Within‐person dynamics of physiological and perceived stress among South African youth in positive youth development programs - Roya Abbasi‐Asl; Natasha Keces; Richard M. Lerner; Margaret Mackin; Ruoying Zhang; Elizabeth M. Dowling; Jonathan M. Tirrell; Alexa Hasse; Kirsten Olander; Angela Larkan; Chuma Mashita; Raah Msimango; et al. (Applied Psychology: Health and Well-Being, 2026)