The statisticians who discovered causality were trying to find a way to distinguish, within survey data, the direction of cause and effect - whether, as common sense would have it, more obese people exercise less because they find physical activity less rewarding; or whether, as in the virtue theory of metabolism, lack of exercise actually causes weight gain due to divine punishment for the sin of sloth.

I recommend that Eliezer edit this post to remove this kind of provocation. The nature of the actual rationality message in this post is such that people are likely to link to it in the future (indeed, I found it via an external link myself). It even seems like something that may be intended to be part of a sequence. As it stands I expect many future references to be derailed and also expect to see this crop up prominently in lists of reasons to not take Eliezer's blog posts seriously. And, frankly, this reason would be a heck of a lot better than most others that are usually provided by detractors.