Twin data suggests genetics plays bigger role in lifespan than previously thought

Using decades of twin data from Denmark and Sweden, researchers estimate that genetics account for about 55% of lifespan variation after removing extrinsic causes of death, with lifestyle and environment making up the remaining ~45%. The findings imply a possible genetic ceiling to human lifespan, though no single longevity gene exists and lifestyle still matters. The study calls for larger, more diverse datasets to confirm whether this genetic limit holds across populations.