Imagine a substantive Less Wrong comment. It's insightful, polite, easy to understand, and otherwise good. Ideally, you upvote this comment. Now imagine the same comment, only with "obviously" in front. This shouldn't change much, but it does. This word seems to change the comment in multifarious bad ways that I'd rather not try to list.
Uncharitably, I might reduce this whole phenomenon to an example of a mind projection fallacy.
I have a different explanation: this is a status defense mechanism. If you say something that other people find obvious, in a way that suggests that you didn't find it obvious, you lose status-points for not being as smart as them. By adding the word "obviously", you in effect say "please do not infer that I think this remark is a great discovery of mine (and thus that I am ignorant relative to you) from the mere fact that I think it needs to be stated explicitly".
As an added benefit, if the remark turns out not to be obvious to your audience, yet demonstrably true, you gain status for having been smarter than them.
You might think, then, that there is no downside to simply prefacing every statement you think is true with "obviously". Obviously, however ( :-) ), you have to avoid making it transparent what you're doing, and thus restrict your usage of "obvious" to particularly plausible cases. Calibrating this sense of plausibility with your own epistemic powers is one of many mysterious (in the sense of not being spoken about or taught explicitly) techniques of human status negotiation. (And heaven help you if you label "obvious" something that is false...)
There is no reason an action like this can't have a compound cause. I would guess that, in the hypothetical, the person is not actually thinking "Okay, I'll preface this with 'obviously' so that I look good." However, it is likely that, since saying "obviously" is high status, they wouldn't think too hard about whether the thing is in fact obvious - certainly not as hard as if they were about to say something low status.
Related to: Generalizing from One Example, Connecting Your Beliefs (a call for help), Beware the Unsurprised
The idea of this article is something I've talked about a couple of times in comments. It seems to require more attention.
As a general rule, what is obvious to some people may not be obvious to others. Is this obvious to you? Maybe it was. Maybe it wasn't, and you thought it was because of hindsight bias.
Imagine a substantive Less Wrong comment. It's insightful, polite, easy to understand, and otherwise good. Ideally, you upvote this comment. Now imagine the same comment, only with "obviously" in front. This shouldn't change much, but it does. This word seems to change the comment in multifarious bad ways that I'd rather not try to list.
Uncharitably, I might reduce this whole phenomenon to an example of a mind projection fallacy. The implicit deduction goes like this: "I found <concept> obvious. Thus, <concept> is inherently obvious." The problem is that obviousness, like probability, is in the mind.
The stigma of "obvious" ideas has another problem in preventing things from being said at all. I don't know how common this is, but I've actually been afraid of saying things that I thought were obvious, even though ignoring this fear and just posting has yet to result in a poorly-received comment. (That is, in fact, why I'm writing this.)
Even tautologies, which are always obvious in retrospect, can be hard to spot. How many of us would have explicitly realized the weak anthropic principle without Nick Bostrom's help?
And what about implications of beliefs you already hold? These should be obvious, and sometimes are, but our brains are notoriously bad at putting two and two together. Luke's example was not realizing that an intelligence explosion was imminent until he read the I.J. Good paragraph. I'm glad he provided that example, as it has saved me the trouble of making one.
This is not (to paraphrase Eliezer) a thunderbolt of insight. I bring it up because I propose a few community norms based on the idea:
I'm not sure if these are good ideas, but I think implementing them would decrease the volume of thoughts we cannot think and things we can't say.