Abstract

The causal relationships between pornography use, masturbation, moral incongruence, and mental health are poorly understood. While the link between problematic pornography use (PPU) and depression is well documented, the temporal dynamics associated with pornography use and masturbation have not yet been quantified. Utilizing an exploratory ecological momentary assessment (EMA) design, we measured the temporal dynamics of cognitive and affective state variables collected from 22 participants before, during, and after pornography use and masturbation, and examined the moderating role of moral incongruence in these relationships. Participants completed an initial survey followed by a four-week EMA, capturing data on sexual activities and cognitive and affective state variables. Bayesian hierarchical mixed-effects models were employed to analyze temporal dynamics. Findings suggest that pornography use and masturbation were linked to changes in affective and cognitive states that spiked both before and after sexual episodes. These states were generally more pronounced and sustained in participants with high moral incongruence, who experienced transient increases in shame, guilt, difficulty thinking, relationship disconnectedness, craving for sexual intercourse, and mood deterioration after pornography use and masturbation. These shifts typically persisted for several hours before decaying to baseline levels. High-incongruence participants also experienced strong spikes in craving prior to sexual episodes, while low-incongruence participants experienced craving spikes after pornography use and masturbation, indicating possible sensitization effects. Our findings also signalled potential evidence for “brain fog” following pornography use in both low and high-incongruence participants. Further, we discovered opponent process dynamics in the mood of high-incongruence participants, providing a possible causal mechanism that may explain how PPU can lead to depression.

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Introduction

Problematic Pornography Use

Problematic pornography use (PPU) is characterized by a pattern of pornography consumption that causes distress and functional impairment across personal, social, or occupational areas, and is marked by an inability to control pornography use despite these adverse effects (Bőthe et al., 2024a, 2024b; Ince et al., 2021).Footnote 1 The International Sex Survey has estimated that between 3.2 and 16.6% of the populations from 42 countries are predicted to have PPU (Bőthe et al., 2024a, 2024b), which has only recently been clinically recognized as an impulse control disorder, having been added as a subcategory of Compulsive Sexual Behavior Disorder in the 11th edition of the International Classification of Diseases (Kraus et al., 2018).

Yet despite this recognition, there remains controversy over whether PPU should be classified as an addiction or an impulse control disorder (Bőthe et al., 2024a, 2024b; Brand et al., 2020; Pistre et al., 2023). While compulsive pornography use can have negative psychosocial consequences, PPU has features overlapping both behavioral addictions and impulse control disorders, and as such may have a distinct aetiology from true addiction (Grubbs et al., 2019a, 2019b; Ravish et al., 2024). Yet there remains a high prevalence of anecdotal evidence for self-perceived “pornography addiction” in popular culture and online discourse (Chasioti & Binnie, 2021). Therefore, resolving the diagnostic status of PPU remains a key priority for both researchers and clinicians.

Prior research has linked PPU to depressed mood, decreased relationship connectedness (Cardoso et al., 2023; Lambert et al., 2012; Maitland & Neilson, 2023; Mestre-Bach & Potenza, 2023; Vaillancourt-Morel et al., 2024), increased anxiety, guilt, shame, loneliness, difficulty thinking, and suicidal thoughts (Cardoso et al., 2023; Fernandez et al., 2021; Guidry et al., 2020; Maitland & Neilson, 2023; McGraw et al., 2024; Mestre-Bach & Potenza, 2023), along with other psychosocial disorders (Chasioti & Binnie, 2021). Despite some evidence that pornography use can have a positive effect on attitudes towards sexuality (McKee, 2007; Rissel et al., 2017), it has also been associated with lower relationship satisfaction and commitment, especially when pornography use occurs without the partner’s consenting knowledge (Bechara et al., 2003; Floyd & Grubbs, 2022; Grubbs et al., 2022a, 2022b; Kohut et al., 2017; Lambert et al., 2012; Perry, 2016; Vaillancourt-Morel et al., 2024; Willoughby & Dover, 2024; Wright et al., 2017; Zitzman & Butler, 2009). The literature also suggests that PPU can significantly affect the user’s relationships with family, friends, and colleagues (Bridges & Morokoff, 2011; Fagan, 2009; Stack et al., 2004; Stewart & Szymanski, 2012). Hence, there are concerns over the societal and public health consequences of increasing pornographic consumption, regardless of its diagnostic status (Grubbs & Perry, 2019; Lambert et al., 2012).

It is important to account for masturbation when quantifying the effects of pornography use, as the two behaviors often co-occur but may also occur independently, with potentially distinct psychological and relational outcomes (Perry, 2020; Prause, 2017, 2019). The context in which masturbation occurs likely moderates its impact on mental health. For example, Perry (2020) found that once masturbation frequency was controlled for, the association between pornography use and both depression symptoms and decreased relationship satisfaction was reduced. Thus, differentiating these behaviors may help to clarify whether observed cognitive and emotional effects arise from visual stimulation, physical sexual release, or the interaction of these factors.

Yet behavioral mechanisms alone do not fully account for pornography-related distress. Recently, moral incongruence—defined as the internal conflict or distress that arises when an individual’s behavior violates their own moral, ethical, or religious values—has emerged as a key psychological factor in PPU (Grubbs & Perry, 2019; Grubbs et al., 2019a, 2019b, 2022a, 2022b; Lewczuk et al., 2020; Perry, 2018). A review by Floyd and Grubbs (2022) identified that moral incongruence regarding one’s own pornography use serves as a moderating factor for various pornography-related issues, such as emotional distress, relationship difficulties, and the sensation of addiction. Moral incongruence is influenced by multiple factors, including an individual’s religious beliefs, cultural norms, conservative sexual values, apprehensions about sexual exploitation, and the potential impact on interpersonal relationships (Chen et al., 2023; Hoagland et al., 2023; Ince et al., 2023; Lewczuk et al., 2021; Su et al., 2024).

However, a glaring issue remains: the psychological mechanisms linking pornography use to negative mental health outcomes have not yet been confirmed or quantified. While a substantial body of correlational research suggests such associations, and despite a growing number of longitudinal studies in this area (e.g., see Bőthe et al., 2022; Chen et al., 2022; Dawson et al., 2019; Kohut & Štulhofer, 2018; Leonhardt & Willoughby, 2018; Mattebo et al., 2018; McGraw et al., 2024; Milas et al., 2020; Muusses et al., 2015; Perry, 2017; Perry & Davis, 2017; Šević et al., 2020; Wright, 2012, 2013, 2023), few of these studies offer the temporal resolution needed to capture the affective and cognitive dynamics associated with pornography use and masturbation on a momentary basis. Some recent work has begun to address this limitation using experience sampling methods (Bőthe et al., 2020, 2021a, 2021b; Stark et al., 2024; Vaillancourt-Morel et al., 2020, 2024; Wordecha et al., 2018), but the field still lacks the necessary granularity to determine directionality—whether pornography use causes the associated mental health issues, results from them, or if the relationship is bidirectional. Without such data, conclusions about the causal impact of pornography on mental health remain speculative.

In summary, the causal relationship between moral incongruence, pornography use, and mental health remains unclear. Understanding the neuropsychological and behavioral mechanisms that drive the temporal variations in affective and cognitive dynamics around pornography use and masturbation is vital to clarify whether PPU is merely an impulse control disorder, or a true addiction that has elements of impulsivity. It will also help to enhance identification of clinically relevant thresholds for PPU.

Affective Chronometry

Many neuropsychological phenomena have a curvilinear decay, such as an exponential or power-law decrease, in response to a stimulus. Examples that unfold over several hours include memory retention (Candia et al., 2019; Kahana & Adler, 2017; Murre & Dros, 2015; Peterson & Peterson, 1959; Subirana et al., 2017; Wixted & Ebbesen, 1991) and emotional responses (Anderson & Adolphs, 2014; Botelho et al., 2018; Dejonckheere et al., 2020; Feidakis, 2011; Heller et al., 2015; Picard, 1997; Solomon & Corbit, 1974). These temporal dynamics can be measured using Ecological Momentary Assessment (EMA), a longitudinal methodology that collects real-time participant data about their thoughts, feelings, or actions, often multiple times a day (Bos et al., 2015; Shiffman & Stone, 1998). This approach, more broadly known as “affective chronometry”, tracks the timing of affective dynamics (Botelho et al., 2018; Davidson, 1998; Dejonckheere et al., 2020; Feidakis, 2011; Heller et al., 2015). For instance, Heller et al. (2015) used EMA to measure the decay of positive emotions after participants received different monetary rewards. Their findings indicated that participants’ emotional reactions approximated an exponential decay process over time, with the initial amplitude and decay rate correlating with brain activity in fMRI scans. This decay pattern is thought to result from how substances move between body areas, such as hormones and neurotransmitters moving through neural and vascular compartments (Ibarra et al., 2020).

We propose that curvilinear decay might be seen in individuals after engaging in pornography use or masturbation. By treating sexual activity as a stimulus that generates affective opponent processes in the body (Henry et al., 2023; Solomon & Corbit, 1974), we hypothesized that an EMA would allow us to observe and quantify both the emotional high during a sexual episode (the “a-process”), and the negative emotional after-effects (the “b-process”) (see Henry et al., 2023 for a more detailed explanation behind this theory). We also hypothesized that these after-effects would follow an exponential decay curve.

Aims of the Present Study

This study was exploratory in nature, and intended to evaluate the feasibility of quantifying temporal dynamics in the context of pornography use and masturbation in future research. The objectives were:

1. 1.

To model the temporal dynamics of pornography users in relation to sexual activities.

1. 2.

To determine whether moral incongruence moderated the temporal dynamics produced by pornography use and masturbation.

1. 3.

To evaluate the feasibility of conducting an EMA assessment of pornography users, in preparation for a larger cohort of future participants.

Method

Participants and Procedure

The study recruited participants through two methods: a pilot study at Auckland University of Technology, New Zealand, using flyers, followed by an exploratory study advertised on the r/pornfree subreddit, known for its anti-pornography stance (r/pornfree, 2022). The pilot study participants received $50 NZD gift vouchers, whereas the exploratory study participants volunteered without financial incentives due to funding limitations.

The study was delivered in two parts: a pre-EMA survey for collecting demographic and descriptive variables, followed by a four-week EMA to monitor temporal dynamics in relation to sexual activity. The pilot study participants also answered a post-EMA survey regarding their EMA experience. Despite different recruitment phases, the core survey questions were consistent between the two studies, allowing us to combine pilot data with the exploratory study data for the final analysis.

Inclusion criteria were proficiency in English; regular internet access and a compatible smartphone; use of pornography at least once in the past month; an