# Late-life mortality deceleration (mortality plateau)

The mortality plateau (late-life mortality deceleration) is a striking observation. Past about age 105, your risk of dying stops climbing exponentially. Instead it flattens to a roughly constant rate. Normally, death risk accelerates with age (the Gompertz law). But Barbi et al. (2018, Science) studied every Italian aged 105+ between 2009 and 2015, all 3,836 of them. They found an essentially flat curve. The annual death probability settled around 47 to 48%. They concluded that limits to human lifespan may be more elastic than thought. The leading explanation is population heterogeneity. At extreme ages, the survivors are mostly the biologically toughest people. So the plateau may come from selective survival, not a real slowdown of cellular aging. (Vaupel and colleagues formalized this 'frailty selection' effect.) The finding is contested. Gavrilov and Gavrilova (2019, PLOS Biology) pushed back. Their simulations showed that age-reporting errors past 105 can fake a plateau. That happens even in perfectly Gompertzian data. And Dang et al. (2023, Demographic Research) used French data followed from 105. They found no plateau at all. Death rates kept rising. The lesson: extreme-age mortality is very sensitive to data quality, country, and cohort.

## Sources

- Barbi E, Lagona F, Marsili M, Vaupel JW, Wachter KW. (2018). The plateau of human mortality: Demography of longevity pioneers. Science. https://doi.org/10.1126/science.aat3119
- Gavrilov LA, Gavrilova NS. (2019). Late-life mortality is underestimated because of data errors. PLOS Biology. https://doi.org/10.1371/journal.pbio.3000148
- Dang LHK, Camarda CG, Meslé F, Ouellette N, Robine JM, Vallin J. (2023). The question of the human mortality plateau: Contrasting insights by longevity pioneers. Demographic Research. https://doi.org/10.4054/demres.2023.48.11

---

_Canonical: https://longevity-switzerland.com/en/glossary/mortality-plateau · Part of Longevity Cities · Updated 2026-06-22_