Rationale --------- Across two independent cross-sectional studies of heterosexual romantic dyads we have found consistent evidence of significant positive interactions between actors' and partners' solitary pornography use when predicting sexual and relationship satisfaction. These interactions suggest that sexual and relationship satisfaction are lower when couples are discordant rather than concordant in pornography use (or non-use). These effects hold after controlling for couples frequencies of shared pornography use and do not appear to be moderated by gender (see [Study 1][1], [Study 2][2]). In one of these samples, this interaction effect also extends to the predictions of sexual communication and intimacy / closeness (Kohut, Balzarini, Fisher, & Campbell, in prep). We have previously argued that this effect may be the result of spurious correlations that may be rooted in similarities and differences in sex drive, erotophilia/erotophobia, or sexual attitudes. Indeed, we have some support for this perspective; in one cross-sectional sample, the association between actors' erotophilia/erophobia and sexual / relationship satisfaction was moderated by partners' erotophilia/erotophobia in a pattern that was very similar to what we had previously found with actors' and partners' pornography use. In competitive models this interaction effect reduced the predictive value of the interaction between actors' and partners' solitary pornography use when predicting sexual and relationship satisfaction, but did not eliminate it entirely. The current study seeks to extend this line of inquiry by predicting sexual satisfaction with actors' and partners' attitudes towards pornography in a longitudinal sample of heterosexual couples. Method ------ The data come from an 8-wave longitudinal study of 135 newlywed couples provided by Michelle Russell and Dr. James McNulty. The eight assessments occurred approximately every 6 months. Attitudes towards pornography was only measured at Time 5. The specific question asked participants to indicate their agreement with the item, “I enjoy viewing pornography,” using a scale that ranged from 1 = very strong disagreement to 7 = very strong agreement. Sexual satisfaction was assessed with the Hudson Index of Sexual Satisfaction. Preliminary Analysis -------------------- Independent of Kohut et al's initial forays into this research area, Russell and McNulty conducted unregistered analyses of this dataset with a similar rationale in mind. For example, a dyadic growth curve analysis of the index of sexual satisfaction was conducted using measures from times 5, 6 , 7, and 8 (coded in ascending order, with Time 5 coded 0). This model further regressed the intercept and slope parameters estimated from the time model onto husbands' attitudes towards pornography, wives' attitudes towards pornography, and their interaction. A positive interaction emerged on the intercept, such that own attitudes were more positively associated with own satisfaction when the partner also had more positive attitudes. The simple effect of own attitudes towards pornography was positive, though not significant, among people with partners 1 SD above the mean on attitudes and significantly negative among those with partners 1 SD below the mean on attitudes. Significant effects for attitudes did not emerge in the slope component of the model, indicating that time 5 attitudes towards pornography were unrelated to change in sexual satisfaction from time 5 to time 8. Predictions / Research Questions -------------------------------- H1: On the basis of previous findings, and preliminary results, we expect that partners' attitudes towards pornography will moderate the association between actors' attitudes towards pornography and sexual satisfaction such that satisfaction will be lower when actors and partners are discrepant in their sexual attitudes. H2: We have previously found that the interaction between actor and partner solitary pornography use wholly accounts for gendered actor and partner effects of solitary pornography use. Given our previous findings, we do not believe that the actor, partner, or actor by partner interaction effects involving attitudes towards pornography will be further moderated by gender. RQ1: While our position is that the "effects" of pornography use in our previous models may be spurious, many contributors to the "harms-effects" literature (see Kohut, Campbell, & Fisher, 2016) would assume that pornography plays a causal role in the deterioration of relationships. Given these divergent perspectives, it seems prudent to consider the possibility that attitudes towards pornography may moderate the trajectory of sexual satisfaction over time. - To the extent that attitudes are correlated with solitary pornography use, a "harm-based" approach would argue that positive attitudes may "enhance" the decline in sexual satisfaction over time (as more positive attitudes reflect more pornography use which is the assumed determinant). Such a perspective would be supported by evidence that sexual satisfaction over time is negatively moderated by attitudes towards pornography use. - From an attitudes similarity perspective, however, alternative expectations are possible. In a newlywed couple, for example, one might expect that full awareness differences in attitudes between partners may have yet to fully emerge, especially with respect to attitudes towards sexual interests like pornography use. If that were true, the expected positive interaction between partners' attitudes towards pornography should *increase* over time reflecting increasing negative impacts of discordance in attitudes (relative to concordant attitudes) as partners learn more about one another. - On the other hand, few people wait until marriage to begin a sexual relationship with one another these days, so partners may already be aware of similarities / differences in each others attitudes towards pornography (or other closely related attitudes). In such circumstances, the interaction between partners' attitudes towards pornography use will either remain constant across time or decrease over time, depending largely on the (a) stability of attitudes and (b) the stability of the relationships between attitudes towards pornography and sexual satisfaction. The results of the preliminary analysis suggest that the actor by partner interaction effect is likely consistent over time. RQ2: In our previous samples, we have been unable to find quadratic effects along the line of incongruence (see Shannock et al. 2010) between actors' and partners' pornography use. Such a pattern is relevant to the argument of concordance / discordance as positive interactions in a regression analysis tends to force the prediction of the midspace of the predicted plane to lie between the points of discordance and points of extreme concordance (concordant non-use of pornography and concordant use of pornography) resulting in a "saddle-shaped" plane of prediction. In the context of a positive interaction between actor and partner effects, a curvlinear line of incongruence has the potential to partially or fully mitigate this "dip" in the model. Due to the distribution of pornography use data that has been collected to date, predictions in this midspace (as well as the points of high frequency concordance) have had relatively large standard errors. This has made it difficult to determine if this dip represents a statistically significant deviation along the line of concordance in out previous data sets, though formal tests suggest not. As attitudes towards pornography are generally less skewed than pornography use behaviour, this data presents an opportunity to revisit this issue. [1]: https://osf.io/9kjup/ [2]: https://osf.io/fqqte/