The Power of Beliefs

Chapter 1

The Power of Beliefs Is Ascending

Beneath the noise and bustle of modern progress, something unexpected, and quietly extraordinary, has emerged. Scientifically, yet largely unnoticed, the power of our beliefs has been rising steadily for two decades.

In the modern world we can now peer inside the brain, edit genes, and teach machines to think, yet we struggle and often fail to find meaning, change habits, and sustain joy. Surrounded by the tools and triumphs of technology like MRIs, SSRIs, and AI, we easily assume that the impact of “mere belief” on our future is fading. But the research tells a different story. Beliefs are the hidden key.

Stunning new research reveals just how powerfully our deepest assumptions about the world and ourselves shape our future lives. These “core beliefs,” both empowering and limiting, are now increasingly predictive of our future health, success, and educational outcomes. Beliefs don’t just shape our perceptions; they scientifically change the probabilities of our actions and future outcomes. In short, beliefs change the math about what is possible and probable. By changing the math, beliefs change our path . . . .

The Rise of Belief

Back in 1955, a Harvard Medical School anesthesiologist named Henry Beecher published a study in The Journal of the American Medical Association that irrevocably changed the field of medicine. In “The Powerful Placebo,” Beecher suggested that “placebos”—fake drugs or interventions that the patient believes are real—create a real and quantifiable outcome change compared to the control group who receives no treatment. In the fifteen studies Beecher performed on more than a thousand participants with different diseases, the placebo group had a positive benefit 35 percent of the time compared to the control group. This was and remains a stunning conclusion.

Beecher had begun the process of quantifying the impact of belief on outcomes. Decades later, placebos still serve as powerful examples of how beliefs can change our outcomes.

One striking instance comes from a 2002 study led by Dr. Bruce Moseley, an orthopedic surgeon at the Baylor College of Medicine. In this study, published in The New England Journal of Medicine, one hundred eighty patients who had suffered for years with severe knee osteoarthritis were offered a free knee surgery. Sounds great so far! The catch, they learned, was that only two-thirds of them would receive a real surgery.

One-third would have cartilage removed and another third would have an arthroscopic lavage to clean out the knee debris—both standard procedures repeatedly found to be better than time and natural healing. The final third would receive a “sham surgery” where nothing was done. Instead, an incision would be made by Moseley while the patients were under anesthesia, leaving a scar so the patient had no way of knowing if they received one of the real surgeries or not.

If you think it is crazy that this study got approved, you are not wrong. But participants were given a 66 percent chance to get a free life-changing surgery knowing that they wouldn’t just naturally get better without it.

It somehow gets crazier. At the six-month mark, the patients who received the sham surgery showed the same improvement in their pain, inflammation, and mobility as those who received a real surgery. The same result held at one year. Even two years later, the patients who falsely believed they received a knee surgery experienced the same improvement as the real procedure recipients. You may be wondering if the “sham surgery” patients just naturally healed? Not in this case. Severe osteoarthritis is a progressive condition that naturally gets worse over time, not better.

The durability of the placebo effect in this study surprised many in the medical community. The placebo hadn’t just provided a brief psychological boost—it had the same lasting power as an actual invasive but effective procedure. This was not a rejection of knee surgery; it was an astonishing potential validation of the power of belief.

Nowadays, the Federal Drug Administration requires all new drugs to be tested against a placebo. I find this fascinating. I began my graduate work at Harvard Divinity School studying ethics—how the lens through which people view the world changes what happens next. In the ancient world, without testing and controls, there was no way to know for sure if the positive effects of a healing were due to the herbs, a ritual dance, or simply a belief that the treatment would work. I point this out not to suggest that ancient medicine didn’t work, but to note that in the modern world, we did not cut beliefs out of the formula. In fact, at the cutting edge of biotechnology, the gold standard for testing a new drug requires comparing its effectiveness to the power of belief.

And this is where things take a huge turn.

Sixty years after we started measuring the placebo effect, scientists began to notice the emergence of an even more surprising effect. In 2011, a group of French researchers released a comprehensive analysis of dozens of childhood epilepsy studies. Instead of focusing simply upon the efficacy of the drugs, the researchers also tracked the placebo groups. To their shock, they found that across these many studies, the placebo effect had increased significantly over time. In 1990, 10 percent of these patients who took the placebo noticed an improvement in the frequency of seizures. Twenty years later, that rate was slightly above 20 percent. The placebo had seemingly doubled in efficacy in two decades.

Shortly after, another study was published in the esteemed scientific journal Pain. Researchers reexamined eighty-four different published studies over the past two decades and were forced to conclude that, since 2000, the impact of placebos has steadily increased so that all types of human pain, from neuropathy to headaches to healing after surgery, have lessened. Since then, researchers from Harvard to Oxford—looking at hundreds of studies of dementia, depression, headaches, backaches, knee pain, shoulder pain, eczema, acne, multiple sclerosis, heart disease, and cancer—have found that the power of placebos is rising across the board. In one meta-analysis of seventy-five studies, the effect of a placebo on clinical depression has been increasing by 7 percent per decade!

That is stunning. Why would belief be having an increased impact on our outcomes? The drug companies would have no reason to falsely build up the placebo effect. That would make it harder to approve new drugs. And there is no reason to assume that a placebo like a fake pill or fake knee surgeries would work better in 2025 than in 1925. The placebo effect should not change over time.

But it did. And it continues to increase.

The internal mechanism of why placebos work is still a mystery to scientists. Some say when we believe we have received a treatment, this calms down the parasympathetic nervous system and heals us, or that the belief that we are being healed gives us confidence to be more active, which in turn heals us. Either way, beliefs are having a quantifiable impact.

This book is not about placebos. To me, the truth is more powerful than lies. But the conclusion is already astounding. It’s not just that belief is powerful. It’s that, for some reason, belief may be becoming more powerful and impactful in our modern world.

Okay, now stop for a moment. Would you have guessed that? Or would you have assumed that the power of belief is waning in the modern world? For many, modernity is defined as the progression of science, technology, and medicine over things like mere beliefs. And some argue that with AI and deepfake technology, we live in a world where you can’t believe anything. (I’ve seen a video of Elon Musk making out with a polar bear, and that’s on an app he owns and controls.) We are starting to not believe even our own eyes, ears, and apps.

Yet when we research the impact of belief on our health outcomes, its power is actually growing. But it doesn’t stop there: Beliefs are not just affecting our health, they are affecting our outcomes throughout our lives in new and extraordinary ways.