Shipwrecked sailors tell stories of being too exhausted to swim further, saved by dolphins pushing them to shore. Dolphins have a reputation for being friendly to humans. We don't hear from any sailors who would have made it shore if not for the dolphins who kept pushing them out to sea until they drowned.
In World War II, the RAF analyzed the location of bullet holes in planes. Mathematician Abraham Wald realized that the initial recommendation to armor the areas that took the most fire was exactly wrong. We only see the planes that returned. The bullet holes we see are in places that are survivable. It is the other areas, where we don't see damage, that would cause the plane to go down when hit.
Selection bias is a natural consequence of basing belief on our perceptions. In our AcroYoga community, people come and go all the time. Many of us travel extensively. Some people try it for a while and move on. Occasionally, someone gets hurt and leaves. But we never know why someone does not return.
The one time I told a yoga teacher that their adjustment the previous week left me in pain for several days, he responded with denial: Something else you've done must have caused it. Most students, myself included, find it easier to not return to class and avoid confrontation.
If we base our risk assessment when we are seeing only the survivors, our judgement of risk is skewed.
If we want to make our sport safer, we need to change the culture to normalize talking publicly and collectively about what can go wrong and how we get hurt. Everyone has their own stories of accidents and what they've learned from them. If we pool that wisdom, we will all be the safer for it.
This injury study will create a database of AcroYoga injuries we can all learn from. If we encourage everyone to share their stories, that is a step towards a stronger culture of safety. Please take a look and share your own experience.
The AcroYoga Curmudgeon