Longevity claims are unsubstantiated cases of asserted human longevity. Those asserting lifespans of 110 years or more are referred to as supercentenarians. Many have either no official verification or are backed only by partial evidence. Cases where longevity has been fully verified, according to modern standards of longevity research, are reflected in an established list of supercentenarians based on the work of organizations such as the Gerontology Research Group (GRG) or the Guinness World Records. This list includes claims between 115 years and 130 years.
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Scientific status
Prior to the 19th century, there was insufficient evidence either to demonstrate or to refute centenarian longevity. Even today, no fixed theoretical limit to human longevity is apparent. Studies in the biodemography of human longevity indicate a late-life mortality deceleration law: that death rates level off at advanced ages to a late-life mortality plateau. This implies that there is no fixed upper limit to human longevity, or fixed maximum human lifespan. Researchers in Denmark have found a way to determine when a person was born using radiocarbon dating done on the lens of the eye.
Categorization
In 1955, Guinness World Records began maintaining a list of the verified oldest people. It developed into a list of all supercentenarians whose lifespan had been verified by at least three documents, in a standardized process, according to the norms of modern longevity research. Many unverified cases ("claims" or "traditions") have been controverted by reliable sources. Taking reliable demographic data into account, these unverified cases vary widely in their plausibility.
Problems in documenting
In numerous editions from the 1960s through the 1980s, Guinness stated that
No single subject is more obscured by vanity, deceit, falsehood, and deliberate fraud than the extremes of human longevity.
Despite demographic evidence of the known extremes of modern longevity, stories in otherwise reliable sources still surface regularly, stating that these extremes have been exceeded. Responsible, modern, scientific validation of human longevity requires investigation of records following an individual from birth to the present (or to death); purported longevity far outside the demonstrated records regularly fail such scrutiny.
Actuary Walter G. Bowerman stated that ill-founded longevity assertions originate mainly in remote, underdeveloped regions, among non-literate peoples, with only family testimony available as evidence. This means that people living in areas of the world with historically more comprehensive resources for record-keeping have tended to hold more claims to longevity, regardless of whether or not individuals in other parts of the world have lived longer.
In the transitional period of record-keeping, records tend to exist for the wealthy and upper-middle classes, but are often spotty and nonexistent for the middle classes and the poor. In the United States, birth registration did not begin in Mississippi until 1912 and was not universal until 1933. Hence, in many longevity cases, no actual birth record exists. This type of case is classified by gerontologists as "partially validated".
Proximate records
Since some cases were recorded in a census or in other reliable sources, obtainable evidence may complete full verification.
Late-life records
In another type of case, the only records that exist are late-life documents. Because age inflation often occurs in adulthood (to avoid military service or to apply for a pension early), or because the government may have begun record-keeping during an individual's lifetime, cases unverified by proximate records exist. These unverified cases are less likely to be true (because the records are written later), but are still possible. Longevity narratives were not subjected to rigorous scrutiny until the work of William Thoms in 1873. Thoms proposed the 100th-birthday test: is there evidence to support an individual's claimed age at what would be their centenary birthday? This test does not prove a person's age, but does winnow out typical pension-claim longevity exaggerations and spontaneous claims that a certain relative is over 150.
Reports with complete date of birth
These are standardized lists of people whose lifespans remain unverified by proximate records, including both modern (Guinness-era) and historical cases. Claims missing either (or both) a date of birth/date of death are listed separately. All cases in which an individual's supercentenarian lifespan is not (yet) backed by records sufficient to the standards of modern longevity research are listed as unverified. They may be factually true, even though records do not exist (or have not yet been found), so such lists include these grey-area cases.
Recent
These living supercentenarian cases, in descending order of claimed age, with full birth and review dates, have been updated within the past two years, but have not had their claimed age validated by an independent body such as the Gerontology Research Group or Guinness World Records. Only claims over 115 years but under 130 years are included in the list.
Past
This table contains supercentenarian claims with either a known death date or no confirmation for more than 2 years that they were still alive. Only claims of ages 115–129 are included. They are listed in order of age as of the date of death or date last reported alive.