Full transcript
0:00Eight mice were placed inside a perfect
0:02world. Four males, four females. They
0:04had unlimited food and unlimited water.
0:06There were no diseases or predators,
0:08absolutely no threats of any kind. Five
0:10years later, every single one of them
0:12was dead, and not a single death was
0:14caused by anything a vet could have
0:16diagnosed. This is Universe 25, the most
0:19disturbing experiment ever run on a
0:21society. In 1968, an American scientist
0:23named John Calhoun built something he
0:25called a paradise for mice. Soft nesting
0:28material in every corner, the
0:30temperature held perfectly stable, the
0:32cages cleaned by hand on a schedule.
0:34They were the healthiest specimens from
0:36the breeding colony of the National
0:37Institutes of Health. Calhoun was an
0:39ethologist. He had spent his entire
0:41career obsessed with one specific
0:42question. What happens to a society when
0:45nothing is hard anymore? He had been
0:46chasing the answer for two decades by
0:48the time he reached this experiment. He
0:50had built earlier versions in a
0:52quarter-acre forest in Maryland, in barn
0:54enclosures, and in laboratory rooms, 24
0:56of them, one after another. Each one a
0:58slightly different paradise for rats or
1:00mice with no scarcity, no predators, and
1:03no escape. In every single one of them,
1:05he had seen the same pattern. The
1:07population would explode, violence would
1:09spike, mating would distort into
1:11something twisted and hyperactive, then
1:13collapse into apathy, and the colony
1:15would die. He had documented the pattern
1:1724 times. The 25th was meant to be the
1:20perfect one, the clean experiment, the
1:22final answer that nobody could argue
1:24with. He set it up inside a federal
1:26research lab in Maryland, a 9-ft square
1:28enclosure with apartments stacked along
1:30every wall, reached by mesh tunnels
1:32running floor to ceiling. Calhoun called
1:34them walk-up apartments. Each one was
1:37fed by hoppers that never ran empty and
1:39water bottles that never ran dry. He
1:41calculated the space could comfortably
1:42support around 3,800
1:45mice. It would never come close to that
1:47number. On day one, he placed his eight
1:49founders inside and shut the lid. For
1:51the first 104 days, almost nothing
1:53happened. The mice explored, learned the
1:55geography, and worked out who slept
1:57where. Then the first litters were born
1:59and the population began to double every
2:0155 days twice as many mice as before. By
2:04day 315, more than 600 animals were
2:07living inside. They climbed over each
2:09other on the ramps, slept in piles, and
2:11jostled for nesting space at the tops of
2:13the apartments. This is the moment
2:15everything began to come apart. In a
2:17normal mouse colony, when the population
2:19grows past what the territory can
2:20absorb, the surplus mice leave. They
2:23emigrate. They find new ground somewhere
2:25else. Inside Universe 25, there was no
2:28new ground. The young males with nowhere
2:30to go and no role to fill began drifting
2:33into the center of the enclosure. They
2:34formed listless pools of bodies. Calhoun
2:37would stand above the pen for hours
2:39watching them do nothing. They had no
2:41fights to win, no females to court,
2:43nothing to defend. They were healthy,
2:45well-fed, and they had absolutely
2:47nothing to do. When one of them was
2:49attacked by another mouse, he would not
2:51fight back. He would lie there and
2:53absorb the damage, then stand up, walk a
2:55few feet, and lie down again. But not
2:57every male went quiet. A second group
2:59formed at the same time on the opposite
3:01end of the spectrum. They were frantic
3:03and indiscriminate. They moved through
3:05the enclosure faster than any other
3:06mice. They forced themselves into nests
3:09other males were trying to defend. They
3:11skipped the courtship rituals every
3:13other mouse still followed. They refused
3:15to be deterred even by violence from
3:17dominant males. And in the worst pockets
3:19of the colony, behaviors began to appear
3:21that no functioning mouse society had
3:24ever produced. responded with their own
3:26retreat. The ones who could not find a
3:28place in the social order climbed to the
3:30highest apartments and lived alone. They
3:32stopped interacting with males. They
3:34stopped reproducing. Calhoun also
3:36noticed something he called the
3:37behavioral sink. Even when food was
3:40equally available everywhere, the mice
3:42began crowding compulsively around a few
3:44specific feeders. They would not eat
3:46alone. The presence of other mice had
3:47become so wired into their feeding
3:49instinct that an empty feeder, no matter
3:51how full, was useless to them. The
3:53crowding got worse and worse around a
3:55handful of stations while the rest of
3:57the enclosure sat almost untouched. Then
3:59the mothers who were still trying to
4:00raise pups began to fail in a much
4:02darker way. Defending a nest in that
4:04environment took constant work. The
4:06males who had originally claimed
4:08territory grew exhausted from patrolling
4:10and stopped protecting their families.
4:11The mothers had to defend the nest
4:13themselves while still nursing. They
4:14turned on their own young. They
4:16abandoned them in scattered places
4:17around the enclosure. Some forgot which
4:19pups belonged to them at all. Others
4:21stopped recognizing them as theirs
4:22entirely. And in the worst stretches,
4:24mothers began eating their own
4:26offspring. In some sections of the
4:27colony, fewer than one in 20 newborn
4:30mice survived to weaning. Calhoun would
4:32write later that by this point the
4:34social fabric of the colony was
4:35effectively dead. The bodies were still
4:37alive. The structure that held them
4:39together as a species was not. The pups
4:41that did survive were raised by mothers
4:43who barely cared whether they lived.
4:44They had no model of what a functioning
4:47life inside this place looked like. And
4:49when they grew up, they behaved like
4:51nothing Calhoun had ever seen. The males
4:53of this generation never fought. They
4:55never tried to mate. They never engaged
4:57in any social activity at all. They ate,
4:59they slept, and they groomed themselves
5:01obsessively. Their fur stayed perfect
5:04because they never got into a single
5:05fight. They moved through the colony as
5:07if no other mouse existed in it. Calhoun
5:09named them the beautiful ones. They
5:11looked, externally, like the healthiest
5:13mice in the entire colony. They were
5:15also, functionally, dead. They never
5:18tried to reproduce. They could not
5:20socialize. Their nervous systems had
5:22developed inside a world where every
5:24social role was already filled by
5:26someone else. And they had simply opted
5:28out of the species. On day 560, the
5:31population peaked at 2,200 mice. It
5:34would never go higher. The last
5:36successful conception inside Universe 25
5:38happened on day 920. After that, no new
5:41mice were born. The colony continued to
5:44age. The beautiful ones kept grooming
5:45themselves. The secluded females stayed
5:48in their high apartments. Violence
5:50carried on in pockets with no purpose
5:52left to it. And one by one the mice died
5:54of old age with no replacements coming
5:56up behind them. On May 23rd, 1973, the
6:00last mouse in Universe 25 died 4 years
6:03and 10 months after Calhoun shut the
6:05lid. He wrote that the mice had died two
6:07deaths. The first was the death of the
6:09spirit. The second was the death of the
6:11body. The first one happened years
6:12before the second. When his paper came
6:14out, the world ran with the obvious
6:16reading. Comfort kills. Abundance kills.
6:19A life with no struggle is a life that
6:21destroys itself. The image of the
6:23beautiful ones, perfect looking and
6:25quietly extinct, became one of the most
6:27cited metaphors of the late 20th
6:29century. Urbanists pointed to it.
6:31Religious leaders. Politicians on every
6:33side of every issue. Anyone who wanted
6:36to warn about the decay of modern life
6:38found something in those mice they could
6:39use. But that reading was not what
6:41Calhoun actually said. His real
6:43conclusion was sitting there in the
6:44paper, in his own words. For an animal
6:46as complex as a human being, he wrote,
6:49"a similar collapse was not just
6:51possible, it was logical. If the number
6:53of individuals capable of filling
6:55meaningful roles greatly exceeds the
6:57number of roles available, only violence
6:59and disruption can follow." The killer
7:01wasn't comfort, it was the disappearance
7:04of meaningful roles. When the population
7:06grew faster than the supply of
7:07meaningful roles the colony could offer,
7:09the mice with no place stopped
7:11functioning. The fighters had no one to
7:13fight. The mothers
7:15nests that no one helped them keep. The
7:17young grew up with nothing they were
7:19expected to inherit. The structure that
7:21gave each individual mouse a reason to
7:23participate in the species evaporated.
7:25The food never ran out. The water never
7:27ran out. What ran out was something
7:29nobody had thought to put in the
7:31paradise to begin with. Comfort didn't
7:33kill them. It just removed the friction
7:35that made being alive feel like
7:36something. And here is the part almost
7:38nobody quotes. Calhoun himself was not a
7:41doomer. He spent the rest of his career
7:43not predicting the collapse, but trying
7:45to prevent it. He kept building new
7:46universes. He kept changing the
7:48variables. He was looking for the single
7:50thing he could put back into a paradise
7:52that would let it keep working. He
7:53believed it could be done. [music] He
7:55believed humans could choose differently
7:57than the mice did. He wrote that as
7:59physical space contracts, the only way
8:01forward is to extend ourselves into
8:03conceptual space, into ideas, into
8:05networks, into the work of building
8:07roles that did not exist before. He
8:09called it ideational generativity, a
8:11long phrase for a simple idea. The way
8:13out is to keep making new reasons to be
8:16here. But the experiment is still
8:17sitting there in the data, a perfectly
8:19designed paradise, eight mice, five
8:22years, a complete extinction, and a
8:23cause of death no toxicology report
8:26would ever be able to name. The mice
8:28didn't have a choice. We still do. What
8:30happens next is on us.