Intimate relationships and olfaction - DiVA (PDF)

Intimate relationships and olfaction Body odors, adult attachment, and romance Anna Blomkvist Anna Blomkvist Intimate relationships and olfaction Doctoral Thesis in Psychology at Stockholm University, Sweden 2022 Department of Psychology ISBN 978-91-7911-698-9   Intimate relationships and olfaction Body odors, adult attachment, and romance Anna Blomkvist Academic dissertation for the Degree of Doctor of Philosophy in Psychology at Stockholm University to be publicly defended on Friday 4 February 2022 at 10.00 in hörsal 3, hus 2, Albano, Albanovägen 18. Abstract Odors influence several aspects of life, such as thoughts, memories, decisions, and emotions. Numerous studies have shown that human behavior can be affected by odors in different contexts. One such context is social relationships, in which body odors play a role. For example, previous studies have shown that close family members can identify each other’s body odors and prefer these compared to the body odors of non-family members. However, further research is needed to establish how body odors and olfactory functioning affect interpersonal behaviors and intimate relationships. In this thesis, I have conducted three studies highlighting the interplay between intimate relationships and olfaction. The overall purpose of this thesis was to investigate if and how olfaction is related to behaviors in intimate relationships. Study I tested if a romantic partner’s body odors have stress-altering effects and whether such effects differ depending on individual differences in romantic attachment security. As the practice of smelling a partner’s worn garment has been reported as a self-treatment against stress, my colleagues and I carried out an experiment to determine whether exposure to a partner’s body odor attenuates adult individuals’ subjective discomfort and psychophysiological responses. To induce discomfort and stress responses, participants were exposed to weak electric shocks while smelling their partner’s body odor (experimental condition) and three control odors (control conditions). The results showed that partner body odor had an attenuating effect on subjective discomfort during stress. Additionally, highly attachment-secure participants exhibited attenuated skin conductance specifically when exposed to their partner’s body odor. Thus, study I concluded that partner body odor is a scent of security, especially for relatively attachment-secure adults. Next, to determine whether olfaction is linked to sexual outcomes in intimate relationships, study II explored associations between self-reported olfactory functioning, on the one hand, and infidelity and sexual well-being, on the other, using a survey design. Our exploratory analyses found that self-reported olfactory function predicted sexual well-being positively and infidelity negatively, while controlling for other relevant socio-demographic variables. These results are discussed from a relationship science perspective, in which one’s intimate partner signifies sexual bonding in addition to caregiving and attachment. Thus, study II suggests that a partner’s body odor might be a scent of monogamy. Study III summarized the literature on populations with an impaired or total absence of a sense of smell. The interplay between olfaction and intimate relationship variables was examined by reviewing research reports and empirical studies concerning individuals with an impaired sense of smell. My colleague and I provided an overview of how olfactory impairment can impact three types of close social relationships: family relationships, friendships, and romantic relationships. For romantic relationships, which are the main focus of this thesis, three categories were defined in which olfactory impairment can impact close social relationships: eating, social support, and sexuality. Thus, study III concludes that olfactory ability is related to various romantic, intimate relationship behaviors. In sum, all three studies reported findings highlighting that olfaction (body odors and olfactory functioning) is related to intimate relationships. The results from the three studies are discussed via theoretical frameworks concerning the sense of smell, romantic relationships, and attachment. The thesis concludes that olfactory functioning and the experience of body odors are meaningful for intimate relationships and, as such, also for various behaviors in these relationships. Keywords: Intimate relationships, olfaction, body odor, attachment, sexual well-being, romantic relationships, infidelity, caregiving, intimacy, odors. Stockholm 2022 http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-196396 ISBN 978-91-7911-698-9 ISBN 978-91-7911-699-6 Department of Psychology Stockholm University, 106 91 Stockholm   INTIMATE RELATIONSHIPS AND OLFACTION Anna Blomkvist   Intimate relationships and olfaction Body odors, adult attachment, and romance Anna Blomkvist  ©Anna Blomkvist, Stockholm University 2022 ISBN print 978-91-7911-698-9 ISBN PDF 978-91-7911-699-6 Cover art by Fanny Gulliksson. Printed in Sweden by Universitetsservice US-AB, Stockholm 2021  1 Abstract Odors influence several aspects of life, such as thoughts, memories, decisions, and emotions. Numerous studies have shown that human behavior can be affected by odors in different contexts. One such context is social relationships, in which body odors play a role. For example, previous studies have shown that close family members can identify each other’s body odors and prefer these compared to the body odors of non-family members. However, further research is needed to establish how body odors and olfactory functioning affect interpersonal behaviors and intimate relationships. In this thesis, I have conducted three studies highlighting the interplay between intimate relationships and olfaction. The overall purpose of this thesis was to investigate if and how olfaction is related to behaviors in intimate relationships. Study I tested if a romantic partner’s body odors have stress-altering effects and whether such effects differ depending on individual differences in romantic attachment security. As the practice of smelling a partner’s worn garment has been reported as a self-treatment against stress, my colleagues and I carried out an experiment to determine whether exposure to a partner’s body odor attenuates adult individuals’ subjective discomfort and psychophysiological responses. To induce discomfort and stress responses, participants were exposed to weak electric shocks while smelling their partner’s body odor (experimental condition) and three control odors (control conditions). The results showed that partner body odor had an attenuating effect on subjective discomfort during stress. Additionally, highly attachment- secure participants exhibited attenuated skin conductance specifically when exposed to their partner’s body odor. Thus, study I concluded that partner body odor is a scent of security, especially for relatively attachment-secure adults. Next, to determine whether olfaction is linked to sexual outcomes in intimate relationships, study II explored associations between self-reported olfactory functioning, on the one hand, and infidelity and sexual well-being, on the other, using a survey design. Our exploratory analyses found that self-reported olfactory function predicted sexual well-being positively and infidelity negatively, while controlling for other relevant socio-demographic variables. These results are discussed from a relationship science perspective, in which  2 one’s intimate partner signifies sexual bonding in addition to caregiving and attachment. Thus, study II suggests that a partner’s body odor might be a scent of monogamy. Study III summarized the literature on populations with an impaired or total absence of a sense of smell. The interplay between olfaction and intimate relationship variables was examined by reviewing research reports and empirical studies concerning individuals with an impaired sense of smell. My colleague and I provided an overview of how olfactory impairment can impact three types of close social relationships: family relationships, friendships, and romantic relationships. For romantic relationships, which are the main focus of this thesis, three categories were defined in which olfactory impairment can impact close social relationships: eating, social support, and sexuality. Thus, study III concludes that olfactory ability is related to various romantic, intimate relationship behaviors. In sum, all three studies reported findings highlighting that olfaction (body odors and olfactory functioning) is related to intimate relationships. The results from the three studies are discussed via theoretical frameworks concerning the sense of smell, romantic relationships, and attachment. The thesis concludes that olfactory functioning and the experience of body odors are meaningful for intimate relationships and, as such, also for various behaviors in these relationships.  3 Svensk sammanfattning (summary in Swedish) Lukt påverkar flera aspekter av livet, såsom tankar, minnen, beslutsfattande (kognition) och känslor. Många studier har visat att mänskligt beteende kan påverkas av lukt i olika sammanhang. Ett sådant sammanhang är när människor möter andra, det vill säga sociala relationer, och där har tidigare studier visat att framför allt kroppslukt spelar en roll. Exempelvis har tidigare forskning visat att nära familjemedlemmar kan identifiera varandras kroppslukt och föredrar dessa jämfört med kroppslukten hos icke- familjemedlemmar. Emellertid krävs ytterligare forskning för att undersöka och fastställa hur kroppslukter och luktfunktion påverkar interpersonellt beteende och intima relationer. I denna avhandling har jag genomfört tre studier som belyser samspelet mellan lukt och intima relationsvariabler. Det övergripande syftet med denna avhandling var att undersöka om och hur lukt är relaterat till beteenden i intima relationer. I studie I testades huruvida stressförändrande effekter av partnerns kroppslukt existerar och om dessa varierar beroende på anknytningsvariationer i ett intimt romantiskt förhållande. Eftersom beteendet att dofta på en partners klädesplagg rapporteras som en självbehandling mot stress, undersökte mina kollegor och jag med hjälp av ett experiment huruvida exponering för en partners kroppslukt dämpar vuxnas subjektiva obehag och psykofysiologiska svar på stress. Deltagarna presenterades för sin partners kroppslukt samt tre kontrollukter medan de utsattes för svaga elektriska stötar för att framkalla obehag och stressreaktioner. Resultaten visade att partnerns kroppslukt minskar subjektivt obehag under stress. Dessutom uppvisade relativt anknytningstrygga deltagare dämpade psykofysiologiska stressreaktioner, i form av hudkonduktans, när de utsattes för partnerns lukt. Studie I konkluderade med att partnerlukt är en doft av trygghet, särskilt för mer anknytningstrygga vuxna. För att undersöka hur lukt är relaterat till sexuella utfall i intima relationer undersökte studie II om och hur självrapporterad luktfunktion är associerad med otrohet och sexuellt välbefinnande. Medan tidigare studier har visat att luktfunktion spelar en viktig roll för att knyta an i ett romantiskt förhållande, undersökte mina kollegor och jag det möjliga sambandet mellan självrapporterad luktfunktion, sexuellt välbefinnande och otrohet genom en  4 enkätstudie. Våra analyser fann att självrapporterad luktfunktion predicerade sexuellt välbefinnande positivt och otrohet negativt, även då vi kontrollerade för andra variablers påverkan. Dessa resultat diskuteras i ett relationsvetenskapligt perspektiv, där den ena partnern i ett intimt förhållande signalerar mer än bara omsorg och anknytning, även sexuella funktioner. Studie II indikerar att en partners lukt kan vara en doft av monogami. Studie III sammanfattade litteratur om populationer med nedsatt eller en total frånvaro av luktsinne. Samspelet mellan lukt och intima relationsvariabler undersöktes genom att vi granskade forskningsrapporter och empiriska studier. Jag och min kollega summerade tre typer av nära sociala relationer: familjeförhållanden, vänskap och romantiska relationer. Det sista förhållandet är mest centralt i denna avhandling. För romantiska relationer formulerades tre kategorier genom vilka luktfunktionsnedsättning kan påverka romantiska relationer: ätbeteenden, socialt stöd och sexuella beteenden. Studie III drar slutsatsen att luktfunktion är relaterat till olika romantiska, intima förhållandebeteenden. Alla tre studierna rapporterade resultat som visar på att lukt (kroppslukt och luktfunktion) är relaterat till intima relationer och en rad olika beteenden. Jag diskuterar forskningsresultaten från de tre studierna utifrån teoretiska ramverk om luktsinnet, romantiska relationer och anknytning. Sammanfattningsvis ger denna avhandling insikter om att luktfunktion och upplevelsen av kroppslukt är betydelsefulla för intima relationer.  5 Acknowledgements I am a middle child. I believe that Jeff Kluger has stated in his book that middle children often connect with others and create families outside the biological family. I am fortunate enough to be one of those middle children with several families besides my biological one. At a moment like this when I can acknowledge who has helped me reach my goal and complete this thesis, it seems reasonable to thank all of these family members. They have all been supportive, questioned my choices of research questions to everyday habits, and expanded my views in so many areas. I am very grateful to have all these people in my life. First, to my academic family in Norway: Maria, Eva, Rakel, Hilde, and Katrine. Without your encouragement and eagerness to study psychology, which was contagious, I am not sure that I would have continued on this study path, so thank you. To my master study family – Katinka, Fanny, Alexander, and Rebecca – thank you for being sarcastic in relation to articles, for explaining that certain things are unreasonable according to ideology, and for all the happy moments of nonsense we have shared over great meals. To my dear attachment group family at Stockholm University, which I am fortunate to call my home lab. Joel, Mårten, Tommie and Aaron, thank you for always being cheerful and encouraging individuals who dare to step outside your comfort zone when it comes to academic discussions. I have really cherished every weekly meeting with you. To my second academic home family at Karolinska Institute and the perception lab. Mats, Janina, Danja, Moa, Evelina, Arnaud, Robin, Artin, Behzad, and Martin, what an inspiring group of achievers you are. Always pushing each other, yourselves, and me to become great scientists, it has been a pleasure to be a part of your lab. To my dearest supervisor team family: Marco, Johan, and Pehr. How fortunate that you are all more than decent fellows who could share the rather heavy responsibility of walking me through this academic path to completing my  6 Ph.D. I want to thank you for not being super-stressed but reasonably chill, for not being controlling but rather flexible in your guidance, and, lastly, for always standing by my side and encouraging me to do what I think would be the best. To my large Ph.D. student family at Stockholm University: Max, Diana, Lilian, Hellen, Sebastian, Nichel, Andreas, Marta, Philip, Miriam, Joanna, Ingela, Kristina, Henrik, and Alexander. Meeting every day for lunch or a fika or some after work drinks has been key for making this period of my life joyful and meaningful. To my academic inspiring family of collaborators, guides, and mentors: Mehmet, Torun, Maria, Jonas, Elisabeth, Katarina, Lilianne, Laura, Margareta, Charlotte, Robert, Therese, and Per. Thank you for believing in my research ideas, giving me teaching responsibilities above my academic rank, including me in your work, and showing me that a career in academia is possible, exciting, and enjoyable with varying tasks and many possibilities. To my inclusive family in the United States: Regina, Maya, Patrese, Marlise, Tina, Megan, Brittney, Drew, Poppy, Cait and Landree. My six months in New York would not have been half as fun or half as challenging in terms of learning new technical and social skills without you. Thank you for giving me space to develop those skills and a place to stay and call home. To my academic Italian family – Antonio, Maria, and Giulia – thank you for including me in your team and showing me that science can be a creative process that is more insightful when combining different research fields. To my Finnish family – Johan, Laura, Monika, Eva-Maria, and Kaj – thank you for giving me much-needed energy boosts during summers on Åland with you and your children. I also want to thank Marianne and Åke, two encouraging family members whom I miss very dearly. To my half-Belgian and Norwegian friend family: Mikaela, Tina, Henriette, Ida, Johanna and Kristoffer, Cecilia and Pär, Karin, Benjamin, Mari, Blake, Janni, Marius, Sigrid, Henrik, Sissel, and Christine. Thank you for asking me how my work is going and for accompanying me on adventures. But mostly thank you for giving me new perspectives through brilliant book recommendations, podcast tips, and amusing and intellectual conversations. To my dear friend family – Anna, Katta, Becca, Diana, Henrik, Rickard, Markus, and Rob – your endless support and love keep me going and inspire me to seek new questions in both my daily and academic life. Thank you for being there and standing next to me in my saddest times and in the most ridiculous and hilarious moments.  7 To my extra family – Jan, Sirpa, Linda, Oscar, Malin, Edith, and Ruth – thanks for welcoming me to your family and grounding me in that having a Ph.D. degree will not make me unique in your family. Thank you for your encouragement. To my real biological family: Mum and Dad, Grandpa and Grandma, Elin and Dennis, Mattias and Ellen, Gabriel, Philp, and Siri. How incredibly fortunate and lucky I am to be born into our family. Every brave step I have made along the way, whether it concerns presenting at a huge international conference or simply believing in myself is partly because of you. Spending time with you cheers me up, pushes me rhetorically, questions the path I am on, and so much more. My greatest thanks go to you all. Lastly to my companion and champion, Daniel. Nothing can compare to your intense willpower and never-ending support and questioning, and I love every second of it. Thank you for being my attachment figure. I smell you.