The Strangest Experiment Ever | The Acali Raft Experiment | True Story

Added: 2026-06-03

[00:00:01]In 1973, a scientist loaded six women and five men onto a raft and pushed them into the Atlantic Ocean. No motor, no privacy, no way off.

[00:00:12]He had chosen them carefully. Different nationalities, different backgrounds, deliberately mixed. He had given the women power over the men. He had picked storm season on purpose. He had removed every distraction so they would have nothing to do but interact with each other.

[00:00:27]He had a theory about what humans do under pressure, and he had built the perfect machine to prove it. 100 days later, the only person on that raft who had behaved the way he predicted was him.

[00:00:44]Santiago Genovés was a Mexican anthropologist >> [music] >> who had spent his career studying human aggression.

[00:00:51]He was born in Spain in the middle of a civil war, raised in a country that had just torn itself apart.

[00:00:57]Violence was not an abstraction to him.

[00:01:00]It was the context he grew up inside.

[00:01:02]In 1972, he was on a plane that was hijacked by five armed men. The hijacking was resolved. Nobody died.

[00:01:10]But Santiago had watched what happened to people when the situation became genuinely dangerous.

[00:01:16]How quickly the ordinary rules disappeared. How fast people revealed something they usually kept hidden.

[00:01:22]He had also been reading research on aggression in male primates.

[00:01:25]>> [music] >> Studies suggesting that violence in male monkeys was driven by competition for access to fertile females.

[00:01:31]The males fought because the females were there.

[00:01:34]Three things had shaped his thinking. A civil war, a hijacking, and experiments on monkeys.

[00:01:40]From these, [music] he built a hypothesis. Under conditions of danger and confinement, humans would revert to their base nature.

[00:01:48]>> [music] >> Men would compete sexually, violently, for access to women.

[00:01:53]Given enough pressure, enough time, >> [music] >> the competition would turn into something uglier. He wanted to prove it.

[00:01:59]He lobbied. He was told no. He came back with a different argument. He reframed the whole thing as a social experiment, submitted [music] it again, and this time it was approved. He designed a raft, 12 m long, 7 m wide, small enough that 11 people would have no personal space at all. Beds side by side, men and women alternating. No books, no individual activities.

[00:02:21]>> [music] >> Any free time had to be spent in social interaction. He named it the Acali.

[00:02:26]In the Aztec language, it meant house on the water. He deliberately gave women the important roles.

[00:02:32]The captain was a woman.

[00:02:34]The radio operators were women.

[00:02:36]The diver was a woman. The men were assigned the physical labor, the deck work, the hauling.

[00:02:41]His reasoning, reversed the traditional power structure, put men in subordinate positions, [music] watched the resentment build.

[00:02:48]He also chose the departure date carefully, storm season. He wanted to see itself to be a threat.

[00:02:54]>> [music] >> And he chose not to include a motor.

[00:02:57]The Acali would cross the Atlantic on currents and [music] wind alone, from the Canary Islands off Africa to Mexico.

[00:03:03]Roughly 100 days.

[00:03:05]No way to leave early.

[00:03:08]On May 11th, 1973, [music] the Acali set out with 11 people on board.

[00:03:13]Santiago settled in to watch.

[00:03:22]The first days were easy. People introduced themselves, shared stories, sang songs.

[00:03:28]The kind of surface bonding that happens when strangers are forced into close proximity.

[00:03:33]Santiago observed from a distance. He said almost nothing. He had promised the group he would not interfere.

[00:03:40]He was the scientist. They were the subjects.

[00:03:43]His job was to watch.

[00:03:45]He did not keep that promise.

[00:03:48]20 days in, the initial [music] energy had faded. The stories had been told, the songs had been sung. People were restless. The ocean stretched in every direction. There was nowhere to go.

[00:04:00]Santiago began to feel hopeful. He knew that boredom could produce strange behavior.

[00:04:05]He watched for signs.

[00:04:07]There were some.

[00:04:08]Charles, who was engaged, had begun flirting with Rashida. The ship's doctor, Edna, had slept with two different men on the raft. Santiago wrote furiously.

[00:04:18]This was it.

[00:04:19]The competition was beginning.

[00:04:21]He went back to his notebook. He started tracking patterns. He was certain. Give it a few more days and the mask would come off. Men would start competing.

[00:04:30]Tensions would surface. The hypothesis would hold. But the competition he had predicted didn't come.

[00:04:36]The other men didn't react. Nobody felt threatened.

[00:04:39]Edna said later that the sex had nothing to do with desire or competition. It was something to do. Boredom, not passion.

[00:04:47]The others shrugged and moved on.

[00:04:49]This was not what Santiago had expected.

[00:04:52]He started asking questions. Personal questions. Direct questions.

[00:04:57]Who do you find attractive on the raft?

[00:04:59]Have you been stimulated by anyone here?

[00:05:01]The group answered politely. Nothing escalated. So, Santiago got more creative.

[00:05:12]He started moving information between people.

[00:05:14]In private conversations, people said things about each other. Small things.

[00:05:19]Honest things. The kind you say when it's just the two of you.

[00:05:23]Santiago took those things and repeated them in front of the group.

[00:05:27]Edna had told him privately she found Jose attractive.

[00:05:30]Jose had told him privately that he found Edna's constant talking irritating.

[00:05:35]Santiago called a group meeting and said both things out loud to everyone.

[00:05:40]Edna and Jose looked at each other. Then they both laughed and moved on.

[00:05:45]Santiago tried again.

[00:05:47]And again. he carried gossip from one side of the raft to the other, planting small tensions, hoping they would root and grow.

[00:05:55]They didn't.

[00:05:56]When gossip failed, he escalated.

[00:05:58][music] He threw buckets of water at people without warning or explanation.

[00:06:03]He made racist remarks to Faye, a black woman from the United States, suggesting she and Bernardo, the Angolan priest, would be suited to each other.

[00:06:12]He pressed every button he could find.

[00:06:14]The group grew colder toward him.

[00:06:17]More patient, in the way people are patient with someone they have collectively decided is not worth engaging.

[00:06:23]They endured him.

[00:06:24]They did not break.

[00:06:27]The rudder broke.

[00:06:28]Somewhere in the middle of the Atlantic, a part underneath the hull came loose.

[00:06:33]It needed to be fixed from below the waterline.

[00:06:36]That was the diver's job.

[00:06:39]Servi prepared her equipment. Santiago intervened. He told her to stand aside.

[00:06:44]He would handle it. He put on the snorkel, but his beard was too thick.

[00:06:48]The seal didn't hold.

[00:06:50]Water seeped in with every dive. He went down, came up, went down again.

[00:06:56]He spent hours on the problem and did not solve it. He told the group he would finish it tomorrow.

[00:07:01]That night, while Santiago slept, Servi put on her snorkel, went into the water, and fixed the rudder in 5 minutes.

[00:07:08]When Santiago found out, he accused her of insubordination. She had fixed the rudder in 5 minutes, while he had failed to do it in hours.

[00:07:17]Not long after, a cargo ship appeared on the horizon, moving fast, not changing course. It was heading directly toward the Acali. Santiago froze. He shouted without direction. He gave no orders.

[00:07:29]Maria, the captain, took over without a word. She organized the flares, directed the radio operators, coordinated everything in the time it took Santiago to stop panicking.

[00:07:39]The cargo ship [music] saw them and changed course.

[00:07:41]The raft was safe.

[00:07:43]That evening, Santiago announced to the group that he [music] was taking command of the Acali. He said it clearly in front of everyone.

[00:07:51]Maria looked at him. The others looked at Maria.

[00:07:54]Nobody acknowledged it.

[00:07:56]The next morning, Maria continued doing her job as captain.

[00:07:59]Nobody said a word.

[00:08:05]A storm came.

[00:08:06]>> [music] >> Maria assessed the situation and told the group they should move toward shore, wait for the worst of it to pass, then continue.

[00:08:13]Santiago overruled her. He said the experiment couldn't be compromised. The conditions were part of the design. He said they would stay the course. Maria argued. Santiago shouted. The raft [music] stayed at sea. Later, up on the roof of the raft, out of Santiago's earshot, the group had a conversation.

[00:08:33]They talked about everything he had [music] done. The gossip, the racist remarks, the water throwing, the rudder, the cargo ship, the storm decision. They talked about the fact that he had put their lives at risk for an experiment [music] that wasn't working.

[00:08:47]And then someone said it.

[00:08:49]What if we just killed him?

[00:08:51]It was Faye who suggested the method.

[00:08:53]Everyone holds the knife together.

[00:08:55]Everyone is equally responsible. No single person carries the guilt.

[00:08:59]>> [music] >> They talked about it seriously.

[00:09:02]Drowning, poison, an accident at sea.

[00:09:05]In the end, they decided against it. Not because they had forgiven him, because they had decided he wasn't worth the weight of it. They could manage him for the rest of the journey.

[00:09:15]They came down from the roof. Santiago took notes.

[00:09:18]>> [music] >> He didn't know what had just been discussed a few feet above his head.

[00:09:23]The Acali reached Mexico on August 20th, 1973.

[00:09:27]101 days at sea.

[00:09:30]The participants went their separate ways. Several stayed in contact.

[00:09:34]>> [music] >> Some became close friends. Mary, who had joined the voyage to escape a violent marriage, [music] went home and filed for divorce. Santiago's career did not recover. He remained a working academic, but the stature he had been building toward never came. The experiment he had designed to prove his hypothesis had instead disproven [music] it and documented in the process exactly the kind of behavior he had been looking for in others.

[00:09:59]He had been the subject all along.

[00:10:02]In 1965, years before the Acali set out, six boys from Tonga were stranded on an uninhabited island for 15 months. They built shelters, resolved their disputes, and came home alive.

[00:10:14]Nobody turned savage. The Acali group had been given every reason to fall apart. Confined space, no privacy, >> [music] >> storm season, and a man in their midst actively trying to make them hostile.

[00:10:27]They didn't fall apart. [music] They organized. They looked after each other. They even looked after him.

[00:10:33]Santiago Genoves spent [music] 3 months trying to make 11 people turn on each other.

[00:10:39]They didn't. He just hadn't been looking in the right place.

[00:10:43]There are more stories like this.

[00:10:45]We'll keep telling them.