A Bayesian Assessment of the Longevity of Jeanne Calment.

Mme Calment died in 1997 at the reputed age of 122 years, the longest validated life span of all time. Recently it has been suggested that in fact Mme Calment was not Jeanne Calment born in 1875 as believed, but rather her daughter Yvonne born in 1898. She could have swapped identity on her mother's death in 1934. In this study, the most reliable evidence is evaluated and competing versions of hypothetical scenarios are compared. No information is completely certain so only probabilities are considered. Methods of Bayesian inference are used to assess the probability of correctness for each scenario. It is not possible to form a definitive conclusion with the evidence currently available, but we believe that the outcome reinforces earlier suggestions that Mme Calment's age validation is unsafe in the light of recent evidence and should be reviewed. Indicators from DNA analysis that could reliably resolve the question of whether or not an identity switch took place are provided. The methods of Bayesian inference used here could be applied to other longevity validations to improve the validation process for longevity.

Comment on 'Naked mole-rat mortality rates defy Gompertzian laws by not increasing with age'.

Ruby et al. recently analyzed historical lifespan data on more than 3200 naked mole-rats, collected over a total observation period of about 38 years (Ruby et al., 2018). They report that mortality hazards do not seem to increase across the full range of their so-far-observed lifespan, and conclude that this defiance of Gompertz's law 'uniquely identifies the naked mole-rat as a non-aging mammal'. Here, we explain why we believe this conclusion is premature.

Evidence That Jeanne Calment Died in 1934-Not 1997.

I present a body of data that, I argue, cumulatively casts serious doubt on the validity of Jeanne Calment's accepted world record of human life span. First, I assess the plausibility of the record based on the life spans of other centenarians in the International Database of Longevity (IDL) and critique some arguments put forward previously in support of that plausibility, including the longevity of Calment's ancestors. Second, I review the literature dedicated to Calment and discuss multiple contradictions in her interviews, biographies, photos, and documents. I argue that the evidence from these sources motivates renewed consideration of the previously rejected hypothesis that Jeanne's daughter Yvonne acquired her mother's identity after her death to avoid financial problems and that Jeanne Calment's death was reported as Yvonne's death in 1934. Finally I discuss the importance of reconsidering the principles of validation, due to the possibility of similar problems regarding other exceptionally long-lived people and the mistaken inferences that researchers may draw from flawed datasets. The phenomenon of Jeanne Calment may prove to be an instructive example of the uncertainty of seemingly well-established facts.