"The Stanford Prison Experiment: Unlocking the Truth" is a three-part docuseries providing viewers with an unprecedented look at one of history's most infamous psychology studies through the firsthand accounts of the original "guards" and "prisoners," many of whom are speaking on camera for the very first time. Their stories unravel a new narrative that interrogates the motives of the man in charge, Dr. Philip Zimbardo, while exploring larger questions of human nature and the power of perspective. Viewers can watch all three episodes of THE STANFORD PRISON EXPERIMENT: UNLOCKING THE TRUTH on the National Geographic site and stream the complete series anytime on Disney+. Fans can also catch an encore presentation on National Geographic on Saturday, Oct. 24, from 9 a.m. to noon.

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The Stanford Prison Experiment: Unlocking the Truth | Official Trailer | National Geographic

What started out as a self-contained university experiment turned into a media spectacle that captured the imagination and attention of the world, shaping our understanding of human nature and forever changing the field of psychology. There was only one problem: The story of what happened during the experiment was shared with the world by only one person. Today, most of the participants have gone on record to tell … the whole story.

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"In the fifty years since the Stanford Prison Experiment took place, I was surprised to learn that few of the study's participants had ever spoken about their experiences, and that their stories exposed a web of secrets, inconsistencies, and layers that questioned the experiment's seemingly simple narrative about whether human beings are inherently good or evil," said Director Juliette Eisner.  "In light of Dr. Zimbardo's recent passing, this project couldn't be more timely in its exploration of human nature and the repercussions of differing narratives."

Through unparalleled access, THE STANFORD PRISON EXPERIMENT: UNLOCKING THE TRUTH embarks on a gripping, ticking-clock journey through the six-day Stanford Prison Experiment with a deluge of reveals, new subjects and a smoking-gun archive. The docuseries weaves together shocking, poignant and sometimes humorous firsthand accounts from the very participants who were at the heart of the experiment. Then, in an unexpected turn, the series brings the participants to a replica film set of the "prison," where they revisit pivotal moments and attempt to find consensus — and closure — about what really happened over the course of those six days.

In one of his final interviews, the late Dr. Zimbardo, along with his wife, Dr. Christina Maslach, sit down to discuss their own experience. The series offers an unflinching look at Zimbardo's childhood, his motivations for beginning the project, and the notoriety he found in the aftermath.

Episodes of the three-part series include the following:

"THE HALLWAY": Introducing one of history's most notorious psychological experiments — but with a twist. The study's prisoner and guard participants take a seat in front of the camera to reveal never-before-heard details of an event that has shaped our understanding of human nature and good versus evil for the past 50 years. Together, they track the key events that took place over the six fateful days in 1971.

"THE UNRAVELING": What if we told you the Stanford Prison Experiment is not what it seems? The participants reveal new perspectives surrounding what happened in the fateful hallway, putting to question Dr. Zimbardo's long-held claims. With the help of an intrepid French researcher, we learn that the 50-year-old story is riddled with apparent inconsistencies. Meanwhile, the filmmakers expose their own storytelling devices.

"A BEAUTIFUL LIE": In a pivotal interview, Dr. Zimbardo takes a seat in front of the camera and defends his notorious experiment and its lessons. Meanwhile, an unexpected and exciting reunion takes place that exposes new layers of the story. This isn't a tale about an experiment debunked but rather one about the power of perspective and mythmaking.

THE STANFORD PRISON EXPERIMENT: UNLOCKING THE TRUTH is directed by Juliette Eisner and executive produced by Alex Braverman and Juliette Eisner. For Muck Media, Darren Foster, Cristina Costantini, Jennifer Wood and Krista Manis are executive producers. For National Geographic, Josh Cole is executive producer, Bengt Anderson is senior vice president of Unscripted Content, and Tom McDonald is executive vice president of Global Factual and Unscripted Content.

About National Geographic Content: Award-winning and critically acclaimed National Geographic Content, part of a joint venture between The Walt Disney Company and the National Geographic Society, creates and delivers riveting stories and experiences in natural history, science, adventure and exploration. The brand is the largest on social media with over three quarters of a billion followers across all major platforms that generate over one billion impressions each month. Inspiring a deeper connection to the world, National Geographic Content reaches 300 million people worldwide in 180 countries and 33 languages as a digital, social and print publisher and across the global National Geographic channels (National Geographic Channel, Nat Geo WILD, Nat Geo MUNDO), National Geographic Documentary Films, and direct-to-consumer platforms Disney+ and Hulu. For more information, visit natgeotv.com or nationalgeographic.com, or follow Nat Geo on Facebook, X, Instagram, YouTube and LinkedIn.