I can’t read facial expressions, and I’m bad with tone of voice, so I learned to analyze word choice and sentence structure. Give me a few paragraphs of a political post, and I might not be able to tell you what the speaker believes, but I can probably figure out what their friends believe. Phrases and rhythms have trends just like clothing. Each unnecessary flourish is a marker of who you hang out with and what arguments they’re likely to expose you to.
Some people have a very plain, straightforward style of speaking. It’s not necessarily simple, but they’ll use complex or technical terms only when those are the most appropriate words for what they want to express. They avoid metaphors, dislike obfuscation, and keep their emotions out of the argument unless you really piss them off. With no adornments, these people can be anything from anarchists to techno-capitalists to particularly atypical Platonists, and it’s quite difficult to guess before they directly express what they believe.
I’ve found that rationalists often speak in the straightforward style. I’ve also found that they are very sensitive to the idea of “reading too much in,” and go by the exact meaning of the other person’s words, without reference to some different person who also used those words. It’s understandable that you would be wary of guessing, if people guess wrong about you, and in some ways, it’s laudable not to jump to conclusions. But it also leads to a lot of time spent trying to reason with people whose speech patterns mark them as fanatical beyond convincing.