Why do human lifespans vary so much in Middle-earth?

Question

The LotR project's statistics section offers some confusing numbers in regards to human life expectancy. Their figures are based on a survey of all characters for whom the relevant data exists, and are broken down by which era the character lived in (First Age, Second Age, Third Age), as well as Númenórean and "regular" ancestries.

This could be explained by reference to the longevity of Númenóreans and their descendants, but the summary of the data as it appears on Tolkien Gateway's entry on Men confuses things somewhat:

Didn't Numenor exist in the First Age? Wouldn't the figure for First Age lifespans be higher than that for the Third Age?

Or is the surprising data a reflection of the methodology employed by LotR Project?

The life length of Men is perhaps the most complex to interpret. To give a complete picture they have been separated by Age and and into Men of Númenórean blood (including descendants) and regular Men. Since the Númenóreans were blessed with long life their average life length was well beyond 200 years. Their descendants shared the same blessing although the life-length decreased over the years.

This graph shows the average life-span of Hobbits, Dwarves and Men based on characters with known birth and death data.

The study was forced to rely on named characters who were important enough to warrant specifying their dates of birth and death. Tolkien focused on great leaders far more than commoners. Many of the great leaders of Men were Númenóreans or their descendants. This would all add up to data skewed heavily towards Númenóreans and less representative of the general population. However, this bias would be partially corrected by the fact that the great leaders fought lots of wars, and often died in them, long before they would have died of natural causes. Tolkien also wrote that most "good" Númenóreans didn't live as long as they could have — they chose to die at a time they deemed appropriate:

"A good Númenórean died of free will when he felt it be the time to do so".

— Tolkien, Letter 156.

And the figures for "regular men" (i.e., men who are not descended from Númenóreans) — which are based on a somewhat smaller sample size — are also surprisingly high, at almost 90 years. How can this be explained?

Answer 1

No, Númenor did not exist in the First Age; it was created at the beginning of the Second Age as a reward for their aid in the Wars of Wrath:

A land was made for the Edain to dwell in, neither part of Middle-earth nor of Valinor, for it was sundered from either by a wide sea; yet it was nearer to Valinor. It was raised by Ossë out of the depths of the Great Water, and it was established by Aulë and enriched by Yavanna; and the Eldar brought thither flowers and fountains out of Tol Eressëa. That land the Valar called Andor, the Land of Gift; and the Star of Eärendil shone bright in the West as a token that all was made ready, and as a guide over the sea; and Men marvelled to see that silver flame in the paths of the Sun.

... This was the beginning of that people that in the Grey-elven speech are called the Dúnedain: the Númenóreans, Kings among Men. But they did not thus escape from the doom of death that Ilúvatar had set upon all Mankind, and they were mortal still, though their years were long ...

(Silmarillion, "Akallabêth")

Those who came to that land were granted a very long lifespan, particularly in the royal house:

But to Elros, who chose to be a king of Men, still a great span of years was allotted, many times that of the Men of Middle-earth; and all his line, the kings and lords of the royal house, had long life even according to the measure of the Númenóreans. But Elros lived five hundred years, and ruled the Númenóreans four hundred years and ten.

Most of these rulers did not, in fact, die in wars; for most of its existence Númenor was at peace with other peoples, and for most of the rest it was powerful enough that its kings were never threatened in war.

This would explain the lower figure for the First Age. It's also explained by the paucity of data points (there are relatively few Men mentioned in the annals of the First Age, and we frequently don't get enough information to estimate their age at death).

In the Third Age, most humans with birth and death dates recorded were Kings of Gondor and Arnor, or their descendants; these had to an extent the longevity granted to the Kings of Númenor, but to a lesser extent; thus their average age might be expected to fall between the First Age and Second Age figures.

---

Note: Emil Johanssen, who runs the Lord of the Rings Project, states in his section on "Life-length distribution by race":

Men show some interesting characteristics suggesting that there are three different mean ages. One for regular men close to 80 years, one for Númenoreans and their descendants at about 200 years and finally one for the Númenoreans of royal blood close to 400 years. Elros who lived to become 500 years is not included since he is a Half-elf.

This is reflected in the overall figures you mention.

Answer 2

I can't comment on the statistical methods - that was not my best subject in school.

Númenor

Númenor did not exist in the First Age; that land, and the extended lifespan of its inhabitants was a gift to a particular subset of Men, thanking them for their assistance during the War of Wrath:

It is said by the Eldar that Men came into the world in the time of the Shadow of Morgoth, and they fell swiftly under his dominion; for he sent his emissaries among them, and they listened to his evil and cunning words, and they worshipped the Darkness and yet feared it. But there were some that turned from evil and left the lands of their kindred, and wandered ever westward; for they had heard a rumour that in the West there was a light which the Shadow could not dim. The servants of Morgoth pursued them with hatred, and their ways were long and hard; yet they came at last to the lands that look upon the Sea, and they entered Beleriand in the days of the War of the Jewels. The Edain these were named in the Sindarin tongue; and they became friends and allies of the Eldar, and did deeds of great valour in the war against Morgoth.

[...]

To the Fathers of Men of the three faithful houses rich reward also was given. Eönwë came among them and taught them; and they were given wisdom and power and life more enduring than any others of mortal race have possessed. A land was made for the Edain to dwell in, neither part of Middle-earth nor of Valinor, for it was sundered from either by a wide sea; yet it was nearer to Valinor. It was raised by Ossë out of the depths of the Great Water, and it was established by Aulë and enriched by Yavanna; and the Eldar brought thither flowers and fountains out of Tol Eressëa. That land the Valar called Andor, the Land of Gift

^{_{The Silmarillion IV Akallabêth}}

Dying Kings

The question discusses the possibility that the Númenórean Kings may have lived shorter lives (well, shorter than they would have otherwise) thanks to having violent deaths, but this isn't actually the case.

Númenor just wasn't involved in much fighting. The first major military conflict of the Second Age was the War of the Elves and Sauron, which was primarily fought by the Elves and Sauron (wouldn't you know it). The Númenóreans were very infrequently involved in that conflict; they helped to hold the Grey Havens, and utterly routed Sauron's forces in a subsequent battle:

In 1695, when Sauron invaded Eriador, Gil-galad called on Númenor for aid. Then Tar-Minastir the King sent out a great navy; but it was delayed, and did not reach the coasts of Middle-earth until the year 1700. By that time Sauron had mastered all Eriador, save only besieged Imladris, and had reached the line of the River Lhûn. He had summoned more forces which were approaching from the south-east, and were indeed in Enedwaith at the Crossing of Tharbad, which was only lightly held. Gil-galad and the Númenóreans were holding the Lhûn in desperate defence the Grey Havens, when in the very nick of time the great armament of Tar-Minastir came in; and Sauron's host was heavily defeated and driven back. The Númenórean admiral Ciryatur sent part of his ships to make a landing further to the south.

Sauron was driven away south-east after great slaughter at Sarn Ford (the crossing of the Baranduin); and though strengthened by his force at Tharbad he suddenly found a host of the Númenóreans again in his rear, for Ciryatur had put a strong force ashore at the mouth of the Gwathló (Greyflood), "where there was a small Númenórean harbour." [This was Vinyalondë of Tar-Aldarion, afterwards called Lond Daer; see Appendix D. p. 274.] In the Battle of the Gwathló Sauron was routed utterly and he himself only narrowly escaped.

^{_{Unfinished Tales Part 2: The Second Age Chapter IV "The History of Galadriel and Celeborn"}}

And that was pretty much it. Unfinished Tales also has a chapter devoted to the Kings of Númenor, and the only one who died in battle was Ar-Pharazôn, the one who tried to invade Aman.

Unnatural deaths likely increased following this, as the surviving Númenórean established the Kingdoms of Gondor and Arnor, but none of the people who we have confirmed lifespans for. Elendil and his Faithful, the ones who survived the destruction of Númenor, all lived to fight in the Last Alliance, which was the second (and last) major conflict of the Second Age.

The Third Age

This is when these unnatural deaths start coming in, as Isildur and his heirs consolidate their kingdoms and face resistance from the locals.

However, we also have to remember the fading grace of the Valar; the original Númenórean Kings were given a long lifespan, but that started to shorten as they became more and more hostile to the Valar and the Eldar:

In those days the Shadow grew deeper upon Númenor; and the lives of the Kings of the House of Elros waned because of their rebellion, but they hardened their hearts the more against the Valar. And the nineteenth king took the sceptre of his fathers, and he ascended the throne in the name of Adûnakhôr, Lord of the West, forsaking the Elven-tongues and forbidding their use in his hearing.

^{_{The Silmarillion IV Akallabêth}}

This fading wouldn't really stop until Aragorn took the throne. Although the lives of Men in the Third Age was much longer than we would expect from a medieval society, they were still shorter than in the Second Age, but with far fewer bloody and destructive wars than the First Age.

Answer 3

From a statistical standpoint, the method used to determine average lifespans has a bad case of sampling bias.

First, it only uses individuals who were recorded in historical chronicles. This means it's not a measure of life expectancy at birth, but of life expectancy at (more or less) adulthood, once an individual has accomplished enough to "make a name for themselves".

Second, as above, it only includes people who did noteworthy things. This means it's heavily biased towards two groups, both of whom can be expected to have atypical lifespans. The first group is kings and nobles, who (barring death in battle) tend to have longer lifespans than the average population. The second group is people who do great deeds, which tend to involve heroic sacrifices and other non-survivable activities, leading to a shorter-than-average lifespan.

Without an unbiased sample, it's impossible to say what the life expectancy of an ordinary individual was. You can get an idea of the trends by taking a consistent sub-sample (say, "kings who died of old age") and assuming the general life expectancy is subject to the same influences, but the chart doesn't even do that: the closest it comes is with the Númenóreans, and even there, it lumps pre- and post-rebellion individuals together.

Answer 4

There are various Men. Hobbits seem longer lived than the men of Rohan and closer to the Dúnedain at this period late in the Third Age. There is a list in Appendix A of the Rulers of Rohan and they generally lived into their seventies. Two exceptions were Aldor the Old and Brytta who were 101 and 90 respectively. Also late in the 3rd Age, meaning after 2000 T.A., the Chieftains in the North generally lived between 155-160 years. Bilbo and Old Took among the Hobbits reached 130 years of age. Among the Stewards this only happened 3 times after 2000 T.A. and the same with the Princes of Dol Amroth. In Appendix C you can check some of the charts on the Hobbits. Take for instance some of the people in Frodo's tree. There's Largo, Fosco, Dora, and Dudo who lived for 92, 96, 104, and 98 years respectively. Some other Hobbits are Bungo, Belba, Longo, Linda, Asphodel, Hobson, Isumbra lll, and the Gaffer lived to 80, 100, 90, 101, 99, 99, 93, and 102 respectively.

From the beginning to the middle of the Third Age the Dúnedain royalty lived from the mid to early 200s except for the last two kings of Gondor (160 & 120 years respectively). In the North only the first 16 kings lived over 200 years and the rest lived from the mid to late 100s, with the Chiefs generally living in the mid 100s, 155-160 years. The Stewards and Princes who were nobles lived from 100-150 years, there was one who lived to 93 and a few 98s and 99s, 6 in all.

In Númenor the royal line generally lived into their late 300s until the shadow fell on their hearts and there was a significantly fast decline in their longevity. From Tar-Atanamir the 13th King to Tar-Vanimeldë the 3rd ruling Queen and 16th ruler went from 421 years to 360 years. Then 330, 309, 281, 253, 235 for the next 5 rulers. The father of the last ruler did not even live to be 200. From Atanamir to Ar-Zimrathôn the lifespan in the ruling house dropped nearly 170 years. This decline was much slower in their cousins in Andúnië. Elendil who came from these Lords died in combat against Sauron at the end of the 2nd Age when he was 322. There was quite a difference in life expectancy for the Faithful whose leaders were the Lords of Andúnië and the Kings Men whose leaders were the royal line.

I would think that maybe the Men of Darkness, those whose lifestyle and healing skills were not as good as the Middle-men, may have been shorter lived than the Rohirrim, who had as Faramir said, "grown in some way more like to us, enhanced in arts and gentleness" [The Two Towers; "The Window on the West"]. This appears similar to when the Edain first came west into Beleriand and their lifespans had a bit of a boost, but this appears to have been due to what they learned from the Elves.

The years of the Edain were lengthened, according to the reckoning of Men, after their coming to Beleriand...the Edain of old learned swiftly of the Eldar all such art and knowledge as they could receive, and their sons increased in wisdom and skill, until they far surpassed all others of Mankind

[The Silmarillion; "Of the coming of Men into the West"]

Beor who was called the Old lived until he was 93.