> In science, you go out of your way to control for confounding factors. There's tons of observational science done in a very similar fashion to the article wh

> In science, you go out of your way to control for confounding factors. There's tons of observational science done in a very similar fashion to the article where there is simply no way to control for confounding factors for the same reason that there is simply no way to properly control for it in the data available.