The traditional Jewish blessing for long life, the title of this article, is not just the stuff of ethnic folklore. The source for the blessing is a verse in Beresheet (6:3) in which Gd decrees that the maximum human lifespan would be 120 years (“man’s days shall be 120 years”). Since everyone presumably wants to live for as long as possible, it has become traditional to wish a friend the maximum number of years – in good health, of course.

Before the 20th century, it was extremely rare for anyone to live for more than 100 years, and absolutely nobody reached the age of 110. In fact, until quite recently, scientific literature cited either
105 or 110 years as the maximum human lifespan. Therefore, on the basis of observation alone, there would never have been any reason to consider the higher figure of 120 years.

The widely circulated anecdotal reports of remote mountain villages in the Caucasus region of Georgia, or in Ecuador, Colombia or Pakistan, where many people supposedly live longer than 120 years, have no basis in fact. Such reports are, of course, very beneficial to the tourism industry, but research shows that they are entirely baseless. Both Russia and Colombia sought to propagate these legends by issuing postage stamps in 1956 to honor their respective longest-lived
citizens. The Colombian stamp depicted a man said to be
167 years old, whereas the Russian stamp was somewhat more modest, claiming only the age of 148 for its most senior citizen. The alleged theory credited the healthy atmosphere of the mountains, the relaxed lifestyle and simple diet – sometimes a particular type of yogurt is mentioned – with enabling these fictitious lifespans.


It was only in the latter part of the 18th century that precise birth records began to be kept on a widespread scale, thus making it possible to reliably establish the age of the oldest human beings. Based on such records, scientists, until recently, accepted the claim that the “oldest person in history” was a Japanese man listed in the 1987 Guinness Book of World Records, Shigechiyo Izumi, who died in 1986 at the age of 120. Sarah Knauss of Pennsylvania, who is said to have been the oldest American ever, died in 1999 at the age of 119 years and 97 days. The oldest verified age for a man is said to have been achieved by Jiroemon Kimura of Japan, who died in 2013 at the age of 116 years and 54 days.

And so for the first time in post-Biblical history, we have authenticated cases of people reaching the age of 120, just as it is written in Beresheet 6:3.

Let us now consider the reverse question. What is the likelihood of a person living beyond 120 years? With improved healthcare for the elderly and the medical miracles constantly unfolding before our eyes, perhaps the day will come when people will live to the age of 130 or 140, or even beyond. Is there any scientific evidence to show that the maximum human life span is limited to 120 years?

Making accurate estimates of the largest possible values of various quantities on the basis of previous experience is a new and active field of statistical studies. For example, it is important to be able to determine how destructive the next earthquake or flood will be, on the basis of the history of earthquakes and floods in the region. This field of statistics, known as extreme value theory, has received renewed impetus through the research work of Professor Richard Smith of the University of North Carolina.

One of the most intriguing applications of extreme value theory is to the question of human longevity, a subject of great interest to biologists and actuaries alike. Such an analysis was recently carried out by Professor Laurens de Haan and his colleagues at Erasmus University in Rotterdam, Holland. Using all the available data on human longevity, Professor de Haan determined that the maximum human lifespan is 119 ± 6 – a result which is clearly consistent with the Biblical reference to 120 years.


Most of us have an unfavorable image of extremely old people. We tend to think of nonagenarians and centenarians (often called “the oldest old”) as physically infirm and mentally debilitated. Thus, the traditional blessing of “may you live to 120” seems insincere. Why should anyone want to live so long only to end up as a burden on his or her children?

Recent studies demonstrate that this unfavorable image has no basis in fact. Professor Thomas Perls, a geriatrician at Harvard Medical School, explains:

The prevailing view of aging as advancing infirmity is wrong. The oldest old are often the most healthy and agile of the senior people in my care… Centenarians, with few exceptions, report that their nineties were essentially problem-free. As nonagenarians, many were employed, physically active, and enjoyed the outdoors. Accumulating evidence indicates that we must revise the common view that advancing age inevitably leads to extreme deterioration.

Similar views are expressed by Professor Richard Suzman of the National Institute of Aging at the NIH (National Institutes of Health), who emphasizes that pessimistic expectations of infirmity for the oldest old are being revised in the light of new studies:

National data show that a surprisingly large percentage of the oldest old require no personal assistance on a daily level, and are also physically robust… Health-service research is revealing that a large percentage of those in old age remain low-cost users of medical services.

Other authorities confirm these views:

New scientific evidence regarding physiological aging shows that we overestimated the age rate of decline for the oldest old in various physiological functions. Recent studies of healthy survivors to advanced ages show that physiological functions decline much more slowly than previously thought. For example, the cardiovascular function of healthy 80-year-olds was found to be similar to that of 30-year-olds.

I would like to add a personal anecdote. In 1984, I had the privilege and pleasure of meeting Charlotte Hughes, then Great Britain’s second-oldest person, who was 111. Mrs. Hughes was physically fit and completely lucid throughout our conversation. She told me that she read the Bible every day. On the occasion of her 110th birthday, she was flown to New York City on a supersonic jet as the personal guest of the mayor. Mrs. Hughes enjoyed life fully until she died in her 114th year.

This optimistic view of the vitality of the oldest old is fully supported by the statistical data on human mortality. Throughout most of life, human mortality increases with age at a steady pace (called the “Gompertz law of mortality”). However, upon reaching the age of the oldest old, the rate of increase in mortality suddenly slows, and then stops altogether. In fact, the data for centenarians show that their mortality rate actually decreases. This means that after the age of 105, the one person in a million still alive has a greater chance of reaching age 106 than an individual aged 104 has of reaching age 105.

Professor Kenneth Manton of the Center for Demographic Studies at
Duke University, an authority on demographic patterns of aging, has reached similar conclusions:

The vital statistics data show very little increase in mortality above age 100… There is an actual decline in mortality above age 104, based upon British population registry data. Similar patterns have been found in the United States, Sweden, and France. 


The conclusion we may draw from these recent scientific findings is that if one is granted the privilege of living an extremely long life, in fulfillment of the traditional blessing, then statistics have shown that it is usually accompanied by good health. Divine favor is not marred by physical or mental infirmities.

Professor Nathan Aviezer is an accomplished author, professor of physics and former chairman of the Physics Department of Bar-Ilan University in Israel. This feature was adapted from an article that appeared in The Jewish World of Wonders.