Friday, March 25, 2011
The problem with observations
I look at the pictures out there of all the swimmers who have made a splash. I note that they tend to be long, lean folk and have what's commonly called a swimmer's build. I, myself, want a swimmer's build, so it makes sense for me to take up swimming! Right? If I swim enough, I will develop a swimmers build!
This is a common mistake humans make about observations. We assume that swimmers got their build by what they do. But in actual fact, if you go to a swim meet and watch all the swimmers in all the qualifying rounds, you would see practically every sort of body build there is. As competitors swim in each succeeding competitive heat, an evolution of appearance happens. Winners of each race tend to become more and more similar in build until the championship race, to us, it appears as though all the swimmers have the same type of body.
There is a body type that's well suited to doing well at swimming and that's what we've seen. Those born with a swimmer's build tend to do better at this sport. They're good at swimming in part because they started out long and lean. They didn't get that way as a result of what they did! This is the fallibility of human observation. And we need to remember that fallibility when we're looking at scientific studies, for that same problem can crop up there, too. Just because things happen together, doesn't mean they are cause and effect!
Media is very prone to this sort of jumping to conclusions. Scientists do it too, sometimes, especially when their funding is involved. To top it off, in scientific studies--especially about nutrition--it's very complex what people eat and hard to figure out all the possible variables. They're called confounding factors. Suppose they do a study that concludes that people who eat less meat have fewer heart attacks. Can we conclude that meat causes heart attacks? What if it turns out that the people in this study who eat less meat, are also way more health conscious than the other group which contains a lot of smokers and drinkers. Now what does it tell us? Hmmm.
It pays to be very cautious about drawing conclusions. Interpretation killed a lot of great theories. Like I have to swim to get a swimmer's build. It turns out, I have to pick my parents to get that swimmers build!