My dad often speaks infuriatingly slowly. When he finishes his spiels, I sometimes feel underwhelmed. The underwhelmedness comes from some sentiment that I could have generated similar speech in much less time.
Over the past year or so, however, encounters with people who speak rapidly have had me rethinking my attitude. I’ve noticed that I am sometimes impressed by people who talk fast. Usually they are, in fact, smart. I’ve also noticed that I am rarely persuaded. I update slightly in the direction of fast talkers being correct because they seem smart, or because I have a vague impression that they’ve thought about things for a while. But this is far from the state of being soundly convinced.
Often an unqualified observer, I find that information densities of rapidly-delivered speech and slowly-delivered speech feel comparable. This is why I imagine I’m able to generate speech more quickly than my dad - I’m responding to something like a probability distribution over word sequences rather than the words’ contextual significance, which I haven’t yet grokked. So measured speech doesn’t clearly have the advantage of perceived quality. What it does seem to have are trust and memorability.
My dad’s had more success than most anyone at convincing me of things he believes. There’s the obvious bit where his speaking slowly means that I know he’s thought critically about what he’s saying. What surprises me repeatedly, though, is how this trust interplays with the fact that I unwittingly keep a playback of his words in my head, possible because they were elegantly phrased and brief. I’ll scoff in the moment, but hours later I’m turning over his words again. I suppose I unconsciously give him the benefit of the doubt since I trust he was being thoughtful, and I continue to search for the signal that I didn’t catch the first time around. The signal is almost always there.
My dad and people like him get extra trust points in particular because I know they could speak rapidly if they wanted to and I wouldn’t be able to distinguish low-quality words from high-quality words. When they still choose to speak slowly, I have pretty good evidence that they care more about sharing truth than inflating their egos.
(A few other disadvantages of rapid speech: sometimes when a person talks very fast I’m unable to parse their words in the amount of time deemed socially acceptable for response generation, so the conversation ends early and I walk away having not addressed personal cruxes. Sometimes they make too many disputable claims and I can only respond to one, so the conversation branches and I haven’t taken away the main point. Sometimes I just have no idea what they’re saying.)
In short, I’ll claim that fast speech impresses, but measured speech persuades. Psychology seems to support this with a few caveats, although I won’t endorse any particular study. I am not suggesting that measured speech is always tactical. Maybe you want the credibility lent by fast speech that could pay out in the long term. Or maybe you just don’t have great arguments you can articulate at all, fast or slow. But if your goal is to persuade and you’re confident, you’ll do better (at least with me) if you think before you talk.