If you’re looking for the answer to the classic riddle, here it is: the scientist created an exact duplicate of himself because he was “beside himself.” It’s a pun, playing on the phrase meaning someone is overwhelmed with emotion and the literal image of standing next to your own copy. But the riddle touches on something surprisingly real. Several scientists have actually built duplicates of themselves, and their reasons go far beyond a punchline.
The Roboticist Who Copied His Own Face
Hiroshi Ishiguro, a robotics professor at Osaka University, built a lifelike android replica of himself called the Geminoid. It looks like him, moves like him, and can even mimic his speech patterns. His stated motivation: “My motivation for making humanoid robots stems from an interest in understanding what makes us human, and what it means to be human.”
What happened next surprised him. Everyone who saw the Geminoid commented on how closely it matched his appearance and behavior, but Ishiguro himself disagreed. He didn’t think it looked like him at all. That disconnect became his most important finding: we don’t really recognize ourselves. We don’t truly know our own appearance, voice, or movements the way other people perceive them. The duplicate became a mirror that revealed how poorly we understand our own identity.
Beyond that philosophical insight, the Geminoid serves as a tool for psychological experiments on how people interact with humanlike machines. Research into what’s called the “clone devaluation effect” shows that seeing identical faces triggers a distinct sense of eeriness in observers, rating significantly higher on unease than seeing a group of different faces. That discomfort appears linked to a deep, almost instinctive reaction to something that looks human but violates our expectation that every person should be unique.
The Robot Built to Outlive Its Human
Entrepreneur Martine Rothblatt took a different approach. She commissioned BINA48, a robotic bust modeled after her wife, Bina Rothblatt. The robot was loaded with “mindfiles,” a database built from extensive interviews capturing Bina’s memories, opinions, and personality. The goal wasn’t scientific curiosity. It was a proof of concept for life extension: the idea that a person’s mind could be uploaded into a more durable substrate than a human body, effectively letting someone persist beyond biological death.
BINA48 can hold conversations, express preferences, and respond to questions using the information from those interviews. It’s not a conscious being, but it represents one answer to the question of why you’d duplicate a person: to keep some version of them present after the original is gone.
Digital Twins Built for Medicine
The most practical reason scientists create duplicates of people has nothing to do with robots. Digital twins are virtual models of individual patients, built from their genetic data, medical records, wearable device readings, and other health information. These aren’t physical copies. They’re computer simulations designed to predict how your specific body will respond to a drug, a surgery, or the progression of a disease.
The applications are already in use across Europe and expanding fast. A digital twin of your heart could let a surgeon simulate the effects of a pacemaker before implanting one. A model of your metabolism could predict how you’d respond to a diabetes treatment. Researchers have used computational fluid dynamics to build personalized risk models predicting whether small brain aneurysms are likely to rupture in specific patients. The European Commission is actively funding a platform to integrate and validate these virtual human twin models across the continent, with access to supercomputing power for advanced modeling.
The core idea is simple: instead of guessing which treatment will work based on population averages, doctors can test options on your digital duplicate first. Digital twins can also function as early warning systems, flagging when data patterns suggest a patient is developing a chronic condition or when a prescribed treatment isn’t producing the expected benefit.
Cloning: The Biological Duplicate
When people imagine a scientist literally creating an exact duplicate, they’re usually thinking of cloning. No scientist has cloned a human being, but the technology exists in animals, and the reasons researchers pursued it reveal a lot about the motivation behind duplication.
Reproductive cloning produces genetically identical copies of whole animals. The Scottish team that cloned Dolly the sheep went on to clone sheep genetically modified to produce human blood-clotting proteins in their milk. Cloned animals also offer a major advantage for drug testing: because they’re genetically identical, their responses to medications are uniform rather than variable, making it easier to isolate a drug’s true effects. Other goals include rebuilding populations of endangered or extinct species.
Therapeutic cloning has a different purpose entirely. It creates embryonic stem cells that share the donor’s exact DNA, not to produce a whole organism but to grow replacement tissues in a lab. These cells can generate virtually any type of tissue in the body, offering a path toward replacing damaged organs without the risk of immune rejection. They also let researchers study the molecular causes of disease using cells that carry the same genetic vulnerabilities as the patient.
AI Copies That Stand In for Real People
A newer form of duplication involves creating AI agents modeled on real individuals. Researchers at Stanford, Northwestern, and Google DeepMind conducted a study where they built AI agents based on interviews with 1,052 real people. These digital stand-ins replicated the participants’ personalities with impressive accuracy and could be used to simulate how populations would react to policy proposals.
The ambition behind this work is enormous. Complex problems like climate change and pandemic preparedness require understanding how millions of people with different values, circumstances, and reasoning styles will respond to specific interventions. Building accurate digital copies of real individuals and running simulations could let policymakers test ideas before implementing them. As one researcher put it, simulation may finally give us a chance to crack open problems that are otherwise too complex to plan around.
So the riddle’s answer is a groan-worthy pun. But the real reasons scientists duplicate themselves and others range from understanding human identity, to cheating death, to testing cancer treatments on a virtual version of you before touching your actual body. The impulse to create a copy turns out to be one of the most productive questions in modern science.