Introduction
Pornography is defined as any written or visual material with explicit sexual content to sexually arouse the audience [1, 2]. Research in the field of pornography use is important due to its high prevalence and negative consequences [3, 4]. Previous studies have focused on the prevalence [8, 9], effects [10, 11], dynamics [12], and situational variables of pornography use [13, 14]. 
The use of pornography, particularly violent pornography, can lead to negative sexual attitudes and behaviors [18, 19]. Although consumption of violent pornography is relatively uncommon [20], studies have shown its positive relationship with sexual aggression, especially verbally [21]. This correlation raises concerns about potential negative consequences of violent pornography. However, there is limited information about individuals’ preferences for different pornographic content, from violent to submissive content. Further research is needed to understand the preferences and potential effects of different types of pornography on individuals and society. 
The types of pornography scale (TPS) is a tool that contains a comprehensive list of pornography types (n=27) based on the frequently searched terms [23]. This scale measures the level of sexual arousal using a Likert scale. The TPS can be used to provide more detailed and accurate information about the consumption patterns of different types of pornography. Since there is no scale in the Persian language to measure the use of different types of pornography, the present study aims to investigate the psychometric properties and factor structure of the Persian version of TPS for the Iranian population.

Methods
This is a descriptive psychometrics study. Participants were 500 people aged 18-49 years (mean=23.55±5.07 years), including 318 males and 182 females, who were selected using a convenience sampling method. The inclusion criteria were: Pornography use (based on the self-report), age>18 years, and declaring consent to participate in the study. Those who had not responded to more than 5% of the questions were excluded from the study. To prepare the Persian version of TPS, the back-translation method was used. After ensuring the proper translation of the tool into the Persian language, its content validity was examined by Lawshe’s method. Descriptive statistics (mean and percentage) were used to describe the data. Confirmatory factor analysis (CFA) and exploratory factor analysis (EFA) were used to determine the construct validity, while the convergent validity was assessed using the problematic pornography use scale (PPUS). Cronbach’s α was used to check internal consistency. The data were analyzed in SPSS software, version 23 and LISREL software, version 8.8.

Results
According to the obtained results, since content validity ratio≥0.8 is the acceptable level [29], the content validity of the Persian TPS was confirmed. The CFA did not confirm the 3-factor model. The values of fit indices are presented in Table 1.


Seven factors were confirmed by EFA using principal component analysis with varimax rotation, having a factor load greater than 1. These seven factors together could explain about 60% of variance in the total score of TPS (Table 1). Cronbach’s α and Omega values for the whole scale was 0.87 and 0.86, respectively. The total score of the PPUS had a positive and significant relationship with all factors of the TPS. Therefore, the Persian TPS had good convergent validity (Table 2).


Therefore, it can be said that the Persian TPS has acceptable reliability and validity for the Iranian population.

Discussion
This study aimed to investigate the psychometric properties of the Persian TPS. The results showed that it had good content validity and was understandable for the respondents. The CFA results did not confirm the 3-factor model of TPS. The EFA demonstrated seven factors for the Persian version, three of which were identical to those of original version including group sex, homosexual and bisexual theme (non-heterosexual sex), and violent theme (non-mainstream paraphilic content). Pornography consumption and attitudes towards pornographic content vary significantly across different cultures and societies [23, 30, 31]. It seems that the existence of these differences resulted in the emergence of more factors in the Persian version compared to the main version of TPS, highlighting the influence of cultural and social factors. The results of convergent validity showed that the total score of PPUS had a positive and significant relationship with most factors of the Persian TPS. This finding is consistent with the results of previous findings [32, 33]. The Cronbach’s α coefficient was acceptable and close to the value reported for the original instrument in Hald and Stulhofer’s study [23].
Our study had some limitations. Due to the taboo of sexual topics, particularly pornography, in Iran, participants’ responses may be biased. To reduce the bias, the study used online anonymous sampling and emphasized confidentiality of the participants. The high number of questions may cause fatigue in the respondents. To address this, participants were motivated by offering them a monetary reward and the chance to enter into a lottery at the end of the study.

Conclusion
The Persian version of TPS has good validity and reliability to measure the use of different types of pornography content in the Iranian population.

Ethical Considerations
Compliance with ethical guidelines
This study has ethical approval from the University of Social Welfare and Rehabilitation Sciences (Code: IR.USWR.REC.1401.032).

Funding
This research did not receive any grant from funding agencies in the public, commercial, or non-profit sectors.

Authors contributions
Supervision: Hamid Poursharifi; Conceptualization, methodology, data analysis, preparing the initial draft, review & editing: Bahar Dehghanpour Hanzaei; investigation and resources: Milad Kodkhoda and Fateme Sadat Raeisian.

Conflicts of interest
The authors declared no conflict of interests.

Acknowledgments
The authors would like to thank the professors from the clinical psychology department of the University of Social Welfare and Rehabilitation Sciences and all the participants for their cooperation in this study.


References

1. Husain W, Qureshi Z. Preferences in marital sexual practices and the role of pornography. Sexologies. 2016; 25(2):e35-41. [DOI:10.1016/j.sexol.2016.01.005]
2. Malamuth NM, Addison T, Koss M. Pornography and sexual aggression: Are there reliable effects and can we understand them? Annual Review of Sex Research. 2000; 11:26-91. [PMID]
3. Kohut T, Balzarini RN, Fisher WA, Grubbs JB, Campbell L, Prause N. Surveying pornography use: A shaky science resting on poor measurement foundations. Journal of Sex Research. 2020; 57(6):722-42. [DOI:10.1080/00224499.2019.1695244] [PMID]
4. Döring N, Mohseni MR. Are online sexual activities and sexting good for adults’ sexual well-being? Results from a national online survey. International Journal of Sexual Health. 2018; 30(3):250-63. [DOI:10.1080/19317611.2018.1491921]
5. Lewczuk K, Wójcik A, Gola M. Increase in the prevalence of online pornography use: Objective data analysis from the period between 2004 and 2016 in Poland. Archives of Sexual Behavior. 2022; 51(2):1157-71. [DOI:10.1007/s10508-021-02090-w] [PMID] [PMCID]
6. Pornhub Insights. Pornhub’s 2013 Year in Review [Internet]. 2023 [Updated 2023 October 23]. Available from: [Link]
7. Pornhub Insights. The 2019 Year in Review [Internet]. 2023 [Updated 2023 October 23]. Available from: [Link]
8. Peter J, Valkenburg PM. Adolescents’ exposure to sexually explicit material on the Internet. Communication Research. 2006; 33(2):178-204. [DOI:10.1177/0093650205285369]
9. Wright PJ. U.S. males and pornography, 1973-2010: Consumption, predictors, correlates. Journal of Sex Research. 2013; 50(1):60-71. [DOI:10.1080/00224499.2011.628132] [PMID]
10. Braithwaite SR, Coulson G, Keddington K, Fincham FD. The influence of pornography on sexual scripts and hooking up among emerging adults in college. Archives of Sexual Behavior. 2015; 44(1):111-23. [DOI:10.1007/s10508-014-0351-x] [PMID]
11. Hald GM, Malamuth NN. Experimental effects of exposure to pornography: The moderating effect of personality and mediating effect of sexual arousal. Archives of Sexual Behavior. 2015; 44(1):99-109. [DOI:10.1007/s10508-014-0291-5] [PMID]
12. Sabina C, Wolak J, Finkelhor D. The nature and dynamics of internet pornography exposure for youth. Cyberpsychology & Behavior. 2008; 11(6):691-3. [DOI:10.1089/cpb.2007.0179] [PMID]
13. Hald GM. Gender differences in pornography consumption among young heterosexual Danish adults. Archives of Sexual Behavior. 2006; 35(5):577-85. [DOI:10.1007/s10508-006-9064-0] [PMID]
14. Hald GM, Mulya TW. Pornography consumption and non-marital sexual behaviour in a sample of young Indonesian university students. Culture, Health & Sexuality. 2013; 15(8):981-96. [DOI:10.1080/13691058.2013.802013] [PMID]
15. Kamalzadeh L, Alavi K, Salehi M. [Comorbidity of bipolar disorder and multiple paraphilias: A case report (Persian)]. Iranian Journal of Psychiatry and Clinical Psychology. 2015; 21(1):69-74. [Link]
16. Ogas O, Gaddam S. A billion wicked thoughts: What the world’s largest experiment reveals about human desire. New York: Dutton; 2011. [Link]
17. Ogas O, Gaddam S. A billion wicked thoughts: What the internet tells us about sexual relationships. New York: Dutton; 2012.[Link]
18. Hald GM, Malamuth NM, Yuen C. Pornography and attitudes supporting violence against women: Revisiting the relationship in nonexperimental studies. Aggressive Behavior. 2010; 36(1):14-20. [DOI:10.1002/ab.20328] [PMID]
19. Rostad WL, Gittins-Stone D, Huntington C, Rizzo CJ, Pearlman D, Orchowski L. The association between exposure to violent pornography and teen dating violence in grade 10 high school students. Archives of Sexual Behavior. 2019; 48(7):2137-47. [DOI:10.1007/s10508-019-1435-4] [PMID]
20. Baer JL, Kohut T, Fisher WA. Is pornography use associated with anti-woman sexual aggression? Re-examining the confluence model with third variable considerations. The Canadian Journal of Human Sexuality. 2015; 24(2):160-73. [DOI:10.3138/cjhs.242-a6]
21. Wright PJ, Tokunaga RS, Kraus A. A meta-analysis of pornography consumption and actual acts of sexual aggression in general population studies. Journal of Communication. 2016; 66(1):183-205. [DOI:10.1111/jcom.12201]
22. Sun C, Miezan E, Lee NY, Shim JW. Korean men’s pornography use, their interest in extreme pornography, and dyadic sexual relationships. International Journal of Sexual Health. 2015; 27(1):16-35. [DOI:10.1080/19317611.2014.927048]
23. Hald GM, Štulhofer A. What types of pornography do people find arousing and do they cluster? Assessing types and categories of pornography in a large-scale online sample. Journal of Sex Research. 2016; 53(7):849-59. [DOI:10.1080/00224499.2015.1065953] [PMID]
24. Hald GM. Gender differences: Behavioral, situational, and interpersonal patterns of pornography consumption. Generation P. 2007; 118-32. [Link]
25. Hald GM, Seaman C, Linz D. Sexuality and pornography. In: Tolman DL, Diamond LM, Bauermeister JA, George WH, Pfaus JG, . Ward LM, editors. APA handbook of sexuality and psychology, Vol. 2. Contextual approaches. Washington: American Psychological Association. [DOI:10.1037/14194-001]
26. Bentler PM, Chou CP. Practical issues in structural modeling. Sociological Methods & Research. 1987; 16(1):78-117. [DOI:10.1177/0049124187016001004]
27. Kor A, Zilcha-Mano S, Fogel YA, Mikulincer M, Reid RC, Potenza MN. Psychometric development of the Problematic Pornography Use Scale. Addictive Behaviors. 2014; 39(5):861-8. [DOI:10.1016/j.addbeh.2014.01.027] [PMID]
28. Darvish Molla M, Nikmanesh Z. [Psychometric properties of the persian version of problematic pornography use scale (pornography addiction) (Persian)]. Psychological Methods and Models. 2017; 8(27):49-63. [Link]
29. Hambleton RK. The next generation of the ITC test translation and adaptation guidelines. European Journal of Psychological Assessment. 2001;17(3):164-72. [DOI:10.1027//1015-5759.17.3.164]
30. Rowland DL, Uribe D. Pornography use: What do cross-cultural patterns tell us? In: Rowland DL, Jannini EA, editors. Cultural differences and the practice of sexual medicine: A guide for sexual health practitioners. Berlin: Springer International Publishing; 2020. [DOI:10.1007/978-3-030-36222-5_18]
31. Ahorsu DK, Adjorlolo S, Nurmala I, Ruckwongpatr K, Strong C, Lin CY. Problematic porn use and cross-cultural differences: A brief review. Current Addiction Reports. 2023; 10:572-80. [DOI:10.1007/s40429-023-00505-3]
32. Hanseder S, Dantas JAR. Males' lived experience with self-perceived pornography addiction: A qualitative study of problematic porn use. International Journal of Environmental Research and Public Health. 2023; 20(2):1497. [DOI:10.3390/ijerph20021497] [PMID] [PMCID]
33. Willoughby BJ, Dover CR. Context matters: Moderating effects in the associations between pornography use, perceived addiction, and relationship well-being. Journal of Sex Research. 2022; 1-14. [DOI:10.1080/00224499.2022.2148155] [PMID]
34. von Andrian-Werburg MT, Klopp E, Schwab F. Fantasy made flesh-a network analysis of the reciprocal relationship between sexual fantasies, pornography usage, and sexual behavior. The Journal of Sex Research. 2023; 1-15. [DOI:10.1080/00224499.2023.2170964]
35. Peter J, Valkenburg PM. Adolescents’ exposure to sexually explicit material on the Internet. Communication Research. 2006; 33(2):178-204. [DOI:10.1177/0093650205285369]