1 Individual Differences in Sexual Self-disclosure: The role of Personality and Attachment in Romantic Relationships Beatriz Lopez Portillo Faculty of Science, School of Psychology The University of Sydney Primary Supervisor: Dr Niko Tiliopoulos Associate Supervisor: Dr Rebecca T. Pinkus A thesis submitted in fulfilment of the requirements for the degree of Doctor of Philosophy 2019 2 Statement of Originality I hereby certify that this thesis does not contain, without appropriate acknowledgement, any material previously submitted for a degree or diploma in any university. I also certify that this thesis does not contain, to the best of my knowledge, any material previously published or written by another person, except wherein reference is made. I also certify that the intellectual content of this thesis is the product of my own work and that all the assistance received in preparing this thesis and sources have been acknowledged. Beatriz Lopez Portillo 3 Acknowledgements First, I would like to thank my parents, Beatriz and Ruben. You are the reason why I have come so far. You have taught me to dream and to take challenges, even when they seem impossible to others. You have supported me even in my darkest times, and for that and more, I will always be thankful. There will never be words to express all my love and gratitude, ¡los amo! [Primero, quiero agradecer a mis padres, Beatriz y Rubén. Ustedes son la razón por la cual he llegado tan lejos. Ustedes me enseñaron a soñar y a afrontar los retos, aun cuando parecieran imposibles para otros. Ustedes me han apoyado hasta en mis momentos más oscuros, y por eso y más, siempre les estaré agradecida. Nunca tendré las palabras para expresar todo mi amor y gratitud, ¡los amo!] To my partner in crime, my “bestie,” my safe haven…Miško. This journey has been more than amazing, thanks to you. Thanks for being with me in the ups and downs, especially in the downs! Thanks for all the support you have given me, sometimes more of what I could ever ask. This thesis is yours as much as it is mine. I love you! To my primary supervisor, Dr. Niko Tiliopoulos, who not only nurtured me intellectually but also showed me that there is still “humanity” in academia. Thanks for going beyond the expected, for teaching me how to be a better scientist and a better human being. I clearly made a great decision choosing you as a supervisor and deciding to come so far just to be guided by you. No words or actions will ever repay all the emotional and intellectual support I have received from you in all these years (particularly at the end!). I would also love to thank my auxiliary supervisor, Dr. Rebecca T. Pinkus. Thank you for all the intellectual nurturing and for all the time and patience invested in me. I could not be any more lucky to have had you as a secondary supervisor. I have learned so much from you, that no words will lever repay all that work you have invested in me. 4 Thank you to Dr. Damian Birney, Professor Louise Sharpe, and Dr. Ilona Juraskova, who went the extra mile with me during these years. I find myself quite lucky to have been surrounded by such amazing researchers and human beings. Thank you for supporting me beyond what your role as Postgraduate Coordinator may request. To my sisters, Carla and Laura, that even from a distance, they manage to find the time to worry (and fight) with and for me (particularly with my “bestie” Conas). Thank you for the support, time invested, and for not leaving me alone in this crazy journey. Nothing more lovely than sister love! To my friends in Mexico and Australia (you know who you are). For being with me in the good and the bad times, for listening to me when I had a million complaints about this journey, and for keeping me in their lives. You know that I love you all! Finally, to all the guys in the ID Lab and the School of Psychology. Thank you for sharing ideas and making the Ph.D. less of a lonely journey. 5 Abstract This thesis offers new insights into the construct of sexual self-disclosure and its relationships with psychological factors such as personality and attachment (i.e., individual differences). Limited studies have been conducted on sexual self-disclosure (i.e., researchers have not made a distinction in how scripts might be affecting the self-disclosures of highly intimate topics, e.g., sexual topics). Therefore, further research may inform how individual differences contribute to the process of sexual self-disclosure in romantic relationships, how intimate interactions (e.g., trust and intimacy) influence such contributions and the relevance of examining this construct independently from general disclosure. Three studies were conducted to address this research question using self-report and interview methodologies. Throughout the studies, attachment avoidance was the consistent predictor of low levels of sexual self-disclosure, while open-mindedness and secure attachment were predictors of higher levels of sexual self-disclosure (SSD). It also appears that the country where individuals live (study 2 and 3) contributes to differences in associations between personality, attachment, and sexual self-disclosure, particularly in the relationships: anxiety-SSD and neuroticism-SSD. Moreover, individuals reported (study 3) that there are also interpersonal factors that affect their willingness to communicate personal sexual information, like perceived partner responsiveness and intimacy. Overall, these findings suggest that sexual self-disclosure is conceptually different from self-disclosure and must be treated independently. It emphasizes the relevance of conducting further research in order to create a uniform definition, and thus, create consistency in its measurement among literature. This thesis also contributes to the limited understanding of how intrapersonal (i.e., personality and attachment) and interpersonal factors (i.e., perceived partner responsiveness and intimacy) relate to the process of sexual self-disclosure in romantic relationships. 6 Table of Contents Statement of Originality ............................................................................................................. 2 Acknowledgements .................................................................................................................... 3 Abstract ...................................................................................................................................... 5 Table of Contents ....................................................................................................................... 6 Publications and Presentations related to this thesis ................................................................ 10 Publications .......................................................................................................................... 10 Conferences .......................................................................................................................... 10 List of Tables ............................................................................................................................ 12 List of Figures .......................................................................................................................... 13 Preamble ................................................................................................................................... 14 CHAPTER 1: Introduction ....................................................................................................... 17 Personality ................................................................................................................................ 18 Theoretical Models of Personality ....................................................................................... 19 Five-Factor Model (FFM) .................................................................................................... 20 Personality System. ....................................................................................................................... 21 Research in couples .............................................................................................................. 22 Adult Attachment ..................................................................................................................... 24 Attachment Theory: Basic concepts ..................................................................................... 24 Attachment styles. ......................................................................................................................... 26 Attachment in Adulthood ..................................................................................................... 26 Four-Category Model. ................................................................................................................... 27 Research in couples .............................................................................................................. 29 Sexual Self-disclosure .............................................................................................................. 31 Disclosure Reciprocity ......................................................................................................... 31 Synonyms. ..................................................................................................................................... 31 Definition. ...........................................................................................................................