Meaning in life and biological functioning: A multisystem synthesis and agenda for future research

Meaning in life (MIL) has been reliably linked to healthier aging, lower disease risk, and reduced mortality across large epidemiologic cohorts, yet the biological processes that accompany these associations remain poorly characterized. This Review synthesizes evidence across five systems-genomic, neurobiological, endocrine, autonomic, and inflammatory-to clarify how MIL aligns with patterns of biological functioning. Genomic studies suggest modest heritability and preliminary neural relevance, though specific molecular pathways remain uncertain. Neuroimaging findings indicate that MIL corresponds to features of large-scale network organization, particularly within the insula, default mode network, and limbic circuitry. Endocrine and autonomic studies report associations between MIL and cortisol rhythms, stress recovery, and patterns of sympathetic and parasympathetic activity. Inflammation-related research provides the most consistent evidence, with higher MIL associated with lower chronic inflammatory markers and, in limited cases, indicators of more effective immune functioning. Together, these findings indicate that MIL has been associated with variation in biological markers across multiple systems. Nevertheless, most evidence is cross-sectional, and directionality remains unresolved. Future work using longitudinal, experimental, and intervention-based designs will be essential for determining when, how, and under what conditions MIL is reflected in biological processes.