New Study Finds Genetics Account for Half of Human Lifespan Differences

Tue, 14 Apr 2026 13:21:00 +0200

A new study from the Weizmann Institute of Science challenges decades of assumptions about human longevity, revealing that genetics may play a far larger role in determining lifespan than previously believed. For many years, researchers estimated that inherited factors accounted for only about 20 to 25 percent of the differences in lifespan, with some studies suggesting even less. However, this new study, published in Science, found that genetic influences could explain roughly half of the variation in how long people live. The research team, led by Ben Shenhar and Professor Uri Alon, analyzed massive twin datasets from Sweden and Denmark, including both twins raised together and those separated early in life. This approach enabled them to better distinguish between inherited and environmental effects on longevity. The study further refined its results by using advanced mathematical models and simulations to filter out “extrinsic mortality” — deaths caused by accidents, infections, or