Exposure to Pornography and Adolescent Sexual Behavior: Systematic Review

Introduction

Adolescence (ages 10-19 years) is a period of marked physical, cognitive, and psychosocial development [1]. Curiosity and experimentation are common in the context of adolescent psychosexual development [2], and adolescents who experience healthy relationships are more likely to have healthy relationships in their young adulthood [3]. However, some sexual behaviors can increase the risk of sexually transmitted infections or unplanned pregnancy [4]. Examples include earlier age of first sexual experience, condomless sex, or sex with multiple partners [5]. Studies have also suggested that teen dating violence, including sexual aggression in adolescence, is linked to substance abuse problems, depression, and psychosis [6]. Hence, studying the factors associated with these types of sexual behaviors in adolescence is crucial for understanding how to best support the healthy development of adolescents.

In adults and older populations of young adults, quantitative studies have demonstrated associations between pornography exposure and behaviors such as sex with multiple partners and condomless sex and sex during intoxication [7,8]. Qualitative and mixed methods studies have also supported this association [9-12]. In the era of en masse digitalization and the widespread use of smartphones and other readily accessible digital media, exposure to pornography has become ubiquitous [13]. Studies in Australia [8] and the United States [14] suggest that adolescents are exposed to pornography by the age of 13 years on average for males and 17 years for females despite laws prohibiting showing or supplying pornography for those aged <18 years [15-18]. This raises concerns as to whether exposure to pornography influences sexual behavior during adolescence.

As noted in a review by Peter and Valkenburg [19] in 2016, there has been increasing empirical research on this subject area. However, whether pornography exposure is causally associated with sexual behavior in adolescence remains contentious [19-23]. It has been argued that adolescents are aware of the shortcomings and artificiality of pornography, hence the impact on sexual behavior is limited [9], whereas others have argued the converse, claiming that pornography exposure is a strong predictor of earlier age of first sex, sexual aggression, and other sexual behaviors [24], as well as a platform upon which adolescents develop their sexual identities and relationships [25]. Previous systematic reviews of the evidence focused on college students [24] and adolescents diagnosed with porn addiction [26] and did not consider some potentially important sexual behaviors such as paid sex [19]. We sought to update the Peter and Valkenburg [19] review in the era of ubiquitous smartphones by systematically reviewing the empirical literature measuring exposure to pornography and its associations with sexual behaviors in adolescents in the general population.

Methods

Overview

We conducted a systematic review of quantitative studies that examined the associations between exposure to pornography and sexual behaviors in adolescents aged between 10 and 19 years. We followed the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines (Figure 1 and Multimedia Appendices 1 and 2) [27,28]. This systematic review was registered with the International Prospective Register of Systematic Reviews (PROSPERO registration number: CRD42021227390).

We searched 6 databases: CINAHL (via EBSCOhost), Cochrane Reviews (via Ovid, see Multimedia Appendix 3 for specific Cochrane databases searched), Embase (via Ovid), MEDLINE (via Ovid), PsycINFO (via Ovid), and Web of Science (all databases: Web of Science, Current Contents Connect, BIOSIS Previews, CAB Abstracts, and MEDLINE). The search strategy, developed in MEDLINE and later adapted to other databases, used controlled vocabulary and free-text terms that related to the 2 key concepts of adolescents and pornography (Multimedia Appendix 3) as appropriate for each database. The search strategy, including adaptations, was developed by an experienced specialist research librarian. By design, search terms did not include “preteen*” and “prepubert*” because these terms were considered less likely to yield studies about young users of pornography than about child pornography (see Inclusion and Exclusion Criteria). Similarly, the names of apps were not included as search terms, because the apps are used not only for pornography by our definition (in subsequent section) but also for interactive sexual experiences. The searches were limited to peer-reviewed papers published from January 1, 2010, to November 30, 2022, to update a previous review article [19]. Other studies that were found to be independent of our search strategy were identified through citation searches.

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Inclusion and Exclusion Criteria

To be considered eligible, studies must have reported quantitative empirical findings on the association between exposure to pornography and sexual behavior outcomes (Table 1). Qualitative studies and systematic reviews were excluded from analysis. For this review, exposure to pornography was defined as a participant’s report of any contact with sexually explicit or erotic media (pornography), with the intent of sexual arousal [29]. We included studies that did not define the exposure but used synonymous terms such as “sexually explicit material,” “adult or X-rated material,” or “pornography” without defining it in the methods. We excluded studies on child pornography, that is, sexually explicit or erotic material portraying individuals aged <18 years.

Sexual behavioral outcomes included those with established associations with adverse health and social outcomes (Table 1). Studies describing sexual aggression were limited to those that measured forced or coercive penetrative sex, excluding those that reported only on forced or coercive kissing and touching or used only the term “sexual acts” without further specification. Composite indices of sexual behaviors were excluded, as the association could not be clearly mapped to a specific behavior. The included studies were limited to those with adolescent participants (aged 10-19 years, inclusive), in which the age range was not provided, and the reported mean or median age was within this range. Included studies were those from a general population sample, and studies with clinical or specific population groups (eg, juvenile detention) were excluded. There was no restriction on the ethnicity of the participants or the study country. Multiple studies that analyzed the same cohort were considered together if they reported different associations.

Data Extraction

The first author (PP) conducted the search and removed duplicates using EndNote X9 [30]. PP reviewed the titles and abstracts (N=5852) and reviewed the full text (n=337) for eligibility (Figure 1). In cases of doubt (n=7), another author (SRS) was consulted. A total of 19 studies were eligible for inclusion. Information about the study location, design, sample size calculation, participants, setting, exposures, outcomes, control variables, methods of statistical analysis, effect sizes, and their variations were extracted by PP and MR. Where possible, effect sizes were calculated from the data if not reported through the study. Included studies either reported on sex or gender. For this systematic review, we used male/female/nonbinary gender or male/female sex to describe the gender or sex of the cohorts as reported in each study.

Quality Assessment

Study quality was assessed independently by the authors PP and MR using the Newcastle-Ottawa Scale [31]. For the Newcastle-Ottawa scale used to assess longitudinal studies, we replaced the item “was follow-up long enough for outcome to occur” with “whether the outcome was assessed to be at low levels at baseline.” Cross-sectional studies were assessed based on the representativeness of the sample, sample size, addressing the influence of nonrespondents on the reported effect estimates, exposure, and outcome, reporting of statistical analyses, and comparison of outcome and control groups (Multimedia Appendix 4 [32-50]). Longitudinal studies were assessed based on the representativeness of the sample, selection of a nonexposed cohort, assessment of exposure, outcome (at baseline and subsequent waves), follow-up rates, and comparability of outcome and control groups (Multimedia Appendix 4). In cases of conflicts, 2 other authors (ML and JM) were consulted. Low risk of bias was classified as a score of ≥7, moderate risk of bias as a score of 4 to 6, and high risk of bias as a score of 0 to 3.

Results

Included Studies

Initial searches identified 5852 abstracts, and 19 studies met the inclusion criteria (Figure 1). This included 11 cross-sectional studies [32-42], 2 case-control studies [43,44], and 6 prospective cohort studies [45-50]. Furthermore, 8 studies addressed early age (<16 years) of first sex [32,34,35,40,41,43,48,50]; 5 studies addressed sexual behaviors including condomless sex [37,42,46,47,49]; 2 studies examined multiple sexual partners during lifetime; a single study examined group sex [35]; 3 studies examined coercive or forced sex [33,39,41]; and 5 studies examined other behaviors including paid sex [38,41,45], teenage pregnancy [44], and history of sexually transmitted infections [36].

The included studies were conducted across 13 countries (Multimedia Appendix 4), and 2 studies were conducted internationally across various countries in Europe [33,40] (Multimedia Appendix 4). Most studies were conducted in European countries (n=9) [33,35,40,41,45,46,48-50], followed by countries in Asia (n=6) [32,36,38,43,44,47], the United States (n=3) [37,39,42], and Eastern Uganda (n=1) [34]. Ten studies reported on the frequency of pornography exposure [33,35,37,38,41,45,46,48-50], and of these studies, one [33] reported “regular” exposure without further definition. Four studies reported exposure to different pornography contents [35,37,39,42], including violent pornography (aggressive sexual acts) and pornography with condomless sex (Multimedia Appendix 4). Exposure to pornography was not uniformly measured; 7 studies did not define pornography in their methods [32,33,35,41,43-45] and a further 6 studies defined it as “sexually explicit content,” “adult content,” “banned media,” or “R-rated media” [34,36-38,40,47] (Multimedia Appendix 4). Similarly, the definitions of outcomes varied across studies. Age at first sex was measured prospectively in one study by asking at each follow-up whether an adolescent had ever had sexual intercourse [50] and retrospectively in 2 studies by asking the age at first sexual intercourse [35,41]. Another longitudinal study assessed the outcome of the first sexual experience in a sexually naive population at baseline, with a mean age at baseline of <16 years [48]. Four studies had a mean sample age of <16 years, so any participant in these samples who had sexual intercourse was considered to have had a young age of first sex [32,34,40,43]. “Multiple sexual partners” included an adolescent self-reporting sex with more than one partner over their lifetime (n=2) [46,47] and having ever participated in group sex (n=1) [35]. Studies of forced or coercive sex included participants as perpetrators (n=3) [33,39,41] and survivors (n=2) [33,39]. Studies of paid sex included participants as buyers (n=3) [38,41,45] or sellers (n=2) [41,45]. Because of the heterogeneity in how exposure and outcomes were measured across studies, a meta-analysis was not possible.

Early Age of First Sex

A total of 8 studies (2 prospective cohorts, 1 case-control, and 5 cross-sectional) assessed the relationship between pornography exposure in adolescence and earlier age of first sex (defined as below the age of 16 years; Table 2 [32,34,35,40,41,43,48,50]). Of the 6 cross-sectional studies that examined this outcome, 2 studies [35,41] assessed only male adolescents, whereas the other 4 studies [32,34,40,43] studied cohorts of both males and females and the analysis was not stratified by sex. Two prospective cohort studies reported conflicting findings regarding this association. The first study, of 639 male adolescents, conducted in Belgium [50] found a positive longitudinal relationship between exposure to pornography and an earlier age of first sex. The second study [48] reported no association between exposure to pornography and an earlier age of first sex in the overall sample. However, adolescents with a later age of first exposure to pornography had a significantly lower probability of reporting first sexual experience in subsequent waves than their counterparts with earlier exposure to porn. Subsequent sensitivity analyses to account for missing values showed no major association between the timing of porn exposure and first sex in males but showed an association between regular exposure to porn versus no exposure and first sex in females [48]. Both studies were assessed to have a low risk of bias. Four cross-sectional studies of low to moderate risk of bias conducted in Sweden [35], Thailand [32], Eastern Uganda [34], and 23 EU countries [40] supported this association. Two studies did not identify any substantial associations. In 2013, Sahay et al [43] presented a P value close to the threshold and conjectured that the rarity of the outcome in their sample limited the power to detect a true association.

Condomless Sex

A total of 5 studies (3 prospective cohorts, 1 case-control, and 1 cross-sectional) assessed the relationship between pornography exposure in adolescence and participation in condomless sex (Table 3 [37,42,46,47,49]). Two studies [37,42] were conducted in the United States, and one each in Croatia [46], Taiwan [47] and the Netherlands [49]. The largest study assessing this outcome was a prospective cohort study of 2054 participants conducted in Taiwan [47], and the smallest was a cross-sectional study of 206 participants conducted in the United States [37]. Of the 2 cross-sectional studies that examined this outcome, one studied a cohort of male adolescents [37], whereas the other examined a cohort of males and females, where analysis was not stratified by gender [42]. The 3 longitudinal studies reported cohorts of male and female adolescents, where the analysis was not stratified by sex. However, one study [46] included gender as an interaction term to analyze the effects of gender on the association, while another [47] adjusted for gender in the regression models.

The results of these studies were mixed. Among 3 longitudinal studies [46,47,49], one conducted in Taiwan [47] reported a positive association and was assessed to have a moderate risk of bias, while the studies from Croatia and the Netherlands [46,49] reported no major associations and were assessed to have a low risk of bias. Both cross-sectional studies supported a positive association between exposure to pornography and condomless sex in the samples [37,42]. Nelson et al (2019) examined pornography patterns in non-heterosexual male adolescents [40], a study that was assessed to have a low risk of bias. Specifically, this study found that those who viewed more condomless sex (>50% of total pornography viewed) were more likely to have reported participating in condomless sex [37]. Another cross-sectional study that found an association, by Wright et al [42], was assessed to have a high risk of bias owing to poor adjustment of confounders and ascertainment of exposures and outcomes.

Multiple Sexual Partners

Two prospective studies examined the association between pornography exposure and multiple lifetime sexual partners [46,47]. These studies were conducted in Croatia [46] and Taiwan [47]. Both studies examined male and female cohorts. Koletić et al [46] included gender as an interaction term to analyze the effects of gender on the association, whereas Lin et al [47] adjusted for gender in the regression models. The study by Lin et al, 2020 [47] found an association between pornography exposure and multiple sexual partners and was assessed to have a moderate risk of bias owing to not measuring the outcome at baseline, having a low proportion of the sample reporting the outcome, and limited assessment of follow-up and retention rates (Table 3). This study reported exposure to pornography across different media (such as comic books and web sites) in a single exposure variable. Koletić et al [46] found a major association but only in a nonadjusted model. A single cross-sectional study conducted in Sweden on a cohort of male adolescents reported a nonsignificant association between exposure to pornography and participation in group sex [35], that is, sex with multiple partners simultaneously (Tables 1 and 3).

Forced or Coercive Sex

A total of three cross-sectional studies [33,39,41] assessed the relationship between pornography exposure in adolescence and experiences of forced or coercive penetrative sex (Table 4). These studies were conducted in the United States [39], Sweden [41] and 5 European countries [33]. The largest study was by Barter et al [33] in 2021 of 3277 adolescents, and the smallest was conducted by Rostad et al [39] in 2019 with 1766 adolescents. Furthermore, 2 out of 3 studies reported a major positive association in reported experiences of forced or coercive sex in males only [33,39]. Two of the 3 studies [33,39] stratified their analyses as male or female, and one of the studies examined only male adolescents [33].

Paid Sex

The relationship between pornography exposure and “paying for sex” was inconsistent (Table 4). Studies have been conducted in Singapore [38], Sweden [41], and Switzerland [45]. A prospective cohort study [45] reporting this exposure and outcome found a positive association between exposure to pornography and sex. This was supported by one [38] of the 2 cross-sectional studies [38,41] that examined this association. There are an insufficient number of studies examining both male and female adolescents to conclude whether this association was gender dependent, as both Ng et al [38] and Svedin et al [41] reported on male adolescents yet found opposing substantial associations. Regarding the outcome of selling sex, a prospective cohort study found no association with pornography viewing [45]. However, they reported an interaction effect with gender, whereby females with high pornography consumption were more likely to sell sex than those with low consumption. One cross-sectional study [41] that sampled only male adolescents found a positive association between selling sex and viewing pornography. There are an insufficient number of studies examining this association to draw conclusions.

Sexual Health Consequences

One study reported a major association between exposure to pornography and teenage pregnancy [44], whereas another found an association with a history of sexually transmitted diseases [36] (Table 4). The study of teenage pregnancy was assessed to have a moderate risk of bias, largely due to poor assessment of nonrespondents and limited justification of sample size. Both studies were limited by a lack of representative samples.

Discussion

We identified 19 papers published in the past 10 years that reported the association between pornography exposure and sexual behaviors in adolescents. Our review found that exposure to pornography in adolescence is associated with an earlier age of first sex (below 16 years of age). Notably, recent studies with higher-quality evidence supported the existence of a relationship between exposure to pornography and earlier age of first sex for adolescents aged 10-19 years. Out of the studies, 4 cross-sectional studies [32,34,35,40] and 1 longitudinal study found this association. Two cross-sectional studies did not report a significant association, with the study by Sahay et al [43] limited by a low proportion of the population reporting the outcome, and the study by Svedin et al [41] limited by the retrospective nature of the reported outcomes and the era in which data collection occurred (before access to smartphones and high-resolution internet video). Another longitudinal study by Matković [48] also found inconsistent associations between pornography exposure and age of first sex, depending on how the exposure was measured (timing and quantity) and the gender of the adolescent. However, these were not consistently present in all analyses. The study was limited by the baseline mean age of the sample being 15.8 (SD 0.5) years and the fact that sexual debut soon after this age would be expected. A review by Peter and Valkenburg in 2016 [19] also reported an association between pornography exposure and earlier age of sexual activity, and our review has strengthened this finding with the inclusion of additional, more recent studies. We did not find an association between exposure to pornography and any other sexual behaviors. Notably, a positive association between exposure to pornography and earlier age at first sex in adolescence does not imply a causal relationship, even when a temporal association is identified, as in a longitudinal study [50]. For example, adolescents who are more interested in sexual activity and therefore more likely to become sexually active may also be more likely to view pornography because of their interest in it. Both Donevan et al [35] and Svedin et al [41] reported higher exposure to pornography in those seeking it as a source of inspiration or knowledge about sex.

There was a limited number of studies, mainly cross-sectional, examining the relationship between exposure to pornography and forced sex, paid sex, multiple partners, teenage pregnancy, and history of sexually transmitted infection [33,35-39,41,42,44-47,49]. There is clearly a need for more longitudinal studies to determine whether exposure to pornography is associated with other sexual behaviors in adolescents. In contrast to previous reviews [19,26], we examined forced penetrative sex separately from sexual aggression (aggressive intentions or coerced nonpenetrative sexual behaviors such as kissing or touching). We found mixed results, which might be clarified if the studies were to report these outcomes separately. We excluded some studies [22,51,52] where forced sex was measured only as “forced sexual acts” and hence accounted for forced sexual behaviors that are strictly not forced sexual intercourse, such as kissing or touching against one’s will. It is also worth noting that one study included in this review found an association between exposure to pornography and forced sex [39] focused specifically on violent pornography, defined as any erotic media depicting individuals being forced into sexual acts. A recent meta-analysis found that violent pornography was modestly correlated with sexual aggression and noted difficulties in interpreting the data owing to citation biases and researcher expectancy effects [53]. In addition, a systematic review conducted in 2021 aligned with our observations, noting the difficulty of clarifying the association between pornography consumption and nonconsensual acts such as rape [54]. This may differ from the impact of nonviolent pornography, which has been associated with reduced sexual aggression in older populations [11,53,55]. It is possible that exposure to violent pornography is associated with sexually aggressive behavior.

Before considering the significance of our findings, we recognize that our systematic review was not without its limitations, particularly the potential for missing literature. This may have been the case because our choice of search terms and databases was not sent for external peer review [27,28], and we excluded grey literature. However, using a wide array of databases spanning across multiple disciplines (Multimedia Appendix 3), consulting with an expert librarian, and searching citations of included articles, we conducted a comprehensive search to address the aims of this review. This review included studies from 13 different countries and 2 cross-national European studies (Appendix 4). Most studies were conducted in high-income Western settings. For multiple lifetime sexual partners, no major association with pornography exposure was found when the study was conducted in a Western country (Croatia) [46], but there was an association in an Eastern country (Taiwan) [47]. A similar pattern was identified for the outcomes of group sex, teenage pregnancy, and history of sexually transmitted infections (Tables 3 and 4), yet there are insufficient studies examining or comparing culturally diverse locations to draw conclusions. The role of cultural influence on the relationship between pornography exposure and sexual behaviors is under-studied in adolescents, but this review suggests that country and culture may be important. Several articles assessing the relationship between exposure to pornography and outcomes of sexual behavior in older populations have suggested the significance of cultural context as an influence on how susceptible an individual is to adopt the sexual scripts prescribed in pornography [56-58]. In certain cultures, where access to sexual health education is limited, adolescents tend to use pornography as one of the few sources of sexual health knowledge [59]. It is possible that in societies without sex education, adolescents may more readily adopt sexual scripts presented in pornography [60,61], normalizing sexual behaviors depicted in pornography. Despite this conjecture, the role of culture in adolescents’ exposure to pornography and its relationship with sexual behaviors remains unknown, and further studies are recommended.

Inconsistent findings on the association between exposure to pornography in adolescence and sexual behavior also likely reflect the limitations of research studies. Consistent with a previous review [19], we found that exposure to pornography was not assessed in a uniform or reproducible manner (Multimedia Appendix 4). Nearly half of the studies did not define pornography in their methods, and a further 5 studies defined it simply as “sexually explicit content,” “adult content,” or “banned material.” A lack of specificity in exposure may impact a study’s ability to identify an existing association. It also prevents the pooling of data in a meta-analysis, limiting the ability to increase the power to detect an association. There is a clear need to standardize the definition and quantification of pornography. Two studies identified that adolescents commonly reported using pornography as an information source [35,41]. Such ideas align with previous findings that adolescents learn about sex, sexual identities, and sexuality through pornography [9,62]. Pornography content, perceptions of that content, frequency of use, and reasons for use are important dimensions of pornography exposure. A consistent and reliable measurement of these dimensions will help elucidate the pathways between pornography and sexual behavior in adolescents. In addition, as in the case of studies assessing sexual aggression indicative of forced sex (Table 4 and Multimedia Appendix 4), questionnaires assessing sexual behaviors require careful piloting and validation to ensure that they are understood by adolescents as intended. Furthermore, statistical analyses that do not combine forced sex with other sexually aggressive acts into one outcome can help to further clarify the observed associations. A review of how sexual aggression has been measured and reported thus far in the literature could help clarify the literature on pornography use and its associations with forced sex. To further clarify the nature of the observed associations, studies should also control for baseline confounders, such as access to or the quality of sexual health knowledge received by adolescents. While we recommend further research to develop more reliable and robust measures of exposure and outcomes, we also recognize that this type of research on adolescents’ behavior presents ethical barriers. There is a high level of moral concern in society regarding the potentially harmful influence of pornography on adolescents, including among research participants. This concern is likely to translate into barriers to the approval and funding of research on this topic.

Most studies in this review were not inclusive of adolescents who were sexuality or gender-diverse. It has also been reported that same-sex-attracted male adolescents use pornography to negotiate their sexual identity, learn about the mechanics of sex and performance, and define ideas of pain and pleasure [63]. Another study found that sexuality diverse adolescents used social media to share sexual information [64]. Hence, it is possible that pornography may have different associations with sexual behaviors in sexuality diverse adolescents than in cisgender heterosexual peers. We recommend studies on sexual behaviors and their relationship to pornography in sexuality and gender-diverse adolescents.

Recent findings [65] suggest that sexual attitudes mediate the relationship between pornography exposure and sexual behavior. Recent studies in the United States [66] have found that adults use pornography as a source of sex information. In college students, studies suggest a mediating role of sexual education in the relationship between exposure to pornography and sexual behaviors [67-69]. It is possible that individuals are most strongly influenced by pornography when they have limited access to sex education. Therefore, supporting international guidelines [70], we also recommend that sex education be school based, universal, comprehensive, accurate, evidence informed, and age appropriate.