Heritability of Intrinsic Human Life Span Is About 50% When Confounding Factors Are Addressed
3rd February 2026
Many researchers have tried to understand longevity in humans and what could be done to improve it. However, this is a difficult topic to study because it takes a long time to collect data on human life spans, and many different factors can contribute to mortality. One key distinction is between extrinsic mortality (violence, accidents, infections, etc.) and intrinsic mortality due to genetic mutations and/or aging-related diseases. Shenhar et al. analyzed more than a century’s worth of data from three different Scandinavian twin cohorts and concluded that the current estimates of longevity heritability are much too low (see the Perspective by Bakula and Scheibye-Knudsen). In the late 1800s and early 1900s, when these study cohorts were born, extrinsic causes played a large role in mortality, but once those are excluded, longevity appears to be about 50% heritable, similar to many other traits. —Yevgeniya Nusinovich