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  • Writer's pictureSociety of Bioethics and Medicine

On the Ethics of Neural Twins

Written by Nishanth Araveti

Edited by Jacquelyn Tang

First proposed by philosopher Derek Parfit, the Teletransporter Thought Experiment supposes the existence of a machine that, upon entering, would clone you perfectly; all memories, neurons, every atom of you perfectly replicated and subsequently replicated on Mars before incinerating the body that stepped in on Earth. Are you on Mars? Or is it a different you that stepped out on Mars? At the root of this problem is the concept of self and how we define our identity — what is it that makes us so unmistakably us? The ability to fully clone a human is still rather far off, but the ethical concerns of the rights and status afforded to replicants remain valid to this day with the rise of cloned organs and AI’s with neural structures approaching the asymptote of human thought.

Virtual twins (the simulated counterparts of everyday, real world objects) have long been the norm in various industries – their capabilities allowing for the prediction and treatment of critical issues in everyday functioning that would otherwise be near impossible to predict. Used in everything from city planning to wind turbine engineering by modeling the effects of certain external factors (like the spread of disease) or predicting failure (blade failure in a progressively-worsening turbine), digital twins create a far more detailed output of information than a simple, one-dimensional simulation— the difference being the multitude of data flowing through the designed system in real-time. Now, new initiatives seek to create digital twins of the human mind itself to observe and preemptively treat any hidden conditions arising from genetic factors or chronic neuropsychiatric disorders, like Alzheimers by taking data from a litany of sources (fMRI’s, Calcium Imaging, PET Scans) and creating personalized brain models.

Despite the readily apparent use, the initiative raises questions on the rights of these artificial intelligences and the ethics behind cloning. For starters, who owns the neural twin? Should the person be informed if the neural model predicts death? Does a neural twin deserve to be afforded the same rights as a person? Ultimately, the issues touch not only on the concept of self and the ethical dilemmas surrounding cloning, but also on the same problems that govern the possession of genetic material and gene patents.

Perhaps the most pressing question, however, is not one of legality, but of identity – which of the two minds, visual or physical, is the self? What happens to the twin when the person were to die or vice versa? In many ways, this question is mirrored by Parfit’s thought experiment and attempting to answer such a question requires us to become familiar with theories of one’s self.

It is also worth noting the similarities between issues of personhood following significant neurological events and issues of personhood following digital twinning. In Alzheimer’s and Dementia, both memories and personality are affected to the point where establishing relative identities becomes a muddled mess dependent on a variety of factors. Should the current beliefs of the patient be acknowledged or the past beliefs prior to the disease? Are they still the same person? With virtual twins, we face the same issue following significant events like death and the moment of replication. While the difference may seem intuitive, our intuition is predicated on the continuity of self — already a dubious proposal.

One theory, proposed by Charles Taylor, argues that a person is defined, not by the physical body or memories, but rather by the narrative that surrounds the subject of our investigations. In this theory, called the Situation-Embodied-Agent Account , the continuity surrounding the embodied self remains important, but specifically when defined by the person’s reactions to the circumstances surrounding them and the narrative that others project onto them. While people can change, it is generally regarded that they are the same person as before — regardless of how much dementia might have affected them.

Another theory, proposed by Parfit himself, scoffs at the notion of a stable personal identity. Parfit proposes that what matters is not the ability to influence the world or the ability to affect situations similarly to previous versions of yourself. Rather, Parfit argues that the notion of an unchanging root of self does not exist — instead seeing identity as a gross collection of lived experiences, memories, and the like that are untethered by a core aspect of being/self but come together, nonetheless, to form a variable and ever shifting definition of personal identity. By this logic, people suffering from serious mental illnesses can be said to be conclusively different people than before because the elements that have made them who they are have either disappeared or been changed.

By views of this theory then, the digital twin fails to satisfy the conditions required to declare identical or continuous personhood with the original body — its creation designated as a continuity-breaking identity because it does not possess the lived experiences of the original. Ultimately though, under another theory, the virtual twin retains the possibility of being recognized as the person under certain specific and highly unlikely (but still notable conditions.) After all, if the virtual twin was given the tools to affect the real world, act a specific way in certain situations, and following the death of the original, does the conferring of personhood not have deeper implications? Have we found a way to make ourselves functionally immortal?


Browne, Grace. “The Quest to Make a Digital Replica of Your Brain.” Wired, Conde Nast, 15 Feb. 2022,

Hughes, Julian C. “Views of the Person with Dementia.” Journal of Medical Ethics, Institute of Medical Ethics, 1 Apr. 2001,

J;, McMahan. “Cloning, Killing, and Identity.” Journal of Medical Ethics, U.S. National Library of Medicine,

J;, Savulescu. “Should We Clone Human Beings? Cloning as a Source of Tissue for Transplantation.” Journal of Medical Ethics, U.S. National Library of Medicine,

Robert Cook-Deegan, MD. “Gene Patents.” The Hastings Center, 23 Apr. 2018,

“What Is a Digital Twin?” IBM,


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