Xiao, ZizhongA key predictor for romantic relationship quality is relationship optimism (also known as positive relationship expectations). However, relationship expectations can negatively affect relationship well-being when they become unrealistic and rigid, also known as dyadic perfectionism. The current research tests the effectiveness of a novel intervention that aims to improve relationship optimism and decrease dyadic perfectionism among couples. The four components of the intervention were based on previously validated social-psychological interventions that target relevant traits such as personal optimism and growth mindset. There were three intervention conditions. The first condition paired relationship optimism and dyadic perfectionism components together. The second condition only had the relationship optimism component. The third was the control condition. Results showed that despite a significant effect of the intervention on lowering immediate dyadic perfectionism, the intervention failed to have enduring effects on relationship optimism or dyadic perfectionism. Additionally, this intervention did not improve relationship quality on other indicators. Implications, broader impacts, and future directions based on the current results are discussed.enThesisSocial psychologyDyadic PerfectionismRelationship OptimismRelationship Well-being