UNIVERSITY OF CALIFORNIA RIVERSIDE The Impact of Expressing Gratitude and Self-Improvement Behavior on Adolescents A Dissertation submitted in partial satisfaction of the requirements for the degree of Doctor of Philosophy in Psychology by Christina Nicole Armenta December 2017 Dissertation Committee: Dr. Sonja Lyubomirsky, Chairperson Dr. Katherine Sweeny Dr. Thomas Sy Copyright by Christina Nicole Armenta 2017 The Dissertation of Christina Nicole Armenta is approved: Committee Chairperson University of California, Riverside ACKNOWLEDGEMENTS Expressing gratitude leads people to feel motivated, efficacious, and competent and confident in their ability to meet their goals. I’ll admit that I have not expressed gratitude as often as the people in my life deserve, but the help and support I have received throughout my academic career has motivated and inspired me to be the best version of myself. This dissertation and my entire academic career would not have been possible without the wonderful people in my life. First and foremost, I would like to thank my advisor, Sonja Lyubomirsky. No one has contributed more to my thinking or research success. Under your tutelage, I learned to think more deeply, pay attention to details, and communicate more clearly. It still amazes me that you are able to effortlessly juggle seven grad students and send back drafts more quickly than I ever wanted them. You are an inspiration. Your unwavering support, encouragement, and guidance throughout the years has made me a much better writer, thinker, and researcher. Thank you for everything. Second, I would like to thank the other two members of my amazing dissertation committee: Tom Sy and Kate Sweeny. When I was an undergraduate at UC Riverside trying to figure out what I wanted to study, I happened to take an introductory psychology class taught by Tom Sy. His enthusiasm for psychology piqued my interest and ultimately contributed to my decision to switch my major to psychology—a decision from which I have never looked back. Tom and Kate gave me my first research assistant positions as an undergraduate. They opened my eyes to the world of research and helped me find my passion in positive psychology. It was my experience in these two labs that iv solidified my decision to go to graduate school. Thank you Tom and Kate for being the first to teach me the proper way to do research and for being on every one of my committees throughout graduate school. Third, I would like to thank my past labmates who have since gone on to do great things: Katie Bao, Joe Chancellor, Kristin Layous, and Katie Nelson. Thank you for setting the bar high and for showing me that work-life balance was possible. Kristin and Katie in particular played a huge role in helping me get into graduate school and transition from a research assistant to a full-blown researcher. Next, I would like to thank my current labmates: Peter Ruberton, Megan Fritz, Lilian Shin, Seth Margolis, Julia Revord, and Lisa Walsh. Our lab meetings will always hold a special place in my heart. It never ceased to amaze me how a newly fledged idea could turn into an amazing research project in the span of two hours. I am so grateful to have been a part of a group of supportive, brilliant colleagues and friends. Your feedback on this project and every other project I have ever been a part of has been invaluable. Thank you all for the laughs and discussions about everything from TV shows to the fate of social psychology. I would like to give a special shout-out to Peter for being a great friend and confidant. Thank you for never hesitating to drop everything to offer statistical or emotional support. I am so grateful I was able to go through graduate school with such a caring, supportive, and brilliant friend. I would also like to thank the staff at the Psychology Business Office, particularly Faye Harmer, Alesha Jaennette, and Renee Young. Each of you provided me emotional support and helped me overcome numerous challenges at various stages throughout v graduate school. Thank you for answering hundreds of my (annoying) questions without complaint and for always keeping your doors open. I would be remiss if I did not thank the Character Lab for funding this project and working with us to secure four amazing school partnerships. Furthermore, thank you to St. Genevieve High School, Harvard-Westlake School, Urban Assembly School for Emergency Management, and Mira Costa High School for participating in this study. A special thank you goes to each of the school coordinators and teachers who spent a great deal of time and effort ensuring that this study ran smoothly. This study would not have been possible without your help. I would also like to thank my parents, Proto and Frances Armenta, for their never- ending support and belief in me. I cannot thank you both enough for all you have done for me. Thank you for creating an environment where I was free to question everything and assert my opinions. You pushed me to think broadly and to never take anything for granted or settle for “good enough.” None of my accomplishments would have been possible without you. Furthermore, thank you to my brothers, Mark and David Armenta, for constantly making me laugh until my stomach hurts and for never making things easy and keeping me grounded. Finally, I would like to thank my husband, John Baumgardner. Words cannot express how grateful I am for your patience, love, and encouragement throughout the years. Thank you for always believing in me and motivating me to reach for bigger goals than I ever dreamed possible. I appreciate all the sacrifices you made to ensure that my vi dreams could become a reality. I am so lucky that I get to spend the rest of my life with you. I look forward to our next adventure! Portions of the Introduction to this Dissertation were previously published in: Armenta, C. N., Fritz, M., & Lyubomirsky, S. (in press). Functions of positive emotions: Gratitude as a motivator of self-improvement and positive change. Emotion Review. This research is based on work supported by the Character Lab and the National Science Foundation Graduate Research Fellowship Program. vii ABSTRACT OF THE DISSERTATION The Impact of Expressing Gratitude and Self-Improvement Behavior on Adolescents by Christina Nicole Armenta Doctor of Philosophy, Graduate Program in Psychology University of California, Riverside, December 2017 Dr. Sonja Lyubomirsky, Chairperson Surprisingly little research has investigated the motivating power of expressing gratitude. In a 4-week intervention, 9th and 10th grade students from four different high schools (N = 1,017) were prompted to write weekly letters to express gratitude either for a kind act, help with their academics, or help them with their health. Control participants listed their daily activities each week. All students then worked on improving themselves in kindness, academics, health, or organization skills. Immediately after expressing gratitude, participants felt more motivated than controls, more capable of improving themselves, and expressed greater intentions to muster effort towards self-improvement. Importantly, students who expressed gratitude for 4 weeks reported relatively greater life satisfaction and motivation to improve themselves over the course of the study, with these effects mediated by increases in connectedness, elevation, and indebtedness, and by reductions in negative affect. Students who expressed gratitude also reported relatively healthier diets over time and this effect was mediated by reductions in negative affect. Furthermore, males and those low in trait gratitude benefitted from gratitude the most. viii However, no group differences emerged in academic performance over time. This study provides evidence that gratitude is activating and energizing. Implications are discussed for how gratitude may be the key to keeping students motivated, healthier, and more satisfied with their lives over the course of a semester, and perhaps even their entire academic careers. ix TABLE OF CONTENTS Page List of Tables ................................................................................................................ xi List of Figures ............................................................................................................... xiv Introduction ................................................................................................................... 1 Method .......................................................................................................................... 15 Results ........................................................................................................................... 26 Discussion ..................................................................................................................... 44 References ..................................................................................................................... 54 x LIST OF TABLES Table # Title Page 1 Descriptive Statistics and Planned Contrasts for the Immediate 65 Emotional Effect of Expressing Gratitude at Time 1 2 Model Parameters (Standard Errors) and Goodness of Fit for Linear 66 Change for Improvement Motivation and Life Satisfaction from Baseline to Posttest 3 Model Parameters (Standard Errors) and Goodness of Fit for Linear 68 Change for Improvement Motivation and Life Satisfaction from Baseline to Follow-Up 4 Model Parameters (Standard Errors) and Goodness of Fit for Linear 70 Change for Grade Point Average (GPA)