This study explored characteristics of young adults' solidarity during the Covid-19 pandemic by identifying three different profiles, characterized by low (23%), average (54%), and high solidarity (23%). Based on longitudinal Swiss panel data (N T1 = 797, M age T1 = 12.15 years, 51% female; 28% migration background representing diverse ethnicities; N T2 = 707, M age T2 = 15.33 years; N T3 = 596, M age T3 = 18.31 years), the study combined person-and variable-centered approaches to examine whether sympathy, social trust, and peer exclusion at earlier phases in development predicted membership in pandemic-related solidarity profiles (N T4 = 300, M age T4 = 20.33 years). All developmental predictors were significantly associated with the likelihood of expressing solidarity during the pandemic as young adults.This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.