No two human brains are identical – each one of the 7.5 billion humans on earth has a unique pattern of neural wiring and encoding that provides a personalized view of the world, odd quirks and all. Studies have measured variations in human traits such as IQ scores, attention span and empathy – even variation in how our eyes and brain process the colors we see. This “neurodiversity” is thanks to both genetic diversity – the combination of genes that we’ve inherited from our parents – and what we’ve been exposed to during our lifetimes.
But could science be used to reduce neurodiversity? And should it try? Already, many conventional drugs, such as cognitive enhancers, stimulants and antidepressants, act to reduce certain elements of neurodiversity. Non-invasive prenatal testing and other forms of genetic counseling also achieve that goal, typically to reduce the risk of passing along genetic diseases, while pre-implantation genetic testing selects specific genetic traits in babies.
New human enhancement and genetic technologies – notably CRISPR – are advancing at a rapid rate. Five gene therapies are already approved for clinical use in the US or Europe for some types of cancers and retinal disease, and many hundreds more are being tested. In mice, gene-editing techniques have been used to eliminate traumatic memories and implant new memories. More than a dozen single-gene variants (some not found in nature) have been shown to improve performance on one or more cognitive tasks in animals. Some also delay cognitive decline and are moving into clinical trials.
As research on the genes underlying normal cognitive, personality and social traits progresses, it’s possible that gene-editing will give us the power to select even more such traits. If parents want a designer baby with genes to maximize their intelligence, creativity and even personality, technology could make it possible. But what skills might be unintentionally lost, and what does this mean for humankind?
Neurodiversity underlies the powerful wisdom of crowds. Studies have shown that averaging solutions from a diverse group of people results in more accurate solutions. Diverse thinking leads to diverse capabilities – variations in the art, technology, and consumer products that people imagine and engineer. Quirks allow us to see things in a different light, fueling creativity, innovation and progress.
Certainly, it’s appropriate to argue for the ethical use of genetic advances to alter or eliminate schizophrenia, bipolar disorder, autism, obsessive compulsive disorder, dementia and other mental conditions that cause millions to suffer. But just as certainly, tinkering with the diversity of normal behavioral traits or states in people without illnesses, even making small adjustments, could unleash unintended consequences and ethical dilemmas.
Pursuing this avenue of research might be eased with advances in medical science and gene-editing techniques that could be deployed strategically. For example, rather than using genetics to completely eliminate certain traits or states of mind – those which don’t convey disability but render certain tasks difficult –the approach could instead dial these traits up or down. We might want to instill insensitivity to pain or diminish deafness, or to finely control concentration, creativity, memory, sleep, (day)dreams, or even blood flow and temperature in case of injury.
But the challenge is, as always, where to draw the line between an acceptable and unacceptable characteristic, and who draws that line? For every successful inventor with subclinical, mild ADHD or bipolar traits, there are millions who suffer the disabling consequences of ADHD and bipolar disorder. But where is the border between genius and disorder? Would it be ethical or even appropriate to conduct randomized trials to see what traits should be eliminated and which ones should not be? And what is CRISPR’s role in basic human feelings and beliefs such as love, hate, prejudice and spirituality? These are issues we have to consider carefully.
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Today in Silicon Valley, it is widely recognized that people who think differently change the world. The bottom line is two-fold. Clearly, new genetic technologies offer people the promise of richer lives with a decreased risk of some serious diseases and disabilities. But if we want our richly creative and innovative world to thrive, we should also seek ways to embrace and preserve our diverse traits. Our future may depend on how well we can balance these needs.