Pre-Registration: You and I - The Role of Inclusion of Other in the Self for Couple’s Sexuality in Germany

Introduction One of the most influential theories on interpersonal closeness is the self-expansion theory of inclusion of other in the self (IOS) by Aron, Aron and Smollan (1992). In self-expansion theory and the corresponding measure – IOS scale – relationship closeness is operationalised as the degree to which an individual includes aspects of the partners self into the own self-concept and thereby adopts a we-perspective. IOS has been incorporated into couple’s research regularly, and it has been found, that greater IOS is an important factor for relationship quality, well-being, satisfaction and pair-bonding (Branand, Mashek, & Aron, 2019; Frost & Forrester, 2013; Le et al., 2010; Tsapelas, Aron, & Orbuch, 2009). In the past ten years IOS has also been used in sex research, with results indicating positive relations with sexual functioning, desire and frequency (Muise et al., 2019; Witherow et al., 2017). Although some promising results on the relationship between IOS and couple’s sexuality exist, the relationship between IOS and sexual satisfaction and functioning is still to be investigated. Research Objective and Hypotheses The focus of the current research will be to investigate the relationship between IOS, sexual satisfaction, and sexual functioning. H1: IOS is positively related to individual’s sexual satisfaction. H2a: Relationship duration, love, orgasm occurrence, and IOS are associated with sexual satisfaction for men and women. H2b: Relationship duration, love, and IOS are associated with sexual satisfaction for men and women with sexual dysfunctions. H3: IOS is negatively related to how strongly someone is affected by experiencing sexual difficulties. Participants and procedure Analysis will be conducted with data collected for the first nationwide broadly representative sex survey in Germany GeSiD – German Health and Sexuality Data. For GeSiD, 4,955 participants, aged 18-75 years, were interviewed in 200 sample points across Germany. The survey was conducted as household face-to-face interviews, using computer assisted personal interviews (CAPI) and computer assisted self interviews (CASI) for the more intimate questions. The questionnaire was conducted in German, therefore participants had to be German speaking residence. Topics included information on sexual behaviour, sexual attitudes, sexual relationships and experiences, and sexual and reproductive health. Due to the higher risk for sexually transmitted infections (STI), young adults aged 18-35 were oversampled. Participants received a total of 30 € as a token of appreciation. The sampled size was calculated for sufficient statistical power for a broadly representative survey, especially for gender-separated analyses of smaller effects or specific groups. For the present analyses only participants in committed couple relationships are included. Data collection was executed by the social research institute Kantar Emnid. Authors had no prior insight into the data during the collection process until they were presented with an anonymous and weighted data file. Some preliminary analyses have since been calculated on other research questions (e.g. sexual orientation and discrimination) than presented in this registration. None of the following analyses described, have been conducted with the GeSiD data before submission of the pre-registration. Measures (1) Relationship status was assessed by “are you currently in a long-term relationship?”, with the answer possibilities being 1) No; 2) Yes, with a heterosexual partner; 3) Yes, with a homosexual partner; 4) Yes, with more than one person. We did not define long-term relationship more strictly, but let the participants decide for themselves. If answered with yes (Answers 2 to 4) participants were forwarded to a chapter on the current relationship, while those who answered with 1 were forwarded to a single life chapter. For all analyses only participants will be considered who self-define as being in a relationship (regardless of said relationship being heterosexual, homosexual or polyamorous). (2) Sexual difficulties are surveyed following the ICD-11 criteria for sexual dysfunctions. Women were queried for tensions or pain during sexual intercourse, difficulties to reach orgasm, reduced response to sexual stimuli, and reduced sexual desire. Men were queried for premature ejaculation, difficulties to reach orgasm, erection difficulties, and reduced desire for sex. The screener used to measure sexual dysfunction according to ICD-11, was developed in cooperation with the responsible experts of the WHO (Word Health Organisation). First, the relevant criteria of the ICD-11 were translated into German to create the screener. Second, it was translated back into English to be reviewed and cleared by the responsible coordinator of the WHO. The aim was to develop a screener that is as short as possible and at the same time provides valid information on the diagnoses of sexual dysfunctions. Men and women respectively were asked for each sexual problem individually and whether they have ever experienced it over a period of several months. For each named difficulty participants were asked how much they were affected by it on a five-point Likert scale (H3); whether they have always had it; whether they had experienced the difficulty within the past twelve months; and whether this problem occurred always or only in specific situations. Participants, who stated to have experienced any of the named ICD-11 dysfunctions over a period of several months were considered to have a sexual difficulty or problem. Participants who additionally stated, that they were strongly or very strongly affected by said difficulty/problem were identified as having a sexual dysfunction. The focus of this initial research (H2b) will be participants in relationships who stated at least one sexual dysfunction within the past 12 months. (3) Inclusion of other in the self is measured with the IOS scale by Aron, Aron and Smolland (1992); a pictorial measure, with seven more and more overlapping pairs of circles (comparable to venn-diagrams). The circles are translated into a seven-point Likert scale where higher results indicate more closeness. (4) Relationship duration is assessed in months with the question “how long have you and (…) been together?” (5) Love is measured by the question: “Do you love (…)”, with the answer categories being a five-point Likert scale from 1) not at all (any longer), to 5) absolutely. (6) Sexual satisfaction is measured for the past 12 months by asking the participants to rate the following four statements on a five-point Likert scale from 1) does not apply at all; to 5) totally applies: a) All things considered, I am satisfied with my sex life; b) I would like to have more sex than I’ve had recently; c) I would like to receive more caressing (kissing, cuddling, stroking, touching) than I’ve had recently; d) My sex life is not varied enough. (7) Orgasm occurrence was measured only for participants who have had sexual intercourse within the past 12 months with “did you have an orgasm the last time you had sex?”. Analyses Analyses will be conducted using complex samples method with SPSS. Hypotheses H1 and H3 will be calculated as bivariate Pearson correlations. Research has shown, that IOS scale results are mostly right skewed, i.e. participants evaluate their relationships as mostly being very close. In case we cannot assume normal distribution of the IOS scale, Spearman’s correlation will be used to confirm the results of the Pearson correlation. For multiple regression analyses (H2a and H2b), sexual satisfaction will be treated as the dependant variable. For H2b, sexual dysfunction will be included into the multivariate model as interaction term with IOS. Relationship duration, love, orgasm occurrence and IOS will be treated as independent variables for multiple regression analyses. Depending on the definition, the concept of love and relationship closeness can overlap. Therefore, the independent variables love and IOS will be analysed for multicollinearity. Similarly, due to expected high correlations between sexual dysfunction and the occurrence or non-occurrence of orgasm, this variable is not included as an independent variable for analysis of H2b. Limitations The GeSiD data were weighted to match the German population in terms of age, gender, education, nationality and geographic region. Nonetheless, when comparing the GeSiD data to other representative health surveys in Germany and reviewing the non-response questionnaires, we found that the general health status in the GeSiD data is systematically overestimated. References Aron, A., Aron, E. N., & Smollan, D. (1992). Inclusion of other in the self scale and the structure of interpersonal closeness. Journal of personality and social psychology, 63(4), 596. Branand, B., Mashek, D., & Aron, A. (2019). Pair-bonding as Inclusion of Other in the Self: A literature review. Frontiers in psychology, 10, 2399. Frost, D. M., & Forrester, C. (2013). Closeness discrepancies in romantic relationships: Implications for relational well-being, stability, and mental health. Personality and Social Psychology Bulletin, 39(4), 456-469. Le, B., Dove, N. L., Agnew, C. R., Korn, M. S., & Mutso, A. A. (2010). Predicting nonmarital romantic relationship dissolution: A meta‐analytic synthesis. Personal Relationships, 17(3), 377-390. Muise, A., Harasymchuk, C., Day, L. C., Bacev-Giles, C., Gere, J., & Impett, E. A. (2019). Broadening your horizons: Self-expanding activities promote desire and satisfaction in established romantic relationships. Journal of personality and social psychology, 116(2), 237. Tsapelas, I., Aron, A., & Orbuch, T. (2009). Marital boredom now predicts less satisfaction 9 years later. Psychological Science, 20(5), 543-545. Witherow, M. P., Chandraiah, S., Seals, S. R., Sarver, D. E., Parisi, K. E., & Bugan, A. (2017). Relational intimacy mediates sexual outcomes associated with impaired sexual function: examination in a clinical sample. The journal of sexual medicine, 14(6), 843-851.