, “moral disapproval” of pornography use was only slightly related to CPUI-9 “Perceived Compulsivity” scores. These results suggest that the CPUI-9 guilt and shame questions (7-9) shouldn’t be part of a porn addiction (or even “perceived porn addiction”) assessment because they are unrelated to frequency of porn use.

To say it differently, the most addicted subjects did not score higher on religiosity. Moreover, no matter how it is measured, actual porn addiction/compulsivity is strongly correlated with higher levels of porn use, rather than with “emotional distress” questions (guilt and shame).

In summary Dr. Grubbs’s own pre-registered study and the Fernandez studies support the following:

  1. Religiousness does not “cause” porn addiction. Religiosity is not related to believing you are addicted to porn.
  2. The amount of porn viewed is the strongest predictor (by far) of actual porn addiction or belief that someone is addicted to porn.
  3. The “perceived addiction” studies (or any study that uses the CPUI-9) does not, in fact, assess “perceived porn addiction” or “belief in porn addiction” or “self-labeling as an addict,” let alone distinguish “perceived” from actual addiction.

Background about the CPUI-9 – and how it always produces badly skewed results

In the last few years Dr. Joshua Grubbs has authored a series of studies correlating porn users’ religiosity, hours of porn use, moral disapproval, and other variables with scores on his 9-item questionnaire “The Cyber Pornography Use Inventory” (CPUI-9). In an odd decision that has lead to much misunderstanding of his findings, Dr. Grubbs refers to his subjects’ total CPUI-9 score as “perceived pornography addiction.” This gives the false impression that his CPUI-9 instrument somehow indicates the degree to which a subject merely “perceives” he is addicted (rather than being actually addicted). But no instrument can do that, and certainly not this one.

To say it another way, the phrase “perceived pornography addiction” indicates nothing more than a number: the total score on the following 9-item pornography-use questionnaire with its three extraneous questions about guilt and shame. It doesn’t sort the wheat from the chaff in terms of perceived vs. genuine addiction. Nor does the CPUI-9 assess actual porn addiction.

Perceived Compulsivity Section

  1. I believe I am addicted to Internet pornography.
  2. I feel unable to stop my use of online pornography.
  3. Even when I do not want to view pornography online, I feel drawn to it

Access Efforts Section

  1. At times, I try to arrange my schedule so that I will be able to be alone in order to view pornography.
  2. I have refused to go out with friends or attend certain social functions to have the opportunity to view pornography.
  3. I have put off important priorities to view pornography.

Emotional Distress Section

  1. I feel ashamed after viewing pornography online.
  2. I feel depressed after viewing pornography online.
  3. I feel sick after viewing pornography online.

As you can see, the CPUI-9 cannot distinguish between actual porn addiction and “belief” in porn addiction. Subjects never “labeled themselves as porn addicts” in any Grubbs study. They simply answered the 9 questions above, and earned a total score.

What correlations did the Grubbs studies actually report? Total CPUI-9 scores were related to religiosity (as explained above), but also related to “hours of porn viewed per week.” In some Grubbs studies a slightly stronger correlation occurred between religiosity and total CPUI-9 scores (“perceived porn addiction”) in others a stronger correlation occurred with hours of porn use and total CPUI-9 scores (“perceived porn addiction”).

The media ignored the latter findings and grabbed onto the correlation between religiosity and total CPUI-9 scores (now misleadingly labeled “perceived addiction”), and in the process journalists morphed the finding into “religious people only believe they’re addicted to porn.” The media ignored the just-as-strong correlation between CPUI-9 scores and hours of porn use, and pumped out hundreds of inaccurate articles like this blog post by David Ley: Your Belief in Porn Addiction Makes Things Worse: The label of “porn addict” causes depression but porn watching doesn’t. Here is Ley’s inaccurate description of a Grubbs CPUI-9 study:

If someone believed they were a sex addict, this belief predicted downstream psychological suffering, no matter how much, or how little, porn they were actually using.

Removing Ley’s misrepresentations, the above sentence would accurately read: “Higher scores on the CPUI-9 correlated with scores on a psychological distress questionnaire (anxiety, depression, anger).” Which is how it tends to be for any addiction questionnaire. For example, higher scores on an alcohol use questionnaire correlate with higher levels of psychological distress. Big surprise.

The key to all the dubious claims and questionable correlations: the Emotional Distress questions (7-9) cause religious porn users to score much higher and secular porn users to score far lower, as well as creating a strong correlation between “moral disapproval” and total CPUI-9 score (“perceived porn addiction”).

To put it another way, if you use only results from CPUI-9 questions 1-6 (which assess the signs and symptoms of an actual addiction), the correlations dramatically change – and all the dubious articles claiming shame is the “real” cause porn addiction would never have been written.

To look at a few revealing correlations, let’s use data from the 2015 Grubbs paper (“Transgression as Addiction: Religiosity and Moral Disapproval as Predictors of Perceived Addiction to Pornography“). It comprises 3 separate studies and its provocative title suggests that religiosity and moral disapproval “cause” a belief in pornography addiction.

Tips for understanding the numbers in the table: zero means no correlation between two variables; 1.00 means a complete correlation between two variables. The bigger the number the stronger the correlation between the 2 variables.

In this first correlation we see how moral disapproval correlates powerfully with the 3 guilt and shame questions (Emotional Distress), yet weakly with the two other sections that assess actual addiction (questions 1-6). The Emotional Distress questions cause moral disapproval to be the strongest predictor of total CPUI-9 scores (“perceived addiction”).

But if we use only the actual porn addiction questions (1-6), the correlation is pretty weak with Moral Disapproval (in science-speak, Moral Disapproval is a weak predictor of porn addiction).

The second half of the story is how the same 3 Emotional Distress correlate very poorly with levels of porn use, while the actual porn addiction questions (1-6) correlate robustly with porn use levels.

This is how the 3 Emotional Distress questions skew results. They lead to reduced correlations between “hours of porn use” and total CPUI-9 scores (“perceived addiction”). Next, the sum total of all 3 sections of the CPUI-9 test is deceptively re-labeled as “perceived addiction” by Grubbs. Then, at the hands of determined anti-porn-addiction activists, “perceived addiction” morphs into “self identifying as a porn addict.” The activists have pounced on the strong correlation with moral disapproval, which the CPUI-9 always produces, and presto! they now claim that, “a belief in porn addiction is nothing more than shame!”

It’s a house of cards built on 3 guilt and shame question not found in any other addiction assessment, in combination with the misleading term the questionnaire’s creator uses to label his 9 questions (as a measure of “perceived porn addiction”).

The CPUI-9 house of cards came tumbling down with a 2017 study that pretty much invalidates the CPUI-9 as an instrument to assess either “perceived pornography addiction” or actual pornography addiction: Do Cyber Pornography Use Inventory-9 Scores Reflect Actual Compulsivity in Internet Pornography Use? Exploring the Role of Abstinence Effort. It also found that 1/3 of the CPUI-9 questions should be omitted to return valid results related to “moral disapproval,” “religiosity,” and “hours of porn use.” You see all the key excerpts here, but Fernandez et al., 2018 sums things up:

Second, our findings cast doubts on the suitability of the inclusion of the Emotional Distress subscale as part of the CPUI-9. As consistently found across multiple studies (e.g., Grubbs et al., 2015a,c), our findings also showed that frequency of IP use had no relationship with Emotional Distress scores. More importantly, actual compulsivity as conceptualized in the present study (failed abstinence attempts x abstinence effort) had no relationship with Emotional Distress scores.

Emotional Distress scores were significantly predicted by moral disapproval, in line with previous studies which also found a substantial overlap between the two (Grubbs et al., 2015a; Wilt et al., 2016)…. As such, the inclusion of the Emotional Distress subscale as part of the CPUI-9 might skew results in such a way that it inflates the total perceived addiction scores of IP users who morally disapprove of pornography, and deflates the total perceived addiction scores of IP users who have high Perceived Compulsivity scores, but low moral disapproval of pornography.

This may be because the Emotional Distress subscale was based on an original “Guilt” scale which was developed for use particularly with religious populations (Grubbs et al., 2010), and its utility with non-religious populations remains uncertain in light of subsequent findings related to this scale.

Here’s is the core finding: The 3 “Emotional Distress” questions have no place in the CPUI-9, or any porn addiction questionnaire. These guilt and shame questions do not assess distress surrounding addictive porn use or “perception of addiction.” These 3 questions merely artificially inflate total CPUI-9 scores for religious individuals while deflating total CPUI-9 scores for nonreligious porn addicts.

In summary, the conclusions and claims spawned by the CPUI-9 are simply invalid. Joshua Grubbs created a questionnaire that cannot, and was never validated for, sorting “perceived” from actual addiction: the CPUI-9. With zero scientific justification he re-labeled his CPUI-9 as a “perceived pornography addiction” questionnaire.

Because the CPUI-9 included 3 extraneous questions assessing guilt and shame, religious porn users’ CPUI-9 scores tend to be skewed upward. The existence of higher CPUI-9 scores for religious porn users was then fed to the media as a claim that, “religious people falsely believe they are addicted to porn.” This was followed by several studies correlating moral disapproval with CPUI-9 scores. Since religious people as a group score higher on moral disapproval, and (thus) the total CPUI-9, it was pronounced (without actual support) that religious-based moral disapproval is the true cause of pornography addiction. That’s quite a leap, and unjustified as a matter of science.

YouTube presentation exposing the CPUI-9 and the myth of “perceived addiction”: Pornography Addiction and Perceived Addiction 

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