Imagine a civilisation resembling our own, except that the "people" there have predetermined lifespans. That is, in the absence of unnatural death (deaths caused by external forces like car accident, gun, fire, water, hunger, thirst etc.), everybody knows exactly how long they are going to live (say 80 years. Note: everybody has identical lifespans. But other organisms than "human" don't have such a characteristic.) since they are born. Let's also assume these people never develop fatal diseases (cancer, HIV etc.), so the only way to die unnaturally is by violent external forces. My question is, in what ways will this civilisation drastically differ from ours?

To name a few, first I think their medical knowledge will remain at a very elementary level since they don't have to deal with tons of fatal diseases that we have to face today. Most likely they will only develop surgical medicine since external wounds are basically the only threats to their life. Second, I think they will have designated places for people to go there and wait for their end in a calm and perhaps even carefree manner. There will be no fear of death since death is SO predictable that they are likely to just view it as a trivial phase of life or simply the gate to their next life cycle. Of course there are many other things I want to explore like how such complete predictability of death will shape their psychological, religional, economical, and political landscapes?

Any compelling story is much welcome. Thanks!


  1. sorry that there's been some confusion on if everybody has the same lifespan: yes, everybody is predetermined to live the same amount of time at birth.

  2. @JBH raised a good point in the comments about whether their organs would "age" or decay during their lifespan, which I didn't think about when writing this post. Let's assume that in this world the elder are also generally less physically agile and less mentally sharp than the younger. You may assume the older have tooth decay at advanced ages, etc. They may also be exposed to the risk of breaking their bones/suffering wounds etc, but they do not suffer a higher risk of death from such stuff than the younger. For example, the probability a wound would kill an elder "person" is the same as the probability the same would would kill a younger "person".

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    $\begingroup$ Welcome to Worldbuilding, Vim! If you have a moment, please take the tour and visit the help center to learn more about the site. You may also find Worldbuilding Meta and The Sandbox (both of which require 5 rep to post on) useful. Here is a meta post on the culture and style of Worldbuilding.SE, just to help you understand our scope and methods, and how we do things here. Have fun! $\endgroup$ – Gryphon Aug 3 '18 at 19:21
  • $\begingroup$ No tooth decay? No cuts and associated infection? No broken bones? No curiosity, just wondering what all the tubes and stuff do? Do the plants and animals enjoy the same protection? or is there veterinary science (not all that disimilar to human medical science). How about blood clots that cause stroke, etc. You'd have fewer pharmaceuticals, but my knee-jerk reaction is that life would be very little different from today. $\endgroup$ – JBH Aug 3 '18 at 19:22
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    $\begingroup$ Keep in mind, everybody dies. All you're doing is removing some of the random chance of a non-statistical death and narrowing the statistics. It wouldn't change religion, politics, our psychology. Nada. Everybody still dies, and basically at the time we all expect to die anyway. $\endgroup$ – JBH Aug 3 '18 at 19:24
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    $\begingroup$ Logan's Run!!! Everyone dies at age (in the book: 21, the movie: 30). $\endgroup$ – RonJohn Aug 3 '18 at 20:06
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    $\begingroup$ Read Lifeline by Robert Heinlein. It is close to an answer to this question. $\endgroup$ – Wildcard Aug 14 '18 at 0:58

Organ donation will be an easier process

Accidents will still happen. And in case you need an organ replacement, you will have available a well-planned list of candidates where you will know exactly when the organs are available.

School could be optional

Would I have the same desire to graduate if I know I will die teenager? Perhaps not. Would I want to be a Doctor if I know I will die in my 3rd semester? Probably not. As Sarah said above, my life decisions may vary a lot because now I know exactly how much time I have alive. And I could plan better my long term decisions.

"Life imprisonment" will have a different meaning.

In case you are selected to go to jail "forever". You will know exactly how many years you will spend there.

People may take more risky decisions

I could enjoy a bungee jump from the Empire State Building, and no problem if I die: Anyway I have only 2 hours of life. Or I could go and commit a crime, knowing there will be no problem with the consecuence because I will be dead a few hours later.

No life insurance as we know it

Life insurance is based on a statistical "random" process. If you know exactly the moment of your death, there is no business at all in there.

Your life span will be needed in your resume

Unless prohibited by law, the company about to contract you will obviously be interested in your life span. And that takes us to this next point:

Short-lived discrimination

People with a short life span may not be required for many jobs just because of that. They will be seggregated to highly-rotational jobs where is less important the development of the person in the company. They could even have problems finding a couple ("Are you going to marry that guy?? Come on!! He will be dead in 6 months!!") or developing standard social attachments ("Are you sure you want him to be the godfather? He will die next year!")

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  • $\begingroup$ Good point about organ donation and the inclination to commit crimes when close to death. $\endgroup$ – Vim Aug 4 '18 at 2:31

I think that a big factor could be if everyone's predetermined lifespans are identical or not.

If, at birth, you know exactly how many days/years you will live, someone who is told they will live 100 years is instantly in a better position than someone who is told they will only live for 7 years. How many years you have to live could be a social status/symbol, with elite few members of society reaching the highest life-spans. Additionally, you could explore the subject of how much time you have vs how you spend your time. Someone with 20 years to live might live life more vibrantly, more fully, than someone who has 100. Someone might pity the 20 year human, when the 20 year human understands life better than anyone else might.

If everyone has the same life span, and is subsequently resistant to disease and such, I would imagine Emergency doctors (to deal with accidents, like a car crash) would be more common than typical physicians, or pathologists.

However, I don't think having a predetermined life span would necessarily erase the need for religion, or fear of death. People might just think that their god sets the lifespan. They might be afraid of what comes after. Some people might be constantly worried about fatal accidents that could cut short their lifespans.

I think the biggest societal change would likely be life-structure. For example, general retirement age is 65. Some people work longer, because, if they will live to be 100, they'll need to work longer to financially support themselves. Additionally, if you told a man he would die at age 50, I bet he'd retire at 40 or 45, and not keep working. I would imagine a set life/death cycle would make for more regulated lifespans/"mile-markers."

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For one thing, the stages of life will be more predictable. On earth, we can give fairly good (maybe stereotypical) descriptions of phases of life like the teen years, early adulthood, midlife crisis, etc, but there's really no stereotypical "pre-death" or "anti-teen" phase because people die at different ages. If everyone in your world dies at 80, I bet there would be very well-known and predictable phases that people go through in the last decade, 2nd to last decade, etc, and there'd be markets and services catering to those phases. For example, maybe it becomes stereotypical that everyone starts writing a book in their 2nd-to-last decade, travels the world in their last decade, etc...

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