The data shows that more than 600,000 people got arthroscopic knee surgery in the US in 2010. It's expensive and painful.
It turns out that sham surgery works just as well. That just about as many people would have found pain relief from this procedure if they had experienced fake surgery instead.
In an extensive study of elective surgeries (asthma, obesity, Parkinson’s disease, acid reflux and back pain) it was found that more than half the time, people would have had at least a good an outcome if they had only experienced fake surgery instead of the real kind.
That's worth a pause.
Same operating room, same gowns, same perception of pain–but no actual surgery. Half the people would have gotten better, which is awfully close to the number that got better from the real thing.
(Even if this number is twice as high as you are comfortable with, it tells us something dramatic about the power of suggestion).
If you don't think marketing works, and you're wondering about the power of the placebo, that's all the evidence you should need. That sham surgery on knee pain is virtually as effective as the real kind. Which means it's not a sham at all, is it?
Of course, placebos work on far more than knees. They work on the taste of wine, the effectiveness of coaching and how well we perform at work.
When they say "it's all in your head," they're actually being optimistic and encouraging. If it's in your head, you can do something about it.