Perhaps the most troubling experiment in recent history is the dolphin-intelligence study conducted by neuroscientist John C. Lilly in 1958. While working at the Communication Research Institute, a state-of-the-art laboratory in the Virgin Islands, Lilly wanted to find out if dolphins could talk to people. At the time, the dominant theory of human language development posited that children learn to talk through constant, close contact with their mothers. So, Lilly tried to apply the same idea to dolphins.

For 10 weeks in 1965, Lilly’s young, female research associate, Margaret Howe, live with a dolphin named Peter. The two shared a partially flooded, two-room house. The water was just shallow enough for Margaret to wade through the rooms and just deep enough for Peter to swim. Margaret and Peter were constantly interacting with each other, eating, sleeping, working, and playing together. Margaret slept on a bed soaked in saltwater and worked on a floating desk, so that her dolphin roommate could interrupt her whenever he wanted. She also spent hours playing ball with Peter, encouraging his more “humanoid” noises and trying to teach him simple words.

As time passed, it became clear that Peter didn’t want a mom; he wanted a girlfriend. The dolphin became uninterested in his lessons, and he started wooing Margaret by nibbling at her feet and legs. When his advances weren’t reciprocated, Peter got violent. He started using his nose and flippers to hit Margaret’s shins, which quickly became bruised. For a while, she wore rubber boots and carried a broom to fight off Peter’s advances. When that didn’t work, she started sending him out for conjugal visits with other dolphins. But the research team grew worried that if Peter spent too much time with his kind, he’d forget what he’d learned about being human.

Before long, Peter was back in the house with Margaret, still attempting to woo her. But this time, he changed his tactics. Instead of biting his lady friend, he started courting her by gently rubbing his teeth up and down her leg and showing off his genitals. Shockingly, this final strategy worked, and Margaret began rubbing the dolphin’s erection. Unsurprisingly, he became a lot more cooperative with his language lessons.

Discovering that a human could satisfy a dolphin’s sexual needs was the experiment’s biggest interspecies breakthrough. Dr. Lilly still believed that dolphins could learn to talk if given enough time, and he hoped to conduct a year-long study with Margaret and another dolphin. When the plans turned out to be too expensive, Lilly tried to get the dolphins to talk another way—by giving them LSD. And although Lilly reported that they all had “very good trips,” the scientist’s reputation in the academic community deteriorated. Before long, he’d lost federal funding for his research.