Life expectancy for the longest-lived populations has been growing more or less linearly since the 1840s.

Up to 50% of all variation in lifespan may be due to genetic factors, indicating a significant but not exclusive role of genetics in determining longevity.

The FOXO3 gene is closely associated with longevity, and particular variants of this gene are found more frequently in individuals aged 90 and above, suggesting a genetic basis for extended lifespan.