Diverging Paths to the Self: The Distinct Psychological Roles of Nostalgia and Declinism in Personal Growth

We investigated how nostalgia and declinism, two distinct forms of past-oriented reflection, differentially relate to personal growth. In preregistered cross-sectional Study 1 (<i>N</i> = 810, Chinese sample), we measured nostalgia using three instruments: the Southampton Nostalgia Scale (SNS), the Nostalgia Inventory (NI), and the Personal Inventory of Nostalgic Experiences (PINE). Although SNS- and NI-based nostalgia were positively associated with personal growth and uncorrelated with declinism, PINE-based nostalgia was positively linked to declinism and unrelated to growth. Canonical correlation analysis further indicated conceptual overlap between PINE items and declinism. In experimental Study 2 (<i>N</i> = 360, Chinese sample), we manipulated nostalgia and declinism with the Event Reflection Task to test their causal effects. Compared to a control condition, nostalgia increased personal growth, but declinism reduced it. Collectively, the findings highlight the importance of measurement in nostalgia research and underscore the psychological distinction between nostalgia and declinism. Accurately capturing the tone and function of nostalgic reflection is essential to understanding its influence on the self, motivation, and well-being.