HEALTHY PEOPLE WITH LESS PAIN
Patients who experience little to no pain often live very difficult and dangerous lives. However, there are rare exceptions, people who can help researchers design new non-addictive painkillers and gene therapies.
Jo Cameron has never felt pain, even after bone-breaking surgeries and car accidents. Childbirth was "a tickle." Jo seems invincible to all available tests of negative experience, including anxiety and depression, yet she is healthy, intelligent, and maintains all other sensations. She is slightly forgetful and accidentally acquires minor burns when cooking. However, she also heals faster from such injuries as result of her mutations.
Like most genetic traits, pain sensitivity is a spectrum. Jo's son, Jeremy, is also significantly less sensitive to pain. However, he only carries one of her mutations, likely underpinning his attenuated condition. This points to the existence of many pain-volume settings, rather than a binary on/off switch. Rather than eliminate pain forever, future therapeutics will aim to dial down pain to levels appropriate for patients with chronic pain disorders, as well as those undergoing surgery, chemotherapy, and other procedures.
It might be more adaptive for pain to last longer, but for the Marsili family, broken bones only cause pain for a few seconds at most. Like the Camerons, the Marsilis lead fairly normal lives. As far as we know, they have not suffered any serious permanent damage because of their lack of pain.
Together, the Camerons and Marsilis can inspire us to explore how much pain is necessary for optimal health, both in terms of its intensity and duration. Like the advent of anesthesia and modern pain pharmacology, genetic therapeutics for pain and suffering are likely to dramatically improve the human condition.
Given that humans and other animals share many of the same pain genes, therapeutic insights can be used to alleviate pain pathology in domestic animals too. How much pain is considered necessary for an animal depends on their environment. To survive and pass on their genes, many wild animals likely need more pain than those in confined environments. However, even some wild species have evolved to endure less pain. Domestic animals could be bred in a way that screens against pain disorders.