The heritability of intrinsic human lifespan is approximately 50% when confounding factors are taken into account. A study published in the journal Science (Volume 391, Number 6784, Pages 504-510, January 2026) analyzes this data after adjusting for environmental and other variables. Previous estimates have been lower, such as 25–30% for maximum life expectancy, due to insufficient treatment of confounding factors[1]. The main finding confirms the importance of genetics in determining the natural length of life without external interventions. Research highlights that genetic factors explain half of the variability in intrinsic lifespan. These results are based on data on family ties and population statistics adjusted for environmental influences.