It is well-known that social participation contributes to health. Emerging evidence also suggests that musical and artistic groups uniquely promote emotional well-being, socialization, and engage multiple cognitive functions. In this regard, the intervening and preventative capacities of artistic social groups ought to be considered to a greater extent, especially in light of increased population aging. The present research examined three artistic interventions among complex-care patients, individuals with dementia, and their caregivers. Three larger studies were also conducted to determine associations among different social groups, social identities (e.g. artistic, sport, religious), and various well-being outcomes, and to explore the potential moderating role of genetic polymorphisms in the relationships between groups and health. In Study 1, complex-care patients who listened to personalized music playlists reported fewer negative emotions, increased life satisfaction, and greater self-esteem over time compared to controls. Among people living with dementia and their caregivers in Studies 2 and 3, an artistic reminiscence program and music-making intervention strengthened relationships between carers and their care recipients, encouraged socialization between group members, and supported wellbeing. Studies 4 and 5 further investigated differences across social group types and revealed that artistic and educational social groups explained the greatest amount of variation in depression, memory, and executive functioning compared to other social groups. Yet, in Study 6, for retirement home residents and students, social identification was more strongly correlated with well-being than social participation alone. Moreover, overall group identity was positively correlated with telomere length among older adults. Interestingly, there was a positive association between group memberships and perceived social status for homozygous carriers of an IGF-1 SNP (rs7136446). Among older and younger adults, there was also a positive BIOPSYCHOLOGICAL EFFECTS OF SOCIAL PARTICIPATION ON AGING III correlation between group identification and health among carriers of the BDNF Met allele (rs6265), and an inverse relationship between group identification and depressive symptoms among carriers of an FGF-2 SNP (rs1048201). Taken together, participating in social groups, notably those involving music or the arts, appeared to confer health benefits among older adults. Knowledge of these associations can be used to help personalize future social interventions for older adults with the aim of maximizing their benefits. Behind every study presented here is a story of new friendships, challenges, triumphs, and inspiration, backed by a large team of individuals without whom this research would not have been possible. At the forefront are my supervisors, Dr. Renate Ysseldyk and Dr. Hymie Anisman. They meticulously combed through every research proposal and study design that amounted to this body of work, of which I am very proud. Renate's comp...