“You should respect each other and refrain from disputes; you should not, like oil and water, repel each other.” —Buddha

A few weeks ago, Kane Tanaka celebrated her 117th birthday, thereby extending to five the list of successive oldest verified living people who have done so. According to current expert consensus, only four people had achieved that milestone prior to those five. This adds yet more fuel to various fires that have raged, not least in this journal, concerning the likely future trajectory of maximum human longevity:

Has its rise stagnated? 1–3

Will medical progress eventually bring about its dramatic acceleration?

How thoroughly can, and should, we verify past claims of extreme longevity?

In this special issue, four articles offer a range of new insights into these matters. It is to be hoped that they will take the corresponding debates forward. However, there are reasons to be pessimistic. Not one of the authors of these articles is a credentialed academic specializing in the topic (though one is a highly, and rightly, respected autodidact in the validation of claims of extreme longevity4,5). This is not the result of my choice; a number of invitations to contribute were not even dignified by a response, let alone a positive one. Instead, some of those invitees have chosen to express their views in the media and in popular articles. One might wonder why.

The difficulty here is that the topic combines disciplines that do not often intersect—and that do not draw on particularly similar skills. Scientists like to have as much information as possible before even tentatively drawing conclusions, and they typically work in situations where they can get it: not least, they can repeat an experiment if they doubt its replicability. Historians, on the other hand, work with often very fragmentary data and are not in much control over it, and the past cannot be revisited. The study of extreme longevity is a particularly challenging case because of the high frequency of exaggerated claims, leading to a requirement to develop sophisticated methods of validation based on multiple historical records. And one unfortunate thing that scientific and historical research do have in common is that a number of researchers, not least the most prestigious ones, find it quite difficult to entertain the idea of admitting that they might in the past have been wrong in their conclusions.

The currently accepted longevity world record holder, Jeanne Calment, has been the focus of recent debate in this field, because of Nikolay Zak's reinvestigation of the possibility that her daughter assumed her identity.6 For the record, I remain just as open minded regarding whether this switch occurred as I have been since Zak's work came to my attention in 2018. However, I am decidedly less open minded concerning the quality of the arguments put forth by some of the most respected scientists in the field concerning the motives of Dr. Zak and those who have chosen not to condemn him for his temerity in (as they evidently see it) insulting the honor of Mme Calment, her family, her home town, France, etc. While the accusations that have been leveled at some of us are objectively ludicrous and thus harmless to their targets, they demean the authority and prestige of the accusers—which harms science as a whole. The most extreme example is that of Jean-Marie Robine, one of the original validators of Calment's age, who has gone so far as to express hope that a blood sample taken from her and stored in Paris, which could not only decide the ID-switch question once and for all but could also (if, as he remains sure, no switch occurred) be of immense value for the biological study of extreme longevity, has been destroyed. One does not need much imagination to infer his motives, and to conclude that he knows more than he is letting on. It is not often that words fail me, but I will just say that if that is the attitude for which a researcher wants to be remembered, he is no researcher.