So, my alien species, called the Collectors, have just abducted 72 humans from Earth, to become the newest collection in their ever growing zoo.

These 72 humans are all from every background, race and ethnicity. There are 36 guys, 36 girls, and inside the enclosure is everything the humans need. For human mental health reasons, what would be the optimal size?

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    $\begingroup$ This is very dependent on how much space is used by such things as bathing facilities, food preparation (and storage - how do they get food) and whether the psychological state of individuals - some people can get by with less space than others and some people are simply anti-social while some are too social for average comfort. There's no simple unique answer to this. $\endgroup$ – StephenG Jun 29 '18 at 6:25
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    $\begingroup$ don't forget that mixing genders together tends to lead to breeding so 72 soon will soon be A LOT MORE ;) $\endgroup$ – Creed Arcon Jun 29 '18 at 7:48
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    $\begingroup$ Do they vary in ages, too? Are there children? Teenagers? Middle-aged? Elderly? Families? Will the abductors be providing human dentistry and medical care within the enclosure or elsewhere? Does 'everything the humans need' include water closets (flush toilets) or chamberpots? Is the food bland human-chow or ingredients the imprisoned can cook? $\endgroup$ – user535733 Jun 29 '18 at 8:08
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    $\begingroup$ according to 50/500 rule, this group will become inbred within a few generations, unless excessive measures are taken to prevent this. $\endgroup$ – Trish Jun 29 '18 at 9:28
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    $\begingroup$ If it just size calculation for storage at night, stackable coffin are enought. $\endgroup$ – Drag and Drop Jun 29 '18 at 13:19

So, I actually had similar question, so I decided to google it.

Because humans look like chimpanzees[citation needed], I decided to google, how much space do you need for an ape.

Space Requirements for caged non-human primates in the United States provides great source for common sense ruling:

  • Baboons (15-25kg): 1.5 m2 in Europe, 0.75 m2 in USA

Or, another great source could be prison space requirements:

The CPT’s minimum standard for personal living space in prison establishments is:

  • 6m² of living space for a single-occupancy cell + sanitary facility
  • 4m² of living space per prisoner in a multiple-occupancy cell - fully-partitioned sanitary facility
  • at least 2m between the walls of the cell
  • at least 2.5m between the floor and the ceiling of the cell

So if you decide to keep your humans separate, you need 72*6 = 432 m² just for living spaces. As common sense, I would double that for shared rooms and some place to stretch and go for 800 square m.

(If someone is willing to translate the units to non-SI units, please feel free to edit this answer)

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    $\begingroup$ While these figures are helpful, i'm not sure this qualifies This is the place for cells for prisoners. While knowing them only from movies, afaik, prisons tend o have yards so the inmates can get a bit of open space once a day. And ven with that, i'm not sure the "mental health" criterion from OP is fully met. $\endgroup$ – Burki Jun 29 '18 at 8:12
  • $\begingroup$ @Burki I actually agree, but still think that it can provide you good common sense minimal requirements, so you know at least roughly what do you need to do $\endgroup$ – Pavel Janicek Jun 29 '18 at 8:37
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    $\begingroup$ +1 I don't expect anybody wanting to put humans in a zoo being more concerned about space than prison planers. $\endgroup$ – Pere Jun 29 '18 at 12:17
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    $\begingroup$ @Pere It depends on what they want the zoo to be. "Traditional" zoos certainly put animals in conditions more like a prison; and like a prison, the result was atypical behaviour from the animals. The focus was on seeing the animal, not on seeing how it behaved. Modern zoos though are more concerned with giving the animal similar living conditions to the outside world, so that they can do research on animals in captivity which is applicable to the real world. It seems likely that the OP's Collectors would be the same. $\endgroup$ – Graham Jun 29 '18 at 13:12

The answer depends on way too many factors.

Coming from different cultures and places, each individual's necessities will be forcefully different, not to mention that they all need to have their own rooms, or Cabin Fever will set in and your net result will be a bunch of psychopaths intent on killing each other (just as a reminder: being captured and brought in a zoo may be quite the unsettling experience).

EDIT: So, the best I can suggest is that they are placed in a resort-like structure, with a room equipped for each one's needs, and full liberty to walk around. To the benefit of the zoo visitors, the hotel will be either filled to the roof with cameras for a complete 3D real time visual of the prisoners' interactions and daily life, or made of glass -sure, the prisoners will be at first be embarrassed, dazed, upset, but in the end they'll get used to it. We are humans, getting used to stuff and situations is our thing

EDIT II: Advantage of living in this kind of resort offers at least for its inhabitants the possibility to form a microsociety with its rules and habits. A surrogate society, sure, but a society. With time, some of its members will probably try and take their own lives, or some will probably go postal -it happens with being prisoners, but if the experience with our own prisons teaches us something, Humans are resilient. We can adapt to places intended for the harshest punishments and form solid groups that will keep in touch even after they leave.

And we are talking, here about a very gilded cage. Daily fresh food, entertainment, interaction, and as only rule: do not harm each other or yourselves. Visitors get to watch a growing reality/soap for their amusement, the prisoners are treated, in proportion, far better than we do treat our animals in our bioparks

  • $\begingroup$ if you make your hotels external walls from 1-way glass, they could be unaware of being observed $\endgroup$ – ErosRising Jun 29 '18 at 11:38
  • $\begingroup$ Yup, that too. Although i'd find it...creepy to have a reflection of myself around 24/7 $\endgroup$ – Valerio Pastore Jun 29 '18 at 11:41
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    $\begingroup$ Perhaps these collectors have the technology to have the backside not reflective; or project a different image. They look out the window and see something earth-like, when in fact the "guests" are peering in at them. $\endgroup$ – ErosRising Jun 29 '18 at 11:56
  • $\begingroup$ You aren't given your exhibits any outdoor space? Remember that many of them will need regular exposure to full-spectrum natural light for optimal well-being... $\endgroup$ – user3067860 Jun 29 '18 at 16:32
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    $\begingroup$ Downvoted this (and all similar answers) because the OP is asking about mental health. Most humans confined to such a small space for a long period will develop mental health issues. Except perhaps agoraphobes, but they already have mental health issues :-) $\endgroup$ – jamesqf Jun 29 '18 at 17:19

Having lived in Tokyo and London, I can tell you it's pretty easy to get used to live in small private spaces, something like a 17 square meter house shared in two. And you can get even lower.

And being in a zoo means you don't have to worry about storing stuff, as the zoo will take care of it.

Just ensure that the "public space" is wide enough to allow social interaction: if you can't throw a party at home because 3 people would cramp the place, at least have a pub where you can meet with friends.

  • $\begingroup$ With 17m² about a quarter should be used up just for sleeping space. Does this include a kitchen and a bathroom? I suppose you could cram both of these into 2m×2m areas if you have tiny stackable versions of everything, but otherwise I don't see how it'd be possible other than using public facilities. $\endgroup$ – Cubic Jun 29 '18 at 12:23
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    $\begingroup$ @Cubic, 17 square meter with all in (toilet, shower, kitchen). but 1 folding bed $\endgroup$ – L.Dutch - Reinstate Monica Jun 29 '18 at 12:41
  • $\begingroup$ I would imagine that you didn't live in that small space 24/7, 365 days per year, for years on end. Even when I lived near London, I could get out into the town, and go hiking & biking in places like the Ridgeway or the Lake District on weekends. $\endgroup$ – jamesqf Jun 29 '18 at 17:23
  • $\begingroup$ @jamesqf, that's why I made a distinction between private and public space. $\endgroup$ – L.Dutch - Reinstate Monica Jun 29 '18 at 17:47
  • $\begingroup$ @L.Dutch: But public/private space is not relevant to the OP's question. It asks how much space is needed for the humans as a group, to avoid mental health problems. Given a sufficiently large enclosure, the humans might of course decide to partition some of it into private space. $\endgroup$ – jamesqf Jun 29 '18 at 20:17

What size of enclosure would be best for a human colony of 72 individuals?

Depends on where you draw the line! Do you want them to live in an authentic environment from our age or the past? Also what is a zoo to them? Because if they define Zoo the same way we do, then these humans would have to be on display! So they wouldn't be very intimate!

What do you want the level of interaction to be? Do they stand in a position and do nothing? Or are they doing things?

The size could vary from 5 m2 for a person to 2 km2 for a person!

  • $\begingroup$ As of now, this seems more like a long comment than an answer. Please use the comment section to ask for clarification about the question. $\endgroup$ – Orphevs Jun 29 '18 at 17:46

I'll try my best to answer this but first just want to point out that 72 people is not enough for coming from every background, race and ethnicity, it would be enough to represent every language, culture etc. to give you an example of this, would anyone here care to say that a New Yorker is the Same as Texan? anyone? because they are both American, and therefore much more similar than say an American to a Greek. hell an American is closer to a Canadian than a Greek, and yet if i suggested they were i'm pretty sure it would anger a lot of people. because although both american they're mannerisms are different.

it would make more sense from a cultural perspective to have a subset or breed of humans the same as we have with penguins etc. South-African, Rock-Hopper, Emperor, King etc. they are all penguins but they either look or act different enough to be a different breed. same with pigeons, dogs, etc. so you'd probably have the New York exhibit, the Texan exhibit and the Greek exhibit, and so on, with a set of human abductees in each, both male and female, and enough that a breeding program could be setup to maintain the Zoo's numbers.

it moves nicely into my next point... cultural differences. anyone who lives and is happy in a city, is generally happier living in a smaller space than those from the country, but oddly, they often prefer that space to be more private, than those in the country who tend to while maybe not prefer but will except less private personal space (rampant generalization there but in my experience it tends to hold true)

Now that's out of the way...


but as a rule, most people on earth will happily get by with a couple of square metre bedroom, nothing more, so long as its got enough space for a bed, they're happy. its functional not a hangout space. now i'm sure most people here will disagree but think about it, most of the planet live in China, India etc. Western culture populations which tends to treat a bedroom as a place to stay in rather than just sleep, is very small compared to the population of the rest of the world. US is 300 mil, uk only 70 mil, china over 1 billion!

This is where the "breeds" of humans would come into it to rectify this issue

again i digress, so a few square metres bedroom, enough for a bedroom, set of drawers, maybe a bedside table... standard single bed is 1 metre, by 2 metres roughly so probably about 4-6 square metres bed across the back, 2 metres by 2 or three is plentiful (for most of earth at least), each, so for your numbers 76 rooms with at 4 square metres absolute minimum each.

Communal Area

For food and socializing, a 12m x 6m (40ft x 20ft) Marquee will have room for 8 tables of 10 guests, 80 in total, make it a little bit bigger to make socializing better, if all these useless humans do is sit around and eat then the alien public aren't going to pay to see that again and again. which makes the exhibit not worth doing. so call is 12m by 10m,

Wash and Toilet Facilities...

1m x 1m for each stall is about average, so enough for a staggered use for showers, you'd want about 8 showers, and about 8 toilets, plus basins etc, so about 6m x 10m would be more than enough, and remember when people go to the zoo often its the small habits like cleaning and eating that people go "look its doing something."


So put all that together and for the numbers you've given and for a fairly bland and uninteresting Zoo. you'd have roughly 484 square metres give or take areas where the aliens would install walkways through the exhibits to get a closer look at the animals as is common with zoos and aquariums here on earth.

of course if you started adding farmland so "here you can see the how these primative creatures gather food" and a gym "so you see here how the males do there best to impress the very unimpressed females", or even a figh... a club i'm not allowed to talk about... to show off the combat skills.

Edit: Mental Health

This is another thing that changes drastically from culture to culture, but often socializing is a more sure fire way to improve/maintain good mental health and environmental factors, this is often more important when it comes to members of the opposite sex. Prisons are an example of if you place people who all tend to be annoyed in some way in close quarters that these general rules don't apply, prisoners often need more space than "free" people because without room to distance themselves when needed, there tends to be riots.

  • $\begingroup$ Penguin species are significantly more diverse than humans. Unlike humans, they are not merely separated by distance, culture and exaggerations of different trait. And prisons are not unusual in the need for separation - socialising is one thing, but there are few humans who thrive being crammed together with large groups of other people at all times. $\endgroup$ – Cubic Jun 29 '18 at 12:27
  • $\begingroup$ i merely used Penquins as an example, i'm aware that its not just size and characteristics, Dogs would have been a better example, still no tthe same as humans but better, but i'd already written about penguins and decided to just keep it. and prisons are unusual when it comes to the type of people that are kept in them. Prisoner are far more likely to riot violently that civilians that are kept confined, its not to say that both don't suffer the same mental health issues, but from a prison perspective the extra space is to reduce risk of riot not just improve mental health $\endgroup$ – Blade Wraith Jun 29 '18 at 13:15

Boats are probably a solid base-line source of reference on this.

Cruise ships come in a wide variety of sizes, and are designed to provide bare accommodations for human beings from a wide variety of origins for an extended period of time. Here is a good example, space for 62 passengers and crew, which should be pretty close to your 72 humans.

That vessel is approximately 120ft stem to stern, and around a quarter as wide as it is long. with three decks, and includes a dining area, lounge, and sun deck, which gives you social spaces and exercise area.

So, somewhere in the neighborhood of 120*30*3 == 10,800 sq ft.

We're doing a lot of rounding up there from our source material, as a boat is not a perfect rectangle, not all decks are the same size, etc, but I think this is appropriate as we're accounting for a slightly larger area to reflect the more permanent nature of the accommodations.

  • $\begingroup$ Few people expect to spend their lives on a cruise ship. To take an extreme case, even nuclear submarine crews - who go through considerable testing to select those few who can tolerate such conditions - are rotated every couple of months. $\endgroup$ – jamesqf Jun 30 '18 at 17:26

First and foremost - food. I'm assuming the aliens can provide enough water, interim food, and electricity, but that the humans will eventually need to grow their own food.

Assuming the Collectors are intelligent enough to abduct some farming equipment and some seed stock, humans can easily support themselves by farming 2 acres of land each, with four growing seasons (made easier if this is an artifcial environment with no cold season). This figure decreases if community farming is set up, but for this purpose I'll assume you need an even 150 acres of land to allow for breeding/population expansion.

Second, living quarters. If we take the prison requirements from Pavek's answer, and add a little extra, we can have 9 blocks of 8 single occupancy cells. Each cell measuring 8m². Each block of cells enclosing a sanitary facility measuring 12m², with four 4mx2m cubicles on opposite walls (shower and toilet cubicles are the same thing. Waste goes down the same hole!) So each block of cells measures a total space of ~30m² when wall space and corridors are accounted for. Residents will need a communal area for eating/socialising. Lets add another 30m² room to the centre of the 9- block complex, bringing the total living space requirements for your colony to ~300m². This is not even taking into account the idea of multiple floors, so this part is really down to what you decide the Collectors will build for the humans.

Human are also going to need something to do. Not everyone will be working the land at once in a community setting. Various recreational activities will take up space. Sports courts, running tracks and swimming pools, as I assume the Collectors will want to show off our greatest assets (these aliens can move quickly on land AND in water?!) will likely take up most of your space requirements.

This can't all be bunched together either, you need paths, roads(?), open areas like parks(?) if your Collectors are nice.

In total, my estimate for a functioning human safari park with farmland, accommodation, and that shows off the best traits of human evolution, you would need around 1000m² of space.

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    $\begingroup$ "but that the humans will eventually need to grow their own food" Why though? If this is supposed to work like a zoo some nutrition would presumably be provided. You don't expect a caged lion to hunt, so why would you expect a caged human to farm? $\endgroup$ – Cubic Jun 29 '18 at 12:30
  • $\begingroup$ Dunno mate, not my story. I've tried to cover as much as possible as the question isn't very specific :) $\endgroup$ – Korthalion Jun 29 '18 at 12:33
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    $\begingroup$ @Cubic Except you do, or at least an approximation. Whilst they won't give the animals something to chase and kill themselves, they stash the meat around the enclosure, including in hard-to-reach places. The idea is to set up a challenge for the animals which is comparable to hunting, as well as preventing the animals from simply seeing humans as a magic food source. Of course most "free-range" humans these days don't farm! but the Collectors could just as well emulate the modern world by setting them work tasks which earn credits in a "store". $\endgroup$ – Graham Jun 29 '18 at 14:07
  • $\begingroup$ As well, humans have a need to work, they need a purpose. Keeping humans together with nothing to do would be the worst thing you could do in terms of mental health! $\endgroup$ – Korthalion Jun 29 '18 at 14:28
  • $\begingroup$ Now I'm envisioning these people using their excessive spare time plotting and overthrowing this world (remember, humans are remarkably fierce) and putting these creatures in the zoo. $\endgroup$ – Hosch250 Jun 29 '18 at 15:14

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