Overview
- Researchers from the Weizmann Institute and collaborators reanalyzed century-spanning records of twins and long-lived siblings from Sweden, Denmark, and the United States.
- By filtering out extrinsic mortality such as accidents, violence, pandemics, and other non–aging causes, the team calculated lifespan heritability at roughly 50–55%, higher than widely cited 20–25% figures.
- The study reports heterogeneity by cause of death, with the weakest genetic signal for cancer and the strongest for dementia in the cohorts that included cause-specific data.
- Independent experts praised the work as methodologically important but warned that results depend on modeling choices and that intrinsic versus extrinsic deaths can be difficult to distinguish.
- The authors and commentators stressed limits to generalizability from largely northern European and selected long-lived groups and emphasized that environment, lifestyle, healthcare access, and chance still play major roles.