I presume that there is a joke in there somewhere, but I fail to see it.
I don't think it's a joke. I think paulfchristiano is saying that if we are interested in the effect treating studies like as reasons to change habits, then we should study the effects of changing behavior because of a study like this.
My roommate recently sent me a review article that LW might find interesting:
Personal observation says that LWers tend not to drink very much or often. Perhaps that should change, to the degree suggested by the article?
Full article here.