Two anecdotes are relevant here.
Lewis Carroll from the introduction to his Symbolic Logic:
If possible, find some genial friend, who will read the book along with you, and will talk over the difficulties with you. Talking is a wonderful smoother-over of difficulties. When I come upon anything——in Logic or in any other hard subject——that entirely puzzles me, I find it a capital plan to talk it over, aloud, even when I am all alone. One can explain things so clearly to one’s self! And then, you know, one is so patient with one’s self: one never gets irritated at one’s own stupidity!
And Henry Hazlitt from his Thinking As a Science:
Fortunately there is one method superior to any yet named, which requires no study before its application, and no paraphernalia during it. It consists in simply talking your thoughts as you think them. One who has not tried this can have no idea of its effect. It possesses almost all the advantages of writing. You cannot wander without realizing the fact immediately. It makes your thinking much less vague than if you thought silently, increases your vocabulary, always keeps pace with your ideas, and requires practically no attention.
It may be objected that silent thinking itself is put in unspoken words. But this is not true. Part of silent thinking consists of unspoken words, but part of it consists of images, concepts and attitudes which pass through our minds and which we do not take the trouble to name. In silent thinking, too, there are also what appear to be occasional dead stops. All these processes drift into each other indefinably and are unrecognizable. When we talk we realize whether our images or concepts are vague or definite by our ability to name them, and we realize when our thought comes to a ^ dead stop' by the fact that we miss the sound of our own voice.
[...] Talking has one disadvantage — it cannot always be used. To practice it, you must either lock yourself up in your room, or sit alone in a forest or field, or walk along unfrequented streets and by-ways. You can by no means allow any one to hear or see you talking to yourself. If you are caught doing this some asinine idiot is sure to mistake you for one.
I have returned from a particularly fruitful Google search, with unexpected results.
My question was simple. I was pretty sure that talking to myself aloud makes me temporarily better at solving problems that need a lot of working memory. It is a thinking tool that I find to be of great value, and that I imagine would be of interest to anyone who'd like to optimize their problem solving. I just wanted to collect some evidence on that, make sure I'm not deluding myself, and possibly learn how to enhance the effect.
This might be just lousy Googling on my part, but the evidence is surprisingly unclear and disorganized. There are at least three seperate Wiki pages for it. They don't link to each other. Instead they present the distinct models of three seperate fields: autocommunication in communication studies, semiotics and other cultural studies, intrapersonal communication ("self-talk" redirects here) in anthropology and (older) psychology and private speech in developmental psychology. The first is useless for my purpose, the second mentions "may increase concentration and retention" with no source, the third confirms my suspicion that this behavior boosts memory, motivation and creativity, but it only talks about children.
Google Scholar yields lots of sports-related results for "self-talk" because it can apparently improve the performance of athletes and if there's something that obviously needs the optimization power of psychology departments, it is competitive sports. For "intrapersonal communication" it has papers indicating it helps in language acquisition and in dealing with social anxiety. Both are dwarfed by the results for "private speech", which again focus on children. There's very little on "autocommunication" and what is there has nothing to do with the functioning of individual minds.
So there's a bunch of converging pieces of evidence supporting the usefulness of this behavior, but they're from several seperate fields that don't seem to have noticed each other very much. How often do you find that?
Let me quickly list a few ways that I find it plausible to imagine talking to yourself could enhance rational thought.
All told, if you're talking to yourself you should be more able to solve complex problems than somebody of your IQ who doesn't, although somebody of your IQ with a pen and a piece of paper should still outthink both of you.
Given all that, I'm surprised this doesn't appear to have been discussed on LessWrong. Honesty: Beyond Internal Truth comes close but goes past it. Again, this might be me failing to use a search engine, but I think this is worth more of our attention that it has gotten so far.
I'm now almost certain talking to myself is useful, and I already find hindsight bias trying to convince me I've always been so sure. But I wasn't - I was suspicious because talking to yourself is an early warning sign of schizophrenia, and is frequent in dementia. But in those cases, it might simply be an autoregulatory response to failing working memory, not a pathogenetic element. After all, its memory enhancing effect is what the developmental psychologists say the kids use it for. I do expect social stigma, which is why I avoid talking to myself when around uninvolved or unsympathetic people, but my solving of complex problems tends to happen away from those anyway so that hasn't been an issue really.
So, what do you think? Useful?