Apples and Oranges

One of the things you learn right away in a class on experimental design, is not too include too many variables.  If you want to test the effects of a certain treatment, better to test on organisms as similar as possible so you can be sure you’re measuring the effects of your treatment, rather than something else.  

Apple trees may respond differently than orange trees to a certain fertilizer, because they are reacting to soil conditions, temperature, and insects as well as the fertilizer.  Maybe one tree just grows more slowly than the other.  So, when you want to discuss how much the trees are affected by fertilizer application, you also have to acknowledge all these other differences.  Your experiment doesn’t tell you much, except that apple trees are different than oranges trees and we already knew that...didn’t we?  Best to pick one type of tree in the same field with similar light and water and soil conditions and then look at fertilizer effects (and it could be compost, so don’t worry about this being an inorganic example).

Judging by revelations of the last week, including Yoga Dawg’s link of “average” yoga teachers’ salaries (and the vastly superior correction), and It’s All Yoga Baby’s discussions (here, and here) of the NYT article about yoga injuries (apparently, hour-long inversions are bad for your neck!), the notion of difference and variability is often forgotten when the topic is yoga.  I’m not sure you can average anything or use blanket statements for yoga, but that doesn’t seem to stop the critics.

Skeletons are hooked up differently, joints have different amounts of mobility, digestive systems process fats differently, teachers have different hourly schedules, Iyengar is different that Bikram.  Surprise!  If you want to measure anything, discuss anything for comparison, how about controlling for a few of those variables, so your conclusion actually has meaning.  

Of course if you do yoga consciously and participate in the yoga community, you know most of this stuff is pretty silly anyway.  Generalizations make better press, and clarifying details make headlines and search terms so complicated and boring.  It  wouldn’t be half as compelling to discuss how a well-trained, carefully-taught class can be so beneficial (or not, studies seem to show that you have to believe yoga will help you, for it to actually help you).  Or to show a break-down of teacher salaries based on region, or place of employment, or class size.  Can’t sell as much advertisement.

So that’s my take.  Yeah, people sometimes get hurt doing yoga.  Sometimes they don’t.    What’s really interesting is why...and if you’re comparing apples and oranges your answer is going to be a lot broader and have a lot less meaning than a look at what’s going on between those two Pink Ladies.  Narrow the focus, people!